International Space Station

{{Excerpt|International Space Station programme#Conception}}

The ISS was originally intended to be a laboratory, observatory, and factory while providing transportation, maintenance, and a low Earth orbit staging base for possible future missions to the Moon, Mars, and asteroids. However, not all of the uses envisioned in the initial memorandum of understanding between NASA and Roscosmos have been realised.{{Cite web|url=http://www.nasa.gov/mission_pages/station/structure/elements/nasa_rsa.html|title=Memorandum of Understanding Between the National Aeronautics and Space Administration of the United States of America and the Russian Space Agency Concerning Cooperation on the Civil International Space Station|publisher=NASA|access-date=19 April 2009|url-status=dead|archive-url=https://web.archive.org/web/20151215114755/http://www.nasa.gov/mission_pages/station/structure/elements/nasa_rsa.html|archive-date=15 December 2015}} {{PD-notice}} In the 2010 United States National Space Policy, the ISS was given additional roles of serving commercial, diplomatic,{{Cite journal|url=https://www.sciencediplomacy.org/article/2012/research-and-diplomacy-350-kilometers-above-earth|title=Research and Diplomacy 350 Kilometers above the Earth: Lessons from the International Space Station|last=Payette|first=Julie|date=10 December 2012|url-status=live|archive-url=https://web.archive.org/web/20130306143438/https://www.sciencediplomacy.org/article/2012/research-and-diplomacy-350-kilometers-above-earth|archive-date=6 March 2013|issue=4|journal=Science & Diplomacy|volume=1}} and educational purposes.{{Cite web|url=https://obamawhitehouse.archives.gov/sites/default/files/national_space_policy_6-28-10.pdf|title=National Space Policy of the United States of America|date=28 June 2010|publisher=White House|access-date=20 July 2011|url-status=live|archive-url=https://web.archive.org/web/20231027102640/https://obamawhitehouse.archives.gov/sites/default/files/national_space_policy_6-28-10.pdf|archive-date=27 October 2023}} {{PD-notice}}

{{Main|Scientific research on the International Space Station}}

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| caption1 = Comet Lovejoy photographed during Expedition 30

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| caption2 = Michael Foale conducts an inspection of the Microgravity Science Glovebox during Expedition 8.

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| caption2 = CubeSats are deployed by the NanoRacks CubeSat Deployer.

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The ISS provides a platform to conduct scientific research, with power, data, cooling, and crew available to support experiments. Small uncrewed spacecraft can also provide platforms for experiments, especially those involving zero gravity and exposure to space, but space stations offer a long-term environment where studies can be performed potentially for decades, combined with ready access by human researchers.{{Cite press release|url=https://www3.nasa.gov/home/hqnews/2008/nov/HQ_08-296_ISS_10th_Anniversary.html|title=Nations Around the World Mark 10th Anniversary of International Space Station|last1=Trinidad|first1=Katherine|last2=Humphries|first2=Kelly|date=17 November 2008|publisher=NASA|id=08-296|access-date=6 March 2009|url-status=live|archive-url=https://web.archive.org/web/20220521030300/https://www.nasa.gov/home/hqnews/2008/nov/HQ_08-296_ISS_10th_Anniversary.html|archive-date=21 May 2022}} {{PD-notice}}

The ISS simplifies individual experiments by allowing groups of experiments to share the same launches and crew time. Research is conducted in a wide variety of fields, including astrobiology, astronomy, physical sciences, materials science, space weather, meteorology, and human research including space medicine and the life sciences.{{cite web|date=26 June 2007|title=Fields of Research|url=http://pdlprod3.hosc.msfc.nasa.gov/A-fieldsresearch/index.html|url-status=dead|archive-url=https://web.archive.org/web/20080123150641/http://pdlprod3.hosc.msfc.nasa.gov/A-fieldsresearch/index.html|archive-date=23 January 2008|publisher=NASA}}{{Cite web|date=26 June 2007|title=Getting on Board|url=http://pdlprod3.hosc.msfc.nasa.gov/B-gettingonboard/index.html|url-status=live|archive-url=https://web.archive.org/web/20071208091537/http://pdlprod3.hosc.msfc.nasa.gov/B-gettingonboard/index.html|archive-date=8 December 2007|publisher=NASA}} {{PD-notice}}{{cite web|year=2008|title=Monitor of All-sky X-ray Image (MAXI)|url=http://www.isas.jaxa.jp/e/forefront/2009/ueno/index.shtml|url-status=dead|archive-url=https://web.archive.org/web/20110722111152/http://www.isas.jaxa.jp/e/forefront/2009/ueno/index.shtml|archive-date=22 July 2011|access-date=12 March 2011|publisher=JAXA}}{{Cite web|url=https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Research/SOLAR_three_years_observing_and_ready_for_solar_maximum|title=SOLAR: three years observing and ready for solar maximum|date=11 March 2011|publisher=ESA|access-date=4 June 2023|url-status=live|archive-url=https://web.archive.org/web/20230810131833/https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Research/SOLAR_three_years_observing_and_ready_for_solar_maximum|archive-date=10 August 2023}} Scientists on Earth have timely access to the data and can suggest experimental modifications to the crew. If follow-on experiments are necessary, the routinely scheduled launches of resupply craft allows new hardware to be launched with relative ease. Crews fly expeditions of several months' duration, providing approximately 160 man-hours per week of labour with a crew of six. However, a considerable amount of crew time is taken up by station maintenance.{{Citation|url=https://www.scienceinschool.org/article/2009/the-international-space-station-life-in-space/|title=The International Space Station: life in space|last1=Hartevelt-Velani|first1=Shamim|last2=Walker|first2=Carl|last3=Elmann-Larsen|first3=Benny|date=23 November 2009|publisher=Science in School|access-date=17 February 2009|url-status=live|archive-url=https://web.archive.org/web/20230203232623/https://www.scienceinschool.org/article/2009/the-international-space-station-life-in-space/|archive-date=3 February 2023|issue=10}}

Perhaps the most notable ISS experiment is the Alpha Magnetic Spectrometer (AMS), which is intended to detect dark matter and answer other fundamental questions about our universe. According to NASA, the AMS is as important as the Hubble Space Telescope. Currently docked on station, it could not have been easily accommodated on a free flying satellite platform because of its power and bandwidth needs.{{Cite web|url=http://www.nasa.gov/mission_pages/shuttle/main/amsprocessing.html|title=AMS to Focus on Invisible Universe|date=18 March 2011|publisher=NASA|access-date=8 October 2011|url-status=dead|archive-url=https://web.archive.org/web/20230305123234/http://www.nasa.gov/mission_pages/shuttle/main/amsprocessing.html|archive-date=5 March 2023}} {{PD-notice}}{{Cite web|url=https://science.nasa.gov/science-news/science-at-nasa/2009/14aug_ams/|title=In Search of Antimatter Galaxies|date=14 August 2009|publisher=NASA|access-date=8 October 2011|url-status=dead|archive-url=https://web.archive.org/web/20230114162151/https://science.nasa.gov/science-news/science-at-nasa/2009/14aug_ams/|archive-date=14 January 2023}} {{PD-notice}} On 3 April 2013, scientists reported that hints of dark matter may have been detected by the AMS.{{Cite journal|url=https://boa.unimib.it/bitstream/10281/44680/1/2013_PhysRevLett.110.141102_positron_fraction.pdf|title=First Result from the Alpha Magnetic Spectrometer on the International Space Station: Precision Measurement of the Positron Fraction in Primary Cosmic Rays of 0.5–350 GeV|last=Aguilar, M. et al. (AMS Collaboration)|date=3 April 2013|page=141102|bibcode=2013PhRvL.110n1102A|doi=10.1103/PhysRevLett.110.141102|url-status=live|archive-url=https://web.archive.org/web/20230810132812/https://boa.unimib.it/bitstream/10281/44680/1/2013_PhysRevLett.110.141102_positron_fraction.pdf|archive-date=10 August 2023|journal=Physical Review Letters|volume=110|issue=14|pmid=25166975|doi-access=free|issn=0031-9007}}{{cite web|last=Staff|date=3 April 2013|title=First Result from the Alpha Magnetic Spectrometer Experiment|url=http://www.ams02.org/2013/04/first-results-from-the-alpha-magnetic-spectrometer-ams-experiment/|url-status=dead|archive-url=https://web.archive.org/web/20130408185229/http://www.ams02.org/2013/04/first-results-from-the-alpha-magnetic-spectrometer-ams-experiment/|archive-date=8 April 2013|access-date=3 April 2013|website=AMS Collaboration}}{{Cite news|last1=Heilprin|first1=John|last2=Borenstein|first2=Seth|date=3 April 2013|title=Scientists find hint of dark matter from cosmos|agency=Associated Press|url=http://apnews.excite.com/article/20130403/DA5E6JAG3.html|url-status=dead|access-date=3 April 2013|archive-url=https://web.archive.org/web/20130510152050/http://apnews.excite.com/article/20130403/DA5E6JAG3.html|archive-date=10 May 2013}}{{Cite news|url=https://www.bbc.co.uk/news/science-environment-22016504|title=Alpha Magnetic Spectrometer zeroes in on dark matter|last=Amos|first=Jonathan|date=3 April 2013|access-date=3 April 2013|url-status=live|archive-url=https://web.archive.org/web/20230812222642/https://www.bbc.com/news/science-environment-22016504|archive-date=12 August 2023|publisher=BBC News}}{{Cite press release|url=https://www.nasa.gov/news-release/nasa-tv-briefing-discusses-alpha-magnetic-spectrometer-results/|title=NASA TV Briefing Discusses Alpha Magnetic Spectrometer Results|last1=Perrotto|first1=Trent J.|last2=Byerly|first2=Josh|publisher=NASA|id=M13-054|access-date=3 April 2013|url-status=live|archive-url=https://web.archive.org/web/20231109114859/https://www.nasa.gov/news-release/nasa-tv-briefing-discusses-alpha-magnetic-spectrometer-results/|archive-date=9 November 2023}} {{PD-notice}}{{Cite news|last=Overbye|first=Dennis|date=3 April 2013|title=Tantalizing New Clues into the Mysteries of Dark Matter|work=The New York Times|url=https://www.nytimes.com/2013/04/04/science/space/new-clues-to-the-mystery-of-dark-matter.html|url-status=live|access-date=3 April 2013|archive-url=https://web.archive.org/web/20170820032900/https://www.nytimes.com/2013/04/04/science/space/new-clues-to-the-mystery-of-dark-matter.html|archive-date=20 August 2017}} According to the scientists, "The first results from the space-borne Alpha Magnetic Spectrometer confirm an unexplained excess of high-energy positrons in Earth-bound cosmic rays".{{Citation needed|date=June 2024}}

The space environment is hostile to life. Unprotected presence in space is characterised by an intense radiation field (consisting primarily of protons and other subatomic charged particles from the solar wind, in addition to cosmic rays), high vacuum, extreme temperatures, and microgravity.{{Cite journal|last1=Horneck|first1=Gerda|last2=Klaus|first2=David M.|last3=Mancinelli|first3=Rocco L.|date=March 2010|title=Space Microbiology|url=http://syntheticbiology.arc.nasa.gov/files/SpaceMicrobiology%20MMBR%201.pdf|url-status=dead|journal=Microbiology and Molecular Biology Reviews|publisher=American Society for Microbiology|volume=74|issue=1|pages=121–156|bibcode=2010MMBR...74..121H|doi=10.1128/MMBR.00016-09|pmc=2832349|pmid=20197502|archive-url=https://web.archive.org/web/20110830095643/http://syntheticbiology.arc.nasa.gov/files/SpaceMicrobiology%20MMBR%201.pdf|archive-date=30 August 2011|access-date=4 June 2011}} See Space Environment on p. 122. Some simple forms of life called extremophiles,{{Cite news|url=https://www.bbc.co.uk/news/science-environment-11039206|title=Beer microbes live 553 days outside ISS|last=Amos|first=Jonathan|date=23 August 2010|access-date=4 June 2011|url-status=live|archive-url=https://web.archive.org/web/20230811163449/https://www.bbc.com/news/science-environment-11039206|archive-date=11 August 2023|publisher=BBC News}} as well as small invertebrates called tardigrades{{Cite journal|last=Ledford|first=Heidi|date=8 September 2008|title=Spacesuits optional for 'water bears'|journal=Nature|doi=10.1038/news.2008.1087}} can survive in this environment in an extremely dry state through desiccation.

Medical research improves knowledge about the effects of long-term space exposure on the human body, including muscle atrophy, bone loss, and fluid shift. These data will be used to determine whether high duration human spaceflight and space colonisation are feasible. In 2006, data on bone loss and muscular atrophy suggested that there would be a significant risk of fractures and movement problems if astronauts landed on a planet after a lengthy interplanetary cruise, such as the six-month interval required to travel to Mars.{{Cite book|first=Jay|last=Buckey|title=Space Physiology|date=23 February 2006|publisher=Oxford University Press USA|isbn=978-0-19-513725-5}}{{Cite magazine|url=https://www.newscientist.com/article/dn17476-ion-engine-could-one-day-power-39-day-trips-to-mars/|title=Ion engine could one day power 39-day trips to Mars|last=Grossman|first=List|date=22 July 2009|access-date=8 January 2010|url-status=live|archive-url=https://web.archive.org/web/20231015103957/https://www.newscientist.com/article/dn17476-ion-engine-could-one-day-power-39-day-trips-to-mars/|archive-date=15 October 2023|magazine=New Scientist}}

Medical studies are conducted aboard the ISS on behalf of the National Space Biomedical Research Institute (NSBRI). Prominent among these is the Advanced Diagnostic Ultrasound in Microgravity study in which astronauts perform ultrasound scans under the guidance of remote experts. The study considers the diagnosis and treatment of medical conditions in space. Usually, there is no physician on board the ISS and diagnosis of medical conditions is a challenge. It is anticipated that remotely guided ultrasound scans will have application on Earth in emergency and rural care situations where access to a trained physician is difficult.{{Cite web|url=http://www.nasa.gov/mission_pages/station/science/experiments/ADUM.html|title=Advanced Diagnostic Ultrasound in Microgravity (ADUM)|last=Boen|first=Brooke|date=1 May 2009|publisher=NASA|access-date=1 October 2009|url-status=dead|archive-url=https://web.archive.org/web/20091029061057/http://www.nasa.gov/mission_pages/station/science/experiments/ADUM.html|archive-date=29 October 2009}} {{PD-notice}}{{Cite journal|last1=Rao|first1=Sishir|last2=van Holsbeeck|first2=Lodewijk|last3=Musial|first3=Joseph L.|last4=Parker|first4=Alton|last5=Bouffard|first5=J. Antonio|last6=Bridge|first6=Patrick|last7=Jackson|first7=Matt|last8=Dulchavsky|first8=Scott A.|display-authors=1|date=May 2008|title=A Pilot Study of Comprehensive Ultrasound Education at the Wayne State University School of Medicine|journal=Journal of Ultrasound in Medicine|volume=27|issue=5|pages=745–749|doi=10.7863/jum.2008.27.5.745|pmid=18424650|s2cid=30566494|doi-access=free}}{{Cite journal|last1=Fincke|first1=E. Michael|last2=Padalka|first2=Gennady|last3=Lee|first3=Doohi|last4=van Holsbeeck|first4=Marnix|last5=Sargsyan|first5=Ashot E.|last6=Hamilton|first6=Douglas R.|last7=Martin|first7=David|last8=Melton|first8=Shannon L.|last9=McFarlin|first9=Kellie |last10=Dulchavsky |first10=Scott A.|display-authors=1|date=February 2005|title=Evaluation of Shoulder Integrity in Space: First Report of Musculoskeletal US on the International Space Station|journal=Radiology|volume=234|issue=2|pages=319–322|doi=10.1148/radiol.2342041680|pmid=15533948}}

In August 2020, scientists reported that bacteria from Earth, particularly Deinococcus radiodurans bacteria, which is highly resistant to environmental hazards, were found to survive for three years in outer space, based on studies conducted on the International Space Station. These findings supported the notion of panspermia, the hypothesis that life exists throughout the Universe, distributed in various ways, including space dust, meteoroids, asteroids, comets, planetoids or contaminated spacecraft.{{Cite news|url=https://www.cnn.com/2020/08/26/world/earth-mars-bacteria-space-scn/index.html|title=Bacteria from Earth can survive in space and could endure the trip to Mars, according to new study|last=Strickland|first=Ashley|date=26 August 2020|access-date=26 August 2020|url-status=live|archive-url=https://web.archive.org/web/20230811171442/https://edition.cnn.com/2020/08/26/world/earth-mars-bacteria-space-scn/index.html|archive-date=11 August 2023|publisher=CNN}}{{Cite journal|last=Kawaguchi|first=Yuko|display-authors=et al.|date=26 August 2020|title=DNA Damage and Survival Time Course of Deinococcal Cell Pellets During 3 Years of Exposure to Outer Space|journal=Frontiers in Microbiology|volume=11|page=2050|doi=10.3389/fmicb.2020.02050|pmid=32983036|pmc=7479814|s2cid=221300151|doi-access=free}}

Remote sensing of the Earth, astronomy, and deep space research on the ISS have significantly increased during the 2010s after the completion of the US Orbital Segment in 2011. Throughout the more than 20 years of the ISS program, researchers aboard the ISS and on the ground have examined aerosols, ozone, lightning, and oxides in Earth's atmosphere, as well as the Sun, cosmic rays, cosmic dust, antimatter, and dark matter in the universe. Examples of Earth-viewing remote sensing experiments that have flown on the ISS are the Orbiting Carbon Observatory 3, ISS-RapidScat, ECOSTRESS, the Global Ecosystem Dynamics Investigation, and the Cloud Aerosol Transport System. ISS-based astronomy telescopes and experiments include SOLAR, the Neutron Star Interior Composition Explorer, the Calorimetric Electron Telescope, the Monitor of All-sky X-ray Image (MAXI), and the Alpha Magnetic Spectrometer.{{Cite web|url=https://eol.jsc.nasa.gov/ESRS/ISS_Remote_Sensing_Systems/|title=Earth Science & Remote Sensing Missions on ISS|publisher=NASA|access-date=9 December 2020|url-status=live|archive-url=https://web.archive.org/web/20230810131526/https://eol.jsc.nasa.gov/ESRS/ISS_Remote_Sensing_Systems/|archive-date=10 August 2023}}

File:ISS-20 Robert Thirsk at the Minus Eighty Degree Laboratory Freezer.jpg

File:Space Fire.jpg (left) and in a free fall environment, such as that found on the ISS (right)]]

Gravity at the altitude of the ISS is approximately 90% as strong as at Earth's surface, but objects in orbit are in a continuous state of freefall, resulting in an apparent state of weightlessness.{{Cite web|last=May|first=Sandra|date=15 February 2012|title=What Is Microgravity?|url=https://www.nasa.gov/learning-resources/for-kids-and-students/what-is-microgravity-grades-5-8/|url-status=live|archive-url=https://web.archive.org/web/20231107174300/https://www.nasa.gov/learning-resources/for-kids-and-students/what-is-microgravity-grades-5-8/|archive-date=7 November 2023|access-date=3 September 2018|series=NASA Knows! (Grades 5–8)|publisher=NASA}} {{PD-notice}} This perceived weightlessness is disturbed by five effects:{{cite web|date=6 December 2005|title=European Users Guide to Low Gravity Platforms|url=http://www.esa.int/Our_Activities/Human_Spaceflight/Human_Spaceflight_Research/European_User_Guide_to_Low-Gravity_Platforms|url-status=dead|archive-url=https://web.archive.org/web/20130402225556/http://www.esa.int/Our_Activities/Human_Spaceflight/Human_Spaceflight_Research/European_User_Guide_to_Low-Gravity_Platforms|archive-date=2 April 2013|access-date=22 March 2013|publisher=European Space Agency}}

• Drag from the residual atmosphere.
• Vibration from the movements of mechanical systems and the crew.
• Actuation of the on-board attitude control moment gyroscopes.
• Thruster firings for attitude or orbital changes.
• Gravity-gradient effects, also known as tidal effects. Items at different locations within the ISS would, if not attached to the station, follow slightly different orbits. Being mechanically connected, these items experience small forces that keep the station moving as a rigid body.

Researchers are investigating the effect of the station's near-weightless environment on the evolution, development, growth and internal processes of plants and animals. In response to some of the data, NASA wants to investigate microgravity's effects on the growth of three-dimensional, human-like tissues and the unusual protein crystals that can be formed in space.

Investigating the physics of fluids in microgravity will provide better models of the behaviour of fluids. Because fluids can be almost completely combined in microgravity, physicists investigate fluids that do not mix well on Earth. Examining reactions that are slowed by low gravity and low temperatures will improve our understanding of superconductivity.

The study of materials science is an important ISS research activity, with the objective of reaping economic benefits through the improvement of techniques used on Earth.{{Cite web|url=https://science.nasa.gov/newhome/headlines/msad15sep99_1.htm|title=Materials Science 101|date=15 September 1999|publisher=NASA|access-date=18 June 2009|url-status=dead|archive-url=https://web.archive.org/web/20090614033947/http://science.nasa.gov/newhome/headlines/msad15sep99_1.htm|archive-date=14 June 2009}} {{PD-notice}} Other areas of interest include the effect of low gravity on combustion, through the study of the efficiency of burning and control of emissions and pollutants. These findings may improve knowledge about energy production and lead to economic and environmental benefits.

File:Mars500.jpg complex, used for conducting ground-based experiments that complement ISS-based preparations for a human mission to Mars]]

The ISS provides a location in the relative safety of low Earth orbit to test spacecraft systems that will be required for long-duration missions to the Moon and Mars. This provides experience in operations, maintenance, and repair and replacement activities on-orbit. This will help develop essential skills in operating spacecraft farther from Earth, reduce mission risks, and advance the capabilities of interplanetary spacecraft.{{cite web|title=ISS Research Program|url=http://spaceflightsystems.grc.nasa.gov/Advanced/ISSResearch/|url-status=dead|archive-url=https://web.archive.org/web/20090213140014/http://spaceflightsystems.grc.nasa.gov/Advanced/ISSResearch/|archive-date=13 February 2009|access-date=27 February 2009|publisher=NASA}} Referring to the MARS-500 experiment, a crew isolation experiment conducted on Earth, ESA states, "Whereas the ISS is essential for answering questions concerning the possible impact of weightlessness, radiation and other space-specific factors, aspects such as the effect of long-term isolation and confinement can be more appropriately addressed via ground-based simulations".{{Cite web|url=https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Mars500/Mars500_study_overview|title=Mars500: study overview|date=4 June 2011|publisher=European Space Agency|url-status=live|archive-url=https://web.archive.org/web/20230819135747/https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Mars500/Mars500_study_overview|archive-date=19 August 2023}} Sergey Krasnov, the head of human space flight programmes for Russia's space agency, Roscosmos, in 2011 suggested a "shorter version" of MARS-500 may be carried out on the ISS.{{cite web|date=4 November 2011|title=Space station may be site for next mock Mars mission|url=https://www.newscientist.com/blogs/shortsharpscience/2011/11/space-station-may-be-site-for.html|website=New Scientist|access-date=1 September 2017|archive-date=11 July 2017|archive-url=https://web.archive.org/web/20170711030614/https://www.newscientist.com/blogs/shortsharpscience/2011/11/space-station-may-be-site-for.html|url-status=dead}}

In 2009, noting the value of the partnership framework itself, Sergey Krasnov wrote, "When compared with partners acting separately, partners developing complementary abilities and resources could give us much more assurance of the success and safety of space exploration. The ISS is helping further advance near-Earth space exploration and realisation of prospective programmes of research and exploration of the Solar system, including the Moon and Mars."{{cite web|title=The Sustainable Utilisation of the ISS Beyond 2015|url=http://www.iafastro.org/docs/2009/ISS2015.pdf|url-status=dead|archive-url=https://web.archive.org/web/20120426051318/http://www.iafastro.org/docs/2009/ISS2015.pdf|archive-date=26 April 2012|access-date=15 December 2011|publisher=International Astronautical Congress}} A crewed mission to Mars may be a multinational effort involving space agencies and countries outside the current ISS partnership. In 2010, ESA Director-General Jean-Jacques Dordain stated his agency was ready to propose to the other four partners that China, India, and South Korea be invited to join the ISS partnership.{{Cite news|last=de Selding|first=Peter B.|date=3 February 2010|title=ESA Chief Lauds Renewed U.S. Commitment to Space Station, Earth Science|work=Space News|url=http://spacenews.com/esa-chief-lauds-renewed-us-commitment-space-station-earth-science/}} NASA chief Charles Bolden stated in February 2011, "Any mission to Mars is likely to be a global effort."{{Cite news|url=https://www.space.com/11335-nasa-mars-exploration-space-station.html|title=Space Station Crucial for Going to Mars, NASA Chief Says|last=Chow|first=Denise|date=8 April 2011|url-status=live|archive-url=https://web.archive.org/web/20230811162758/https://www.space.com/11335-nasa-mars-exploration-space-station.html|archive-date=11 August 2023|work=Space.com}} Currently, US federal legislation prevents NASA co-operation with China on space projects without approval by the FBI and Congress.{{cite web|last=Seitz|first=Virginia A.|title=Memorandum Opinion for the General Counsel, Office of Science and Technology Policy|date=19 September 2011|url=https://www.justice.gov/olc/2011/conduct-diplomacy.pdf|website=justice.gov|publisher=US Justice Department|archive-url=https://web.archive.org/web/20120713080223/http://www.justice.gov/olc/2011/conduct-diplomacy.pdf|access-date=23 May 2012|archive-date=13 July 2012|url-status=dead|page=3}}

File:Crew in ATV with Jules Verne manuscript.jpg manuscripts displayed by crew inside the Jules Verne ATV (Automated Transfer Vehicle)]]

The ISS crew provides opportunities for students on Earth by running student-developed experiments, making educational demonstrations, allowing for student participation in classroom versions of ISS experiments, and directly engaging students using radio, and email.{{Cite book|last=Kitmacher|first=Gary|title=Reference Guide to the International Space Station|publisher=Apogee Books|year=2006|isbn=978-1-894959-34-6|series=Apogee Books Space Series|location=Canada|pages=71–80|issn=1496-6921}}{{Cite journal|last1=Sandal|first1=Gro M.|last2=Manzey|first2=Dietrich|date=December 2009|title=Cross-cultural issues in space operations: A survey study among ground personnel of the European Space Agency|url=https://www.researchgate.net/publication/222963564|journal=Acta Astronautica|volume=65|issue=11–12|pages=1520–1529|bibcode=2009AcAau..65.1520S|doi=10.1016/j.actaastro.2009.03.074|issn=0094-5765}} ESA offers a wide range of free teaching materials that can be downloaded for use in classrooms.{{Cite web|url=https://www.esa.int/Education/Online_material|title=Online Materials|publisher=European Space Agency|access-date=3 April 2016|url-status=live|archive-url=https://web.archive.org/web/20230811162359/https://www.esa.int/Education/Online_material|archive-date=11 August 2023}} In one lesson, students can navigate a 3D model of the interior and exterior of the ISS, and face spontaneous challenges to solve in real time.{{Cite web|url=https://www.esa.int/Education/ISS_3-D_Teaching_Tool_Spaceflight_Challenge_I|title=ISS 3-D Teaching Tool: Spaceflight Challenge I|date=24 May 2011|publisher=European Space Agency|access-date=8 October 2011|url-status=live|archive-url=https://web.archive.org/web/20230811164504/https://www.esa.int/Education/ISS_3-D_Teaching_Tool_Spaceflight_Challenge_I|archive-date=11 August 2023}}

The Japanese Aerospace Exploration Agency (JAXA) aims to inspire children to "pursue craftsmanship" and to heighten their "awareness of the importance of life and their responsibilities in society".{{Cite conference|url=https://www.unoosa.org/pdf/pres/copuos2010/tech-17E.pdf|title=Building Peace in Young Minds through Space Education|date=June 2010|publisher=JAXA|location=Vienna, Austria|url-status=live|archive-url=https://web.archive.org/web/20230811162718/https://www.unoosa.org/pdf/pres/copuos2010/tech-17E.pdf|archive-date=11 August 2023|conference=Committee on the Peaceful Uses of Outer Space|volume=53}} Through a series of education guides, students develop a deeper understanding of the past and near-term future of crewed space flight, as well as that of Earth and life.{{Cite web|url=http://www.edu.jaxa.jp/education/international/ISS/SSK/en/|title=JAXA Spaceflight Seeds Kids I : Spaceflight Sunflower seeds – Let's make them flower! and learn freshly the Earth environment just by contrast with the Space one|year=2006|publisher=JAXA|url-status=dead|archive-url=https://web.archive.org/web/20120318025859/http://www.edu.jaxa.jp/education/international/ISS/SSK/en/|archive-date=18 March 2012}}{{Cite web|url=http://www.edu.jaxa.jp/education/international/ISS/SIS/en/|title=JAXA Seeds in Space I : Let's Cultivate Spaceflight Asagao (Japanese morning glory), Miyako-gusa (Japanese bird's foot trefoil) Seeds and Identify the Mutants!|year=2006|publisher=JAXA|url-status=dead|archive-url=https://web.archive.org/web/20120318025023/http://www.edu.jaxa.jp/education/international/ISS/SIS/en/|archive-date=18 March 2012}} In the JAXA "Seeds in Space" experiments, the mutation effects of spaceflight on plant seeds aboard the ISS are explored by growing sunflower seeds that have flown on the ISS for about nine months. In the first phase of Kibō utilisation from 2008 to mid-2010, researchers from more than a dozen Japanese universities conducted experiments in diverse fields.{{cite web|first=Keiji|last=Murakami|date=14 October 2009|title=JEM Utilization Overview|url=http://www.spacepolicyonline.com/pages/images/stories/Micro%20Oct%2009%20JEM.pdf|publisher=JAXA. Steering Committee for the Decadal Survey on Biological and Physical Sciences in Space|access-date=27 September 2011|archive-date=29 November 2011|archive-url=https://web.archive.org/web/20111129141828/http://www.spacepolicyonline.com/pages/images/stories/Micro%20Oct%2009%20JEM.pdf|url-status=dead}}

Cultural activities are another major objective of the ISS programme. Tetsuo Tanaka, the director of JAXA's Space Environment and Utilization Center, has said: "There is something about space that touches even people who are not interested in science."{{cite web|first=Tetsuo|last=Tanaka|title=Kibo: Japan's First Human Space Facility|url=http://www.jaxa.jp/article/special/kibo/tanaka01_e.html|access-date=8 October 2011|publisher=JAXA|archive-date=29 November 2011|archive-url=https://web.archive.org/web/20111129145716/http://www.jaxa.jp/article/special/kibo/tanaka01_e.html|url-status=dead}}

Amateur Radio on the ISS (ARISS) is a volunteer programme that encourages students worldwide to pursue careers in science, technology, engineering, and mathematics, through amateur radio communications opportunities with the ISS crew. ARISS is an international working group, consisting of delegations from nine countries including several in Europe, as well as Japan, Russia, Canada, and the United States. In areas where radio equipment cannot be used, speakerphones connect students to ground stations which then connect the calls to the space station.{{cite web|date=6 June 2011|title=Amateur Radio on the International Space Station|url=http://www.rac.ca/ariss/oindex.htm|url-status=dead|archive-url=https://web.archive.org/web/20110527071557/http://www.rac.ca/ariss/oindex.htm|archive-date=27 May 2011|access-date=10 June 2011}}

File:ESA-Astronaut-Paolo-Nespoli Voice-intro-ENG.flac on the subject of the ISS, produced in November 2017 for Wikipedia]]

First Orbit is a 2011 feature-length documentary film about Vostok 1, the first crewed space flight around the Earth. By matching the orbit of the ISS to that of Vostok 1 as closely as possible, in terms of ground path and time of day, documentary filmmaker Christopher Riley and ESA astronaut Paolo Nespoli were able to film the view that Yuri Gagarin saw on his pioneering orbital space flight. This new footage was cut together with the original Vostok 1 mission audio recordings sourced from the Russian State Archive. Nespoli is credited as the director of photography for this documentary film, as he recorded the majority of the footage himself during Expedition 26/27.{{Cite news|url=https://www.theguardian.com/science/blog/2011/apr/11/yuri-gagarin-first-orbit-vostok|title=What Yuri Gagarin saw: First Orbit film to reveal the view from Vostok 1|last=Riley|first=Christopher|date=11 April 2011|url-status=live|archive-url=https://web.archive.org/web/20230810132648/https://www.theguardian.com/science/blog/2011/apr/11/yuri-gagarin-first-orbit-vostok|archive-date=10 August 2023|work=The Guardian}} The film was streamed in a global YouTube premiere in 2011 under a free licence through the website firstorbit.org.{{Cite web|url=https://www.firstorbit.org/first-orbit-faqs|title=Yuri Gagarin's First Orbit – FAQs|publisher=The Attic Room Ltd|access-date=1 May 2012|url-status=live|archive-url=https://web.archive.org/web/20230810131924/http://www.firstorbit.org/first-orbit-faqs|archive-date=10 August 2023|website=firstorbit.org}}

In May 2013, commander Chris Hadfield shot a music video of David Bowie's "Space Oddity" on board the station, which was released on YouTube.{{Cite magazine|last=Warr|first=Philippa|date=13 May 2013|title=Commander Hadfield bids farewell to ISS with Reddit-inspired Bowie cover|url=https://www.wired.co.uk/news/archive/2013-05/13/commander-hadfield-space-oddity|url-status=dead|archive-url=https://web.archive.org/web/20131012212949/http://www.wired.co.uk/news/archive/2013-05/13/commander-hadfield-space-oddity|archive-date=12 October 2013|access-date=22 October 2013|magazine=Wired}}{{Cite news|url=https://www.bbc.co.uk/news/av/science-environment-22506395|title=Astronaut bids farewell with Bowie cover version (inc. video)|date=13 May 2013|access-date=24 September 2020|url-status=live|archive-url=https://web.archive.org/web/20230811163327/https://www.bbc.com/news/av/science-environment-22506395|archive-date=11 August 2023|publisher=BBC News}} It was the first music video filmed in space.{{Cite web|url=https://io9.gizmodo.com/chris-hadfield-sings-space-oddity-in-the-first-music-503764317|title=Chris Hadfield sings 'Space Oddity' in the first music video in space|last=Davis|first=Lauren|date=12 May 2013|url-status=live|archive-url=https://web.archive.org/web/20230811163440/https://gizmodo.com/chris-hadfield-sings-space-oddity-in-the-first-music-503764317|archive-date=11 August 2023|website=Gizmodo}}

In November 2017, while participating in Expedition 52/53 on the ISS, Paolo Nespoli made two recordings of his spoken voice (one in English and the other in his native Italian), for use on Wikipedia articles. These were the first content made in space specifically for Wikipedia.{{Cite web|url=https://blog.wikimedia.org/2017/11/29/astronaut-spoken-voice/|title=Close encounters of the Wikipedia kind: Astronaut is first to specifically contribute to Wikipedia from space|last=Mabbett|first=Andy|date=29 November 2017|publisher=Wikimedia foundation|access-date=4 December 2017|url-status=live|archive-url=https://web.archive.org/web/20230604132523/https://diff.wikimedia.org/2017/11/29/astronaut-spoken-voice/|archive-date=4 June 2023|website=Diff}}{{Cite news|url=https://www.meteoweb.eu/2017/12/primo-contributo-extraterrestre-wikipedia-nespoli/1009617/|title=Primo contributo 'extraterrestre' su Wikipedia: è di Nespoli|trans-title=First 'Extraterrestrial' Contribution on Wikipedia: It's by Nespoli.|last=Petris|first=Antonella|date=1 December 2017|language=it-IT|access-date=4 December 2017|url-status=live|archive-url=https://web.archive.org/web/20230811173118/https://www.meteoweb.eu/2017/12/primo-contributo-extraterrestre-wikipedia-nespoli/1009617/|archive-date=11 August 2023|work=Meteo Web}}

In November 2021, a virtual reality exhibit called The Infinite featuring life aboard the ISS was announced.{{Cite news|url=https://www.space.com/the-infinite-space-station-vr-houston|title='The Infinite' VR space station tour to premiere spacewalk in Houston|last=Pearlman|first=Robert Z.|date=23 November 2021|access-date=27 November 2021|url-status=live|archive-url=https://web.archive.org/web/20230810144311/https://www.space.com/the-infinite-space-station-vr-houston|archive-date=10 August 2023|website=Space.com}}

{{main|Manufacture of the International Space Station}}

File:SSPF interior.jpg in the Space Station Processing Facility]]

The International Space Station is a product of global collaboration, with its components manufactured across the world.

The modules of the Russian Orbital Segment, including Zarya and Zvezda, were produced at the Khrunichev State Research and Production Space Center in Moscow. Zvezda was initially manufactured in 1985 as a component for the Mir-2 space station, which was never launched.{{cite web|title=Building ISS|url=https://nara.getarchive.net/collections/building-iss-timeline|url-status=live|archive-url=https://web.archive.org/web/20211028222416/https://nara.getarchive.net/collections/building-iss-timeline|archive-date=28 October 2021|access-date=28 October 2021|website=U.S. National Archives & DVIDS}} {{PD-notice}}{{cite web|last=|title=ISS Zvezda|url=http://www.astronautix.com/i/isszvezda.html|url-status=dead|archive-url=https://web.archive.org/web/20160820144918/http://www.astronautix.com/i/isszvezda.html|archive-date=20 August 2016|access-date=5 July 2019}}

Much of the US Orbital Segment, including the Destiny and Unity modules, the Integrated Truss Structure, and solar arrays, were built at NASA's Marshall Space Flight Center in Huntsville, Alabama and Michoud Assembly Facility in New Orleans. These components underwent final assembly and processing for launch at the Operations and Checkout Building and the Space Station Processing Facility (SSPF) at the Kennedy Space Center in Florida.{{Cite web|date=19 February 2016|editor-last=Harbaugh|editor-first=Jennifer|title=Manufacturing Key Parts of the International Space Station: Unity and Destiny|url=https://www.nasa.gov/centers/marshall/history/stations/images/manufacturing-key-parts-of-ISS-unity-and-destiny|url-status=live|archive-url=https://web.archive.org/web/20231124184657/https://www.nasa.gov/image-article/manufacturing-key-parts-of-international-space-station-unity-destiny/|archive-date=24 November 2023|access-date=15 February 2019|publisher=NASA}}

The US Orbital Segment also hosts the Columbus module contributed by the European Space Agency and built in Germany, the Kibō module contributed by Japan and built at the Tsukuba Space Center and the Institute of Space and Astronautical Science, along with the Canadarm2 and Dextre, a joint Canadian-U.S. endeavor. All of these components were shipped to the SSPF for launch processing.{{Cite web|last=Shiflett|first=Kim|date=22 April 2008|title=KSC-08pd0991|url=https://images.nasa.gov/details/KSC-08pd0991|url-status=live|archive-url=https://web.archive.org/web/20231124185310/https://images.nasa.gov/details/KSC-08pd0991|archive-date=24 November 2023|access-date=5 July 2019|website=NASA Image and Video Library|quote=In the Space Station Processing Facility at NASA's Kennedy Space Center, an overhead crane moves the Kibo Japanese Experiment Module – Pressurized Module toward the payload canister (lower right). The canister will deliver the module, part of the payload for space shuttle Discovery's STS-124 mission, to Launch Pad 39A. On the mission, the STS-124 crew will transport the Kibo module as well as the Japanese Remote Manipulator System to the International Space Station to complete the Kibo laboratory. The launch of Discovery is targeted for May 31.|location=Cape Canaveral, Florida}}

{{main|Assembly of the International Space Station|List of ISS spacewalks}}

File:ISS-assembly-animation.gif]]

The assembly of the International Space Station, a major endeavour in space architecture, began in November 1998.{{cite web|date=18 February 2010|title=On-Orbit Elements|url=http://www.nasa.gov/externalflash/ISSRG/pdfs/on_orbit.pdf|url-status=dead|archive-url=https://web.archive.org/web/20091029013438/http://www.nasa.gov/externalflash/ISSRG/pdfs/on_orbit.pdf|archive-date=29 October 2009|access-date=19 June 2010|publisher=NASA}}

Modules in the Russian segment launched and docked autonomously, with the exception of Rassvet. Other modules and components were delivered by the Space Shuttle, which then had to be installed by astronauts either remotely using robotic arms or during spacewalks, more formally known as extra-vehicular activities (EVAs). By 5 June 2011 astronauts had made over 159 EVAs to add components to the station, totaling more than 1,000 hours in space.{{cite web|date=9 March 2011|title=The ISS to Date|url=http://www.nasa.gov/mission_pages/station/structure/isstodate.html|url-status=dead|archive-url=https://web.archive.org/web/20150611163133/http://www.nasa.gov/mission_pages/station/structure/isstodate.html|archive-date=11 June 2015|access-date=21 March 2011|publisher=NASA}}{{cite web|last=Dismukes|first=Kim |date=1 December 2002|title=Mission Control Answers Your Questions: STS-113 Q17|url=http://spaceflight.nasa.gov/feedback/expert/answer/mcc/sts-113/11_23_20_01_179.html|url-status=dead|archive-url=https://web.archive.org/web/20200724020141/https://spaceflight.nasa.gov/feedback/expert/answer/mcc/sts-113/11_23_20_01_179.html|archive-date=24 July 2020|access-date=14 June 2009|website=spaceflight.nasa.gov|publisher=NASA}}

File:ISS from Atlantis - Sts101-714-016.jpg

The foundation for the ISS was laid with the launch of the Russian-built Zarya module atop a Proton rocket on 20 November 1998. Zarya provided propulsion, attitude control, communications, and electrical power. Two weeks later on 4 December 1998, the American-made Unity was ferried aboard Space Shuttle Endeavour on STS-88 and joined with Zarya. Unity provided the connection between the Russian and US segments of the station and would provide ports to connect future modules and visiting spacecraft.

While the connection of two modules built on different continents, by nations that were once bitter rivals was a significant milestone, these two initial modules lacked life support systems and the ISS remained unmanned for the next two years. At the time, the Russian station Mir was still inhabited.

The turning point arrived in July 2000 with the launch of the Zvezda module. Equipped with living quarters and life-support systems, Zvezda enabled continuous human presence aboard the station. The first crew, Expedition 1, arrived that November aboard Soyuz TM-31.{{cite web|date=January 1999|title=NASA Facts. The Service Module: A Cornerstone of Russian International Space Station Modules|url=http://spaceflight.nasa.gov/spacenews/factsheets/pdfs/servmod.pdf|url-status=dead|archive-url=https://web.archive.org/web/20200823230702/https://spaceflight.nasa.gov/spacenews/factsheets/pdfs/servmod.pdf|archive-date=23 August 2020|website=spaceflight.nasa.gov|publisher=NASA|id=IS-1999-09-ISS019JSC}}{{cite web|title=STS-88|url=http://science.ksc.nasa.gov/shuttle/missions/sts-88/mission-sts-88.html|url-status=dead|archive-url=https://web.archive.org/web/20110606073849/http://science.ksc.nasa.gov/shuttle/missions/sts-88/mission-sts-88.html|archive-date=6 June 2011|access-date=19 April 2011|publisher=Science.ksc.nasa.gov}}

The ISS grew steadily over the following years, with modules delivered by both Russian rockets and the Space Shuttle.

Expedition 1 arrived midway between the Space Shuttle flights of missions STS-92 and STS-97. These two flights each added segments of the station's Integrated Truss Structure, which provided the station with Ku band communications, additional attitude control needed for the additional mass of the USOS, and additional solar arrays.{{cite web|title=STS-92|url=http://science.ksc.nasa.gov/shuttle/missions/sts-92/mission-sts-92.html|url-status=dead|archive-url=https://web.archive.org/web/20110305072211/http://science.ksc.nasa.gov/shuttle/missions/sts-92/mission-sts-92.html|archive-date=5 March 2011|access-date=19 April 2011|publisher=Science.ksc.nasa.gov}} Over the next two years, the station continued to expand. A Soyuz-U rocket delivered the Pirs docking compartment. The Space Shuttles Discovery, Atlantis, and Endeavour delivered the American Destiny laboratory and Quest airlock, in addition to the station's main robot arm, the Canadarm2, and several more segments of the Integrated Truss Structure.

Tragedy struck in 2003 with the loss of the Space Shuttle Columbia, which grounded the rest of the Shuttle fleet, halting construction of the ISS.File:International Space Station after undocking of STS-132.jpg, pictured in May 2010]]Assembly resumed in 2006 with the arrival of STS-115 with Atlantis, which delivered the station's second set of solar arrays. Several more truss segments and a third set of arrays were delivered on STS-116, STS-117, and STS-118. As a result of the major expansion of the station's power-generating capabilities, more modules could be accommodated, and the US Harmony module and Columbus European laboratory were added. These were soon followed by the first two components of the Japanese Kibō laboratory. In March 2009, STS-119 completed the Integrated Truss Structure with the installation of the fourth and final set of solar arrays. The final section of Kibō was delivered in July 2009 on STS-127, followed by the Russian Poisk module. The US Tranquility module was delivered in February 2010 during STS-130, alongside the Cupola, followed by the penultimate Russian module, Rassvet, in May 2010. Rassvet was delivered by Space Shuttle Atlantis on STS-132 in exchange for the Russian Proton delivery of the US-funded Zarya module in 1998.{{cite web|title=Mini-Research Module 1 (MIM1) Rassvet (MRM-1)|url=http://www.russianspaceweb.com/iss_mim1.html|url-status=dead|archive-url=https://web.archive.org/web/20110825094354/http://www.russianspaceweb.com/iss_mim1.html|archive-date=25 August 2011|access-date=12 July 2011|website=RussianSpaceWeb}} The last pressurised module of the USOS, Leonardo, was brought to the station in February 2011 on the final flight of Discovery, STS-133.{{Cite web|title=STS-133|url=https://www.nasa.gov/mission/sts-133/|url-status=live|archive-url=https://web.archive.org/web/20231120173518/https://www.nasa.gov/mission/sts-133/|archive-date=20 November 2023|access-date=1 September 2014|publisher=NASA}}

Russia's new primary research module Nauka docked in July 2021,{{Cite news|date=28 September 2011|title=Crewed spacecraft docked to ISS's module Nauka first time|url=https://tass.com/science/1343409|url-status=live|archive-url=https://web.archive.org/web/20230810145340/https://tass.com/science/1343409|archive-date=10 August 2023|access-date=11 October 2021|agency=TASS}} along with the European Robotic Arm which can relocate itself to different parts of the Russian modules of the station.{{Cite news|date=25 March 2019|title=Рогозин подтвердил, что на модуль "Наука" поставят баки от разгонного блока "Фрегат"|trans-title=Rogozin confirmed that the module 'Science' placed the tanks from the upper stage 'Frigate'|url=https://tass.ru/kosmos/6253886|url-status=live|archive-url=https://web.archive.org/web/20230810144639/https://tass.ru/kosmos/6253886|archive-date=10 August 2023|access-date=31 March 2019|agency=TASS|language=ru}} Russia's latest addition, the Prichal module, docked in November 2021.{{Cite press release|title=Новый модуль вошел в состав российского сегмента МКС|date=26 November 2021|publisher=Roscosmos|url=https://www.roscosmos.ru/33473/|language=ru|access-date=6 May 2022|url-status=dead|archive-url=https://web.archive.org/web/20211127013431/https://www.roscosmos.ru/33473/|archive-date=27 November 2021|trans-title=A new module has entered the composition of the Russian segment of the ISS}}

As of February 2025, nasa.gov states that there are 43 different modules and elements installed on the ISS. https://www.nasa.gov/international-space-station/international-space-station-assembly-elements/

The ISS functions as a modular space station, enabling the addition or removal of modules from its structure for increased adaptability.

File:ISS blueprint.png|Blueprint of ISS (as of 2018)

File:Iss after installation of all roll out solar arrays.jpg|Rendering of ISS (as of 2023)

Below is a diagram of major station components. The Unity node joins directly to the Destiny laboratory; for clarity, they are shown apart. Similar cases are also seen in other parts of the structure.

Key to box background colors:

• {{color box|#CCDDFF}} Pressurised component, accessible by the crew without using spacesuits
• {{color box|#B9E192}} Docking/berthing port, pressurized when a visiting spacecraft is present
• {{color box|#DCC5ED}} Airlock, to move people or material between pressurized and unpressurized environment
• {{color box|#FFCCCC}} Unpressurised station superstructure
• {{color box|#FFF4CC}} Unpressurised component
• {{color box|#D2691E}} Temporarily defunct or non-commissioned component
• {{color box|#808080}} Former, no longer installed component
• {{color box|#FFFFFF}} Future, not yet installed component

{{Main|Zarya (ISS module)}}

File:Zarya from STS-88.jpg]]

Zarya ({{Langx|ru|Заря|lit=Sunrise}}{{efn|"Zarya" has several meanings: "daybreak" or "dawn" (in the morning) or "afterglow", "evening glow" or "sunset" (in the evening), but NASA and Roscosmos translate it as "sunrise."{{Cite web |last=bryan |date=25 January 2016 |title=Image showing Zarya mockup at the NASA Johnson Space Center with the translation Sunrise |url=https://commons.wikimedia.org/wiki/File:Lyndon_B._Johnson_Space_Center_Johnson_Space_Center_JSC_NASA_Houston_Space_City_United_States_America_The_States_USA_US_(24560757054).jpg |access-date=20 November 2024 |website=Wikimedia Commons}}}}), also known as the Functional Cargo Block ({{Langx|ru|Функционально-грузовой блок|links=no}}), was the inaugural component of the ISS. Launched in 1998, it initially served as the ISS's power source, storage, propulsion, and guidance system. As the station has grown, Zarya's role has transitioned primarily to storage, both internally and in its external fuel tanks.{{Cite web|url=https://www.nasa.gov/international-space-station/zarya-module/|title=Zarya Module|publisher=NASA|access-date=19 April 2014|url-status=live|archive-url=https://web.archive.org/web/20231118134120/https://www.nasa.gov/international-space-station/zarya-module/|archive-date=18 November 2023}}

A descendant of the TKS spacecraft used in the Salyut programme, Zarya was built in Russia but is owned by the United States. Its name symbolizes the beginning of a new era of international space cooperation.{{Cite web|url=https://www.russianspaceweb.com/iss_enterprise.html|title=Russian Segment: Enterprise|last=Zak|first=Anatoly|date=15 October 2008|access-date=4 August 2012|url-status=live|archive-url=https://web.archive.org/web/20230811163146/https://www.russianspaceweb.com/iss_enterprise.html|archive-date=11 August 2023|website=RussianSpaceWeb}}

{{Main|Unity (ISS module)}}

File:ISS Unity module.jpg]]

Unity, also known as Node 1, is the inaugural U.S.-built component of the ISS.{{Cite web|title=NASA – NSSDCA – Spacecraft – Details|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1998-069F|url-status=live|archive-url=https://web.archive.org/web/20230423215409/https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1998-069F|archive-date=23 April 2023|access-date=6 May 2022|website=nssdc.gsfc.nasa.gov|publisher=NASA|id=1998-069F}}{{cite web|last=Loff|first=Sarah|date=15 November 2018|title=Unity|url=http://www.nasa.gov/mission_pages/station/structure/elements/unity|access-date=6 May 2022|website=NASA|archive-date=5 June 2022|archive-url=https://web.archive.org/web/20220605221424/https://www.nasa.gov/mission_pages/station/structure/elements/unity/|url-status=dead}} Serving as the connection between the Russian and U.S. segments, this cylindrical module features six Common Berthing Mechanism locations (forward, aft, port, starboard, zenith, and nadir) for attaching additional modules. Measuring {{convert|4.57|m}} in diameter and {{convert|5.47|m}} in length, Unity was constructed of steel by Boeing for NASA at the Marshall Space Flight Center in Huntsville, Alabama. It was the first of three connecting nodes – Unity, Harmony, and Tranquility – that forms the structural backbone of the U.S. segment of the ISS.{{Cite web|url=https://blogs.nasa.gov/sailing_with_nasa/2009/10/20/post_1256076937193/|title=ET-134's Mission,STS-130: Launching Tranquility|last=Roy|first=Steve|date=20 October 2009|publisher=NASA|access-date=23 November 2023|url-status=live|archive-url=https://web.archive.org/web/20230322123432/https://blogs.nasa.gov/sailing_with_nasa/2009/10/20/post_1256076937193/|archive-date=22 March 2023}}

{{Main|Zvezda (ISS module)}}

File:Zvezda (tight crop).jpg]]

Zvezda ({{Langx|ru|Звезда|lit=star|links=no}}) launched in July 2000, is the core of the Russian Orbital Segment of the ISS. Initially providing essential living quarters and life support systems, it enabled the first continuous human presence aboard the station. While additional modules have expanded the ISS's capabilities, Zvezda remains the command and control center for the Russian segment and it is where crews gather during emergencies.{{Cite AV media|url=https://www.youtube.com/watch?v=doN4t5NKW-k|title=Departing Space Station Commander Provides Tour of Orbital Laboratory|date=3 July 2015|last=Williams|first=Suni (presenter)|publisher=NASA|time=17.46–18.26|access-date=1 September 2019|medium=video|archive-date=14 August 2021|archive-url=https://web.archive.org/web/20210814155134/https://www.youtube.com/watch?v=doN4t5NKW-k|url-status=live}}{{cite web|last=Roylance|first=Frank D.|date=11 November 2000|title=Space station astronauts take shelter from solar radiation|url=https://www.baltimoresun.com/news/bs-xpm-2000-11-11-0011110386-story.html|access-date=1 September 2019|website=The Baltimore Sun|publisher=Tribune Publishing|archive-date=1 September 2019|archive-url=https://web.archive.org/web/20190901060300/https://www.baltimoresun.com/news/bs-xpm-2000-11-11-0011110386-story.html|url-status=dead}}{{cite web|last=Stofer|first=Kathryn|date=29 October 2013|title=Tuesday/Wednesday Solar Punch|url=https://www.nasa.gov/vision/universe/solarsystem/10.28Flare.html|access-date=1 September 2019|website=NASA|archive-date=2 December 2020|archive-url=https://web.archive.org/web/20201202225119/https://www.nasa.gov/vision/universe/solarsystem/10.28Flare.html|url-status=dead}}

A descendant of the Salyut programme's DOS spacecraft, Zvezda was built by RKK Energia and launched atop a Proton rocket.{{cite web|title=Service Module {{!}} RuSpace|url=http://suzymchale.com/ruspace/sm.html|access-date=10 November 2020|website=suzymchale.com|archive-date=21 September 2020|archive-url=https://web.archive.org/web/20200921234759/http://suzymchale.com/ruspace/sm.html|url-status=dead}}

{{Main|Destiny (ISS module)}}

File:ISS Destiny Lab.jpg

The Destiny laboratory is the primary research facility for U.S. experiments on the ISS. NASA's first permanent orbital research station since Skylab, the module was built by Boeing and launched aboard {{OV|104}} during STS-98. Attached to Unity over a period of five days in February 2001, Destiny has been a hub for scientific research ever since.{{Cite web|url=http://www.boeing.com/defense-space/space/spacestation/components/us_laboratory.html|title=Destiny Laboratory Module|last=Boeing|year=2008|publisher=Boeing|access-date=7 October 2008|url-status=live|archive-url=https://web.archive.org/web/20081011150013/http://www.boeing.com/defense-space/space/spacestation/components/us_laboratory.html|archive-date=11 October 2008}}{{Cite web|url=http://www.nasa.gov/mission_pages/station/structure/elements/destiny.html|title=U.S. Destiny Laboratory|year=2003|publisher=NASA|access-date=7 October 2008|url-status=dead|archive-url=https://web.archive.org/web/20070709153924/http://www.nasa.gov/mission_pages/station/structure/elements/destiny.html|archive-date=9 July 2007}}{{cite web|year=2001|title=STS-98|url=http://science.ksc.nasa.gov/shuttle/missions/sts-98/mission-sts-98.html|access-date=7 October 2008|publisher=NASA|archive-date=30 August 2013|archive-url=https://web.archive.org/web/20130830041616/http://science.ksc.nasa.gov/shuttle/missions/sts-98/mission-sts-98.html|url-status=dead}}

Within Destiny, astronauts conduct experiments in fields such as medicine, engineering, biotechnology, physics, materials science, and Earth science. Researchers worldwide benefit from these studies. The module also houses life support systems, including the Oxygen Generating System.{{cite web|url=http://www.nasaspaceflight.com/2007/07/oxygen-generating-system-activated-onboard-iss/|title=Oxygen Generating System activated onboard ISS|access-date=25 January 2010|author=Chris Bergin|publisher=NASASpaceflight.com|date=12 July 2007}}

{{Main|Quest Joint Airlock}}

File:Quest airlock exterior - STS-127.jpg

The Quest Joint Airlock enables extravehicular activities (EVAs) using either the U.S. Extravehicular Mobility Unit (EMU) or the Russian Orlan space suit.{{cite web|title=Quest Airlock|url=https://www.nasa.gov/international-space-station/quest-airlock/|publisher=NASA|access-date=24 November 2023|archive-url=https://web.archive.org/web/20231024152123/https://www.nasa.gov/international-space-station/quest-airlock/|archive-date=24 October 2023|url-status=live}}

Before its installation, conducting EVAs from the ISS was challenging due to a variety of system and design differences. Only the Orlan suit could be used from the Transfer Chamber on the Zvezda module (which was not a purpose-built airlock) and the EMU could only be used from the airlock on a visiting Space Shuttle, which could not accommodate the Orlan.{{cite tech report|last1=Stockman|first1=Bill|last2=Boyle|first2=Joe|last3=Bacon|first3=John|title=International Space Station Systems Engineering Case Study|url=https://apps.dtic.mil/sti/tr/pdf/ADA538763.pdf|publisher=United States Air Force|access-date=24 November 2023|archive-url=https://web.archive.org/web/20231124095002/https://apps.dtic.mil/sti/tr/pdf/ADA538763.pdf|archive-date=24 November 2023|pages=36–38|year=2010|url-status=live}}

Launched aboard {{OV|104}} during STS-104 in July 2001 and attached to the Unity module, Quest is a {{convert|20|ft|m|adj=mid|order=flip|-long}}, {{convert|13|ft|m|adj=mid|order=flip|-wide}} structure built by Boeing.{{cite web|last1=Uri|first1=John|title=Space Station 20th: STS-104 Brings Quest Joint Airlock to the Space Station|url=https://www.nasa.gov/history/space-station-20th-sts-104-brings-quest-joint-airlock-to-the-space-station/|publisher=NASA|access-date=24 November 2023|archive-url=https://web.archive.org/web/20231124093812/https://www.nasa.gov/history/space-station-20th-sts-104-brings-quest-joint-airlock-to-the-space-station/|archive-date=24 November 2023|date=14 July 2021|url-status=live}} It houses the crew airlock for astronaut egress, an equipment airlock for suit storage, and has facilities to accommodate astronauts during their overnight pre-breathe procedures to prevent decompression sickness.

The crew airlock, derived from the Space Shuttle, features essential equipment like lighting, handrails, and an Umbilical Interface Assembly (UIA) that provides life support and communication systems for up to two spacesuits simultaneously. These can be either two EMUs, two Orlan suits, or one of each design.

{{Main|Poisk (ISS module)}}

Poisk ({{Langx|ru|По́иск|lit=Search|links=no}}), also known as the Mini-Research Module 2 ({{Langx|ru|Малый исследовательский модуль 2|links=no}}), serves as both a secondary airlock on the Russian segment of the ISS and supports docking for Soyuz and Progress spacecraft, facilitates propellant transfers from the latter.{{cite web|date=10 May 2006|title=Pirs Docking Compartment|url=http://www.nasa.gov/mission_pages/station/structure/elements/pirs.html|access-date=28 March 2009|publisher=NASA|archive-date=25 October 2005|archive-url=https://web.archive.org/web/20051025154605/http://www.nasa.gov/mission_pages/station/structure/elements/pirs.html|url-status=dead}} Launched on 10 November 2009 attached to a modified Progress spacecraft, called Progress M-MIM2.{{Cite news|date=28 August 2009|title=August 28, 2009. S. P. Korolev RSC Energia, Korolev, Moscow region|url=http://www.energia.ru/eng/iss/mim1/photo_08-28.html|url-status=dead|archive-url=https://web.archive.org/web/20200921031747/https://www.energia.ru/eng/iss/mim1/photo_08-28.html|archive-date=21 September 2020|access-date=3 September 2009|publisher=RSC Energia}}{{Cite news|url=https://spaceflightnow.com/station/exp21/091110mrmlaunch/|title=Poisk launches to add new room for space station|last=Clark|first=Stephen|date=10 November 2009|access-date=11 November 2009|url-status=live|archive-url=https://web.archive.org/web/20230810132113/https://spaceflightnow.com/station/exp21/091110mrmlaunch/|archive-date=10 August 2023|work=Spaceflight Now}}

Poisk provides facilities to maintain Orlan spacesuits and is equipped with two inward-opening hatches, a design change from Mir, which encountered a dangerous situation caused by an outward-opening hatch that opened too quickly because of a small amount of air pressure remaining in the airlock.{{Cite web|url=https://www.russianspaceweb.com/mir_close_calls.html|title=Mir close calls|last=Zak|first=Anatoly|access-date=1 May 2012|url-status=live|archive-url=https://web.archive.org/web/20230811162132/https://www.russianspaceweb.com/mir_close_calls.html|archive-date=11 August 2023|website=RussianSpaceWeb}} Since the departure of Pirs in 2021, it's become the sole airlock on the Russian segment.

{{Main|Harmony (ISS module)}}

File:Node 2 - STS-134.jpg faces the camera. The nadir and zenith locations are open.]]

Harmony, or Node 2, is the central connecting hub of the US segment of the ISS, linking the U.S., European, and Japanese laboratory modules. It's also been called the "utility hub" of the ISS as it provides essential power, data, and life support systems. The module also houses sleeping quarters for four crew members.{{Cite AV media|url=https://www.youtube.com/watch?v=ukws3oLMDc8|archive-url=https://ghostarchive.org/varchive/youtube/20211211/ukws3oLMDc8|archive-date=11 December 2021|url-status=live|title=Station Tour: Harmony, Tranquility, Unity|date=19 May 2013|last=Williams|first=Suni (presenter)|publisher=NASA|time=0.06–0.35|access-date=31 August 2019|quote=So this is Node 2 ... this is where four out of six of us sleep.|medium=video}}{{cbignore}}

Launched on 23 October 2007 aboard {{OV|103}} on STS-120,{{cite web|last=NASA|date=23 October 2007|title=STS-120 MCC Status Report #01|url=http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts120/news/STS-120-01.html|publisher=NASA|access-date=22 September 2019|archive-date=28 October 2007|archive-url=https://web.archive.org/web/20071028131000/http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts120/news/STS-120-01.html|url-status=dead}}{{Cite news|url=https://www.latimes.com/archives/la-xpm-2007-oct-24-sci-shuttle24-story.html|title=Shuttle embarks on busy mission|last=Johnson, Jr.|first=John|date=24 October 2007|access-date=23 October 2007|url-status=live|archive-url=https://web.archive.org/web/20230812222654/https://www.latimes.com/archives/la-xpm-2007-oct-24-sci-shuttle24-story.html|archive-date=12 August 2023|work=Los Angeles Times}} Harmony was initially attached to the Unity{{Cite news|url=https://www.cbsnews.com/network/news/space/120/STS-120_Archive.html|title=Harmony module pulled from cargo bay|last=Harwood|first=William|date=26 October 2007|access-date=26 October 2007|url-status=live|archive-url=https://web.archive.org/web/20210917130622/http://www.cbsnews.com/network/news/space/120/STS-120_Archive.html|archive-date=17 September 2021|publisher=CBS News}}{{Cite news|url=https://www.nytimes.com/2007/10/26/science/26cnd-shuttle.html|url-access=subscription|title=New Room Added to Space Station|last=Schwartz|first=John|date=26 October 2007|access-date=26 October 2007|url-status=live|archive-url=https://web.archive.org/web/20230811162928/https://www.nytimes.com/2007/10/26/science/26cnd-shuttle.html|archive-date=11 August 2023|work=The New York Times}} before being relocated to its permanent position at the front of the Destiny laboratory on 14 November 2007.{{cite web|last=NASA|year=2007|title=PMA-3 Relocation|url=http://www.nasa.gov/mission_pages/station/expeditions/expedition15/pma3move.html|access-date=28 September 2007|publisher=NASA|archive-date=12 October 2007|archive-url=https://web.archive.org/web/20071012235655/http://www.nasa.gov/mission_pages/station/expeditions/expedition15/pma3move.html|url-status=dead}} This expansion added significant living space to the ISS, marking a key milestone in the construction of the U.S. segment.

{{Main|Tranquility (ISS module)}}

File:Node 3 - Isolated view.jpg

Tranquility, also known as Node 3, is a module of the ISS. It contains environmental control systems, life support systems, a toilet, exercise equipment, and an observation cupola.

The European Space Agency and the Italian Space Agency had Tranquility manufactured by Thales Alenia Space. A ceremony on 20 November 2009 transferred ownership of the module to NASA.{{cite web|date=23 October 2010|title=NASA – NASA Receives Tranquility|url=http://www.nasa.gov/mission_pages/station/behindscenes/tranquility_transfer.html|access-date=12 August 2013|publisher=Nasa.gov|archive-date=11 August 2023|archive-url=https://web.archive.org/web/20230811174634/https://www.nasa.gov/mission_pages/station/behindscenes/tranquility_transfer.html|url-status=dead}} On 8 February 2010, NASA launched the module on the Space Shuttle's STS-130 mission.

{{Main|Columbus (ISS module)}}

File:Columbus module - cropped.jpg

Columbus is a science laboratory that is part of the ISS and is the largest single contribution to the station made by the European Space Agency.

Like the Harmony and Tranquility modules, the Columbus laboratory was constructed in Turin, Italy by Thales Alenia Space. The functional equipment and software of the lab was designed by EADS in Bremen, Germany. It was also integrated in Bremen before being flown to the Kennedy Space Center in Florida in an Airbus Beluga jet. It was launched aboard Space Shuttle Atlantis on 7 February 2008, on flight STS-122. It is designed for ten years of operation. The module is controlled by the Columbus Control Centre, located at the German Space Operations Center, part of the German Aerospace Center in Oberpfaffenhofen near Munich, Germany.

The European Space Agency has spent €1.4 billion (about US$1.6 billion) on building Columbus, including the experiments it carries and the ground control infrastructure necessary to operate them.{{Cite news|url=http://spaceflightnow.com/shuttle/sts122/080211fd5/index3.html|title=Station arm pulls Columbus module from cargo bay|last=Harwood|first=William|date=11 February 2008|access-date=7 August 2009|url-status=live|archive-url=https://web.archive.org/web/20160507224754/http://spaceflightnow.com/shuttle/sts122/080211fd5/index3.html|archive-date=7 May 2016|work=Spaceflight Now}}

{{Main|Kibō (ISS module)}}

File:Japanese Experiment Module exterior - cropped.jpg

{{Nihongo|Kibō|きぼう||{{lit|hope}}|lead=yes}}, also known as the Japanese Experiment Module, is Japan's research facility on the ISS. It is the largest single module on the ISS, consisting of a pressurized lab, an exposed facility for conducting experiments in the space environment, two storage compartments, and a robotic arm. Attached to the Harmony module, Kibō was assembled in space over three Space Shuttle missions: STS-123, STS-124 and STS-127.{{Cite news|url=https://www.japantimes.co.jp/news/2009/06/30/reference/japan-a-low-key-player-in-space-race/|url-access=subscription|title=Japan a low-key player in space race|last=Kamiya|first=Setsuko|date=30 June 2009|work=The Japan Times|page=3|url-status=live|archive-url=https://web.archive.org/web/20130813092804/http://www.japantimes.co.jp/news/2009/06/30/reference/japan-a-low-key-player-in-space-race/#.Ugn8K-t_pqY|archive-date=13 August 2013}}

{{Main|Cupola (ISS module)}}

File:STS130 cupola view1.jpg

The Cupola is an ESA-built observatory module of the ISS. Its name derives from the Italian word {{lang|it|cupola}}, which means "dome". Its seven windows are used to conduct experiments, dockings and observations of Earth. It was launched aboard Space Shuttle mission STS-130 on 8 February 2010 and attached to the Tranquility (Node 3) module. With the Cupola attached, ISS assembly reached 85 per cent completion. The Cupola{{'s}} central window has a diameter of {{convert|80|cm|abbr=on}}.{{Cite web|url=http://www.thalesaleniaspace-issmodules.com/cupola|title=Thales Alenia Space and ISS modules – Cupola: a window over the Earth|date=26 July 2010|url-status=dead|archive-url=https://web.archive.org/web/20100726075315/http://www.thalesaleniaspace-issmodules.com/cupola|archive-date=26 July 2010}}

{{Main|Rassvet (ISS module)}}

File:STS132 Mini-Research Module-1.jpg

Rassvet ({{Langx|ru|Рассвет|lit=first light|links=no}}), also known as the Mini-Research Module 1 ({{Langx|ru|Малый исследовательский модуль 1|links=no}}) and formerly known as the Docking Cargo Module is primarily used for cargo storage and as a docking port for visiting spacecraft on the Russian segment of the ISS. Rassvet replaced the cancelled Docking and Storage Module and used a design largely based on the Mir Docking Module built in 1995.

Rassvet was delivered in on 14 May 2010 {{OV|104}} on STS-132 in exchange for the Russian Proton delivery of the US-funded Zarya module in 1998.{{Cite news|url=https://www.nasaspaceflight.com/2009/04/sts-132-prcb-baselines-mission-to-deliver-russias-mrm-1/|title=STS-132: PRCB baselines Atlantis' mission to deliver Russia's MRM-1|last=Gebhardt|first=Chris|date=9 April 2009|access-date=12 November 2009|url-status=live|archive-url=https://web.archive.org/web/20230412103414/https://www.nasaspaceflight.com/2009/04/sts-132-prcb-baselines-mission-to-deliver-russias-mrm-1/|archive-date=12 April 2023|work=NASASpaceFlight.com}} Rassvet was attached to Zarya shortly thereafter.{{Cite web|url=http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts132/news/STS-132-09.html|title=STS-132 MCC Status Report #09|date=18 May 2010|publisher=NASA|access-date=7 July 2010|url-status=dead|archive-url=https://web.archive.org/web/20130408013431/http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts132/news/STS-132-09.html|archive-date=8 April 2013}} {{PD-notice}}

{{Main|Leonardo (ISS module)}}The Leonardo Permanent Multipurpose Module (PMM) is a module of the International Space Station. It was flown into space aboard the Space Shuttle on STS-133 on 24 February 2011 and installed on 1 March. Leonardo is primarily used for storage of spares, supplies and waste on the ISS, which was until then stored in many different places within the space station. It is also the personal hygiene area for the astronauts who live in the US Orbital Segment. The Leonardo PMM was a Multi-Purpose Logistics Module (MPLM) before 2011, but was modified into its current configuration. It was formerly one of two MPLM used for bringing cargo to and from the ISS with the Space Shuttle. The module was named for Italian polymath Leonardo da Vinci.

File:BEAM module expansion series.jpg

The Bigelow Expandable Activity Module (BEAM) is an experimental expandable space station module developed by Bigelow Aerospace, under contract to NASA, for testing as a temporary module on the International Space Station (ISS) from 2016 to at least 2020. It arrived at the ISS on 10 April 2016,{{Cite news|url=https://www.space.com/32528-spacex-dragon-delivers-inflatable-room-space-station.html|title=SpaceX Dragon Arrives at Space Station, Delivers Inflatable Room Prototype|last=Pearlman|first=Robert|date=10 April 2016|access-date=11 April 2016|url-status=live|archive-url=https://web.archive.org/web/20230611082951/https://www.space.com/32528-spacex-dragon-delivers-inflatable-room-space-station.html|archive-date=11 June 2023|work=Space.com}} was berthed to the station on 16 April at Tranquility Node 3, and was expanded and pressurized on 28 May 2016. In December 2021, Bigelow Aerospace conveyed ownership of the module to NASA, as a result of Bigelow's cessation of activity.{{Cite web|last=Foust|first=Jeff|date=21 January 2022|title=Bigelow Aerospace transfers BEAM space station module to NASA|url=https://spacenews.com/bigelow-aerospace-transfers-beam-space-station-module-to-nasa/|access-date=13 February 2024|website=SpaceNews}}

The International Docking Adapter (IDA) is a spacecraft docking system adapter developed to convert APAS-95 to the NASA Docking System (NDS). An IDA is placed on each of the ISS's two open Pressurized Mating Adapters (PMAs), both of which are connected to the Harmony module.

Two International Docking Adapters are currently installed aboard the Station. Originally, IDA-1 was planned to be installed on PMA-2, located at Harmony's forward port, and IDA-2 would be installed on PMA-3 at Harmony's zenith. After IDA 1 was destroyed in a launch incident, IDA-2 was installed on PMA-2 on 19 August 2016,{{Cite news|url=https://spaceflightnow.com/2016/08/19/spacewalkers-attach-new-port-to-space-station-for-commercial-spacecraft/|title=Spacewalkers attach docking adapter to space station for commercial vehicles|last=Harwood|first=William|date=19 August 2016|access-date=24 January 2021|url-status=live|archive-url=https://web.archive.org/web/20230810145126/https://spaceflightnow.com/2016/08/19/spacewalkers-attach-new-port-to-space-station-for-commercial-spacecraft/|archive-date=10 August 2023|work=Spaceflight Now}} while IDA-3 was later installed on PMA-3 on 21 August 2019.{{Cite news|last=Garcia|first=Mark|date=21 August 2019|title=Spacewalkers Complete Installation of Second Commercial Docking Port|work=NASA Space Station|url=https://blogs.nasa.gov/spacestation/2019/08/21/spacewalkers-complete-installation-of-second-commercial-docking-port/|access-date=24 January 2021|archive-date=2 June 2020|archive-url=https://web.archive.org/web/20200602183325/https://blogs.nasa.gov/spacestation/2019/08/21/spacewalkers-complete-installation-of-second-commercial-docking-port/|url-status=dead}}

{{Main|Nanoracks Bishop Airlock}}

File:ISS-64 NanoRacks Bishop airlock after installation.jpg

The NanoRacks Bishop Airlock Module is a commercially funded airlock module launched to the ISS on SpaceX CRS-21 on 6 December 2020.{{Cite press release|url=https://www.thalesgroup.com/en/worldwide/space/press-release/thales-alenia-space-reaches-key-milestone-nanoracks-airlock-module|title=Thales Alenia Space reaches key milestone for NanoRacks' airlock module|date=20 March 2019|publisher=Thales Alenia Space|location=Turin, Italy|access-date=22 August 2019|url-status=live|archive-url=https://web.archive.org/web/20230810130710/https://www.thalesgroup.com/en/worldwide/space/press-release/thales-alenia-space-reaches-key-milestone-nanoracks-airlock-module|archive-date=10 August 2023}}{{Cite news|url=https://spaceflightnow.com/2019/08/02/spacex-to-begin-flights-under-new-cargo-resupply-contract-next-year/|title=SpaceX to begin flights under new cargo resupply contract next year|last=Clark|first=Stephen|date=2 August 2019|access-date=22 August 2019|url-status=live|archive-url=https://web.archive.org/web/20230602175020/https://spaceflightnow.com/2019/08/02/spacex-to-begin-flights-under-new-cargo-resupply-contract-next-year/|archive-date=2 June 2023|work=Spaceflight Now}} The module was built by NanoRacks, Thales Alenia Space, and Boeing.{{Cite press release|url=https://nanoracks.com/nanoracks-boeing-first-commercial-airlock-module-on-iss/|title=NanoRacks, Boeing to Build First Commercial ISS Airlock Module|date=6 February 2017|publisher=NanoRacks|access-date=22 August 2019|url-status=live|archive-url=https://web.archive.org/web/20230811163145/https://nanoracks.com/nanoracks-boeing-first-commercial-airlock-module-on-iss/|archive-date=11 August 2023}} It will be used to deploy CubeSats, small satellites, and other external payloads for NASA, CASIS, and other commercial and governmental customers.{{cite web|last=Garcia|first=Mark|date=6 February 2017|title=Progress Underway for First Commercial Airlock on Space Station|url=https://www.nasa.gov/feature/progress-underway-for-first-commercial-airlock-on-space-station|access-date=22 August 2019|publisher=NASA|archive-date=12 November 2020|archive-url=https://web.archive.org/web/20201112004837/https://www.nasa.gov/feature/progress-underway-for-first-commercial-airlock-on-space-station/|url-status=dead}}

File:Russian Spacewalkers dwarfed by the Nauka and Prichal modules 2 (cropped).jpg

{{Main|Nauka (ISS module)}}

Nauka ({{Langx|ru|Наука|lit=Science|links=no}}), also known as the Multipurpose Laboratory Module, Upgrade ({{Langx|ru|Многоцелевой лабораторный модуль, усоверше́нствованный|links=no}}), is a Roscosmos-funded component of the ISS that was launched on 21 July 2021, 14:58 UTC. In the original ISS plans, Nauka was to use the location of the Docking and Stowage Module (DSM), but the DSM was later replaced by the Rassvet module and moved to Zarya{{'}}s nadir port. Nauka was successfully docked to Zvezda{{'}}s nadir port on 29 July 2021, 13:29 UTC, replacing the Pirs module.

It had a temporary docking adapter on its nadir port for crewed and uncrewed missions until Prichal arrival, where just before its arrival it was removed by a departing Progress spacecraft.{{Cite web|url=http://russianspaceweb.com/progress-ms-17.html#redocking|title=Progress MS-17 lifts off to prepare Prichal module arrival|last=Zak|first=Anatoly|date=9 February 2021|access-date=21 October 2021|url-status=live|archive-url=https://web.archive.org/web/20230811171304/https://russianspaceweb.com/progress-ms-17.html#redocking|archive-date=11 August 2023|website=RussianSpaceWeb}}

{{Main|Prichal (ISS module)}}

Prichal ({{Langx|ru|Причал|lit=pier|links=no}}) is a {{convert|4|t|lb|adj=on}} spherical module that serves as a docking hub for the Russian segment of the ISS. Launched in November 2021, Prichal provides additional docking ports for Soyuz and Progress spacecraft, as well as potential future modules. Prichal features six docking ports: forward, aft, port, starboard, zenith, and nadir. One of these ports, equipped with an active hybrid docking system, enabled it to dock with the Nauka module. The remaining five ports are passive hybrids, allowing for docking of Soyuz, Progress, and heavier modules, as well as future spacecraft with modified docking systems. As of 2024, the forward, aft, port and starboard docking ports remain covered. Prichal was initially intended to be an element of the now canceled Orbital Piloted Assembly and Experiment Complex.{{Cite web|url=https://www.russianspaceweb.com/iss_node.html#2020|title=Prichal Node Module, UM|last=Zak|first=Anatoly|date=22 June 2020|access-date=23 June 2020|url-status=live|archive-url=https://web.archive.org/web/20231120175425/https://www.russianspaceweb.com/iss_node.html#2020|archive-date=20 November 2023|website=RussianSpaceWeb}}{{Cite news|url=https://spaceflightnow.com/2019/07/25/new-docking-port-spacesuit-and-supplies-en-route-to-space-station/|title=New docking port, spacesuit and supplies en route to space station|last=Clark|first=Stephen|date=25 July 2019|access-date=17 August 2019|url-status=live|archive-url=https://web.archive.org/web/20230810130845/https://spaceflightnow.com/2019/07/25/new-docking-port-spacesuit-and-supplies-en-route-to-space-station/|archive-date=10 August 2023|work=Spaceflight Now}}{{Cite press release|url=http://www.energia.ru/en/news/news-2011/news_01-13.html|title=News January 13, 2011|date=13 January 2011|publisher=Energia|access-date=8 October 2011|url-status=dead|archive-url=https://web.archive.org/web/20170702225123/http://www.energia.ru/en/news/news-2011/news_01-13.html|archive-date=2 July 2017}}{{Cite news|url=https://www.nasaspaceflight.com/2020/08/nauka-arrives-baikonur-final-preps/|title=Russia's Nauka ISS module arrives at Baikonur for final launch preparations|last=Atkinson|first=Ian|date=19 August 2020|access-date=20 August 2020|url-status=live|archive-url=https://web.archive.org/web/20230810132018/https://www.nasaspaceflight.com/2020/08/nauka-arrives-baikonur-final-preps/|archive-date=10 August 2023|work=NASASpaceFlight.com}}

{{multiple image

| align = right

| total_width = 400

| image1 = Truss breakdown.png

| caption1 = ISS Truss Components breakdown showing Trusses and all ORUs in situ

| image2 = STS-116 spacewalk 1.jpg

| caption2 = Construction of the Integrated Truss Structure over New Zealand

}}

The ISS has a large number of external components that do not require pressurisation. The largest of these is the Integrated Truss Structure (ITS), to which the station's main solar arrays and thermal radiators are mounted.{{Cite web|url=http://www.nasa.gov/mission_pages/station/behindscenes/truss_segment.html|title=Spread Your Wings, It's Time to Fly|date=26 July 2006|publisher=NASA|access-date=21 September 2006|url-status=dead|archive-url=https://web.archive.org/web/20230111135544/http://www.nasa.gov/mission_pages/station/behindscenes/truss_segment.html|archive-date=11 January 2023}} {{PD-notice}} The ITS consists of ten separate segments forming a structure {{convert|108.5|m}} long.

The station was intended to have several smaller external components, such as six robotic arms, three External Stowage Platforms (ESPs) and four ExPRESS Logistics Carriers (ELCs).{{Cite web|url=http://www.nasa.gov/mission_pages/station/structure/iss_manifest.html|title=Consolidated Launch Manifest|year=2008|publisher=NASA|access-date=8 July 2008|url-status=dead|archive-url=https://web.archive.org/web/20090307191348/http://www.nasa.gov/mission_pages/station/structure/iss_manifest.html|archive-date=7 March 2009}} {{PD-notice}}{{Cite web|url=http://www.nasa.gov/centers/marshall/news/background/facts/expressrack.html|title=EXPRESS Racks 1 and 2 fact sheet|date=1 February 2001|id=FS-2001-02-34-MSFC|access-date=4 October 2009|url-status=dead|archive-url=https://web.archive.org/web/20080829173441/http://www.nasa.gov:80/centers/marshall/news/background/facts/expressrack.html|archive-date=29 August 2008}} {{PD-notice}} While these platforms allow experiments (including MISSE, the STP-H3 and the Robotic Refueling Mission) to be deployed and conducted in the vacuum of space by providing electricity and processing experimental data locally, their primary function is to store spare Orbital Replacement Units (ORUs). ORUs are parts that can be replaced when they fail or pass their design life, including pumps, storage tanks, antennas, and battery units. Such units are replaced either by astronauts during EVA or by robotic arms.{{Cite news|url=https://www.nasaspaceflight.com/2011/12/soyuz-tma-03m-docks-iss-returns-station-six-crewmembers-future-ops/|title=Soyuz TMA-03M docks to ISS, returns station to six crewmembers for future ops|date=23 December 2011|access-date=1 May 2012|url-status=live|archive-url=https://web.archive.org/web/20230811170248/https://www.nasaspaceflight.com/2011/12/soyuz-tma-03m-docks-iss-returns-station-six-crewmembers-future-ops/|archive-date=11 August 2023|work=NASASpaceFlight.com}} Several shuttle missions were dedicated to the delivery of ORUs, including STS-129,{{Cite web|url=http://www.nasa.gov/centers/johnson/pdf/404493main_EVA_129_F_E1.pdf|title=EVA Checklist: STS-129 Flight Supplement|last=Welsch|first=L. D.|date=30 October 2009|publisher=NASA|access-date=9 July 2011|url-status=dead|archive-url=https://web.archive.org/web/20111129141620/http://www.nasa.gov/centers/johnson/pdf/404493main_EVA_129_F_E1.pdf|archive-date=29 November 2011}} {{PD-notice}} STS-133{{Cite web|url=https://www.nasa.gov/wp-content/uploads/2023/05/491387main-sts-133-press-kit.pdf|title=Space Shuttle Mission: STS-133 Press Kit|date=February 2011|publisher=NASA|access-date=9 July 2011|url-status=live|archive-url=https://web.archive.org/web/20231012174024/https://www.nasa.gov/wp-content/uploads/2023/05/491387main-sts-133-press-kit.pdf|archive-date=12 October 2023}} {{PD-notice}} and STS-134.{{Cite web|url=https://www.nasa.gov/pdf/538352main_sts134_presskit_508.pdf|title=Space Shuttle Mission: STS-134|date=April 2011|publisher=NASA|access-date=9 July 2011|url-status=dead|archive-url=https://web.archive.org/web/20181226120713/https://www.nasa.gov/pdf/538352main_sts134_presskit_508.pdf|archive-date=26 December 2018}} {{PD-notice}} {{as of|2011|01}}, only one other mode of transportation of ORUs had been used{{snd}}the Japanese cargo vessel HTV-2{{snd}}which delivered an FHRC and CTC-2 via its Exposed Pallet (EP).{{Cite web|url=https://iss.jaxa.jp/en/htv/mission/htv-2/library/presskit/htv2_presskit_en.pdf|title=HTV2: Mission Press Kit|date=20 January 2011|publisher=Japan Aerospace Exploration Agency|url-status=live|archive-url=https://web.archive.org/web/20230811163142/https://iss.jaxa.jp/en/htv/mission/htv-2/library/presskit/htv2_presskit_en.pdf|archive-date=11 August 2023}}{{update after|2013|1 |28}}

There are also smaller exposure facilities mounted directly to laboratory modules; the Kibō Exposed Facility serves as an external "porch" for the Kibō complex,{{cite web|date=29 August 2008|title=Exposed Facility:About Kibo|url=http://kibo.jaxa.jp/en/about/kibo/jef/|url-status=dead|archive-url=https://web.archive.org/web/20090803102352/http://kibo.jaxa.jp/en/about/kibo/jef/|archive-date=3 August 2009|access-date=9 October 2009|publisher=JAXA}} and a facility on the European Columbus laboratory provides power and data connections for experiments such as the European Technology Exposure Facility{{Cite web|url=http://www.nasa.gov/mission_pages/station/science/experiments/EuTEF.html|title=NASA–European Technology Exposure Facility (EuTEF)|date=6 October 2008|publisher=NASA|access-date=28 February 2009|url-status=dead|archive-url=https://web.archive.org/web/20081019013911/http://www.nasa.gov/mission_pages/station/science/experiments/EuTEF.html|archive-date=19 October 2008}} {{PD-notice}}{{Cite web|url=https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Columbus/European_Technology_Exposure_Facility_EuTEF|title=European Technology Exposure Facility (EuTEF)|date=13 January 2009|publisher=European Space Agency|access-date=28 February 2009|url-status=live|archive-url=https://web.archive.org/web/20230812214202/https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Columbus/European_Technology_Exposure_Facility_EuTEF|archive-date=12 August 2023}} and the Atomic Clock Ensemble in Space.{{cite web|title=Atomic Clock Ensemble in Space (ACES)|url=http://www.esa.int/SPECIALS/HSF_Research/SEMJSK0YDUF_0.html|url-status=dead|archive-url=https://web.archive.org/web/20090609110757/http://www.esa.int/SPECIALS/HSF_Research/SEMJSK0YDUF_0.html|archive-date=9 June 2009|access-date=9 October 2009|publisher=ESA}} A remote sensing instrument, SAGE III-ISS, was delivered to the station in February 2017 aboard CRS-10,{{Cite news|url=https://www.nasaspaceflight.com/2017/03/spacex-dragon-experiments-busy-science-period/|title=SpaceX science – Dragon delivers experiments for busy science period|last=Gebhardt|first=Chris|date=10 March 2017|access-date=11 January 2019|url-status=live|archive-url=https://web.archive.org/web/20230810132955/https://www.nasaspaceflight.com/2017/03/spacex-dragon-experiments-busy-science-period/|archive-date=10 August 2023|work=NASASpaceFlight.com}} and the NICER experiment was delivered aboard CRS-11 in June 2017.{{Cite news|url=https://www.nasaspaceflight.com/2017/06/spacex-falcon-9-crs-11-dragon-iss-100th-39a/|title=Falcon 9 launches with CRS-11 Dragon on 100th 39A launch|last=Graham|first=William|date=3 June 2017|access-date=11 January 2019|url-status=live|archive-url=https://web.archive.org/web/20230810145605/https://www.nasaspaceflight.com/2017/06/spacex-falcon-9-crs-11-dragon-iss-100th-39a/|archive-date=10 August 2023|work=NASASpaceFlight.com}} The largest scientific payload externally mounted to the ISS is the Alpha Magnetic Spectrometer (AMS), a particle physics experiment launched on STS-134 in May 2011, and mounted externally on the ITS. The AMS measures cosmic rays to look for evidence of dark matter and antimatter.{{Cite web|url=http://ams.cern.ch/|title=The Alpha Magnetic Spectrometer Experiment|date=21 January 2009|publisher=CERN|access-date=6 March 2009|url-status=live|archive-url=https://web.archive.org/web/20230811162236/https://ams.cern.ch/|archive-date=11 August 2023}}{{Cite news|url=https://www.nasaspaceflight.com/2013/04/endeavours-legacy-ams-02-proving-value/|title=Endeavour's ongoing legacy: AMS-02 proving its value|last=Bergin|first=Chris|date=4 April 2013|access-date=11 January 2019|url-status=live|archive-url=https://web.archive.org/web/20230810130623/https://www.nasaspaceflight.com/2013/04/endeavours-legacy-ams-02-proving-value/|archive-date=10 August 2023|work=NASASpaceFlight.com}}

The commercial Bartolomeo External Payload Hosting Platform, manufactured by Airbus, was launched on 6 March 2020 aboard CRS-20 and attached to the European Columbus module. It will provide an additional 12 external payload slots, supplementing the eight on the ExPRESS Logistics Carriers, ten on Kibō, and four on Columbus. The system is designed to be robotically serviced and will require no astronaut intervention. It is named after Christopher Columbus's younger brother.{{Cite news|url=https://www.spacedaily.com/reports/ESA_and_Airbus_sign_partnership_agreement_for_new_ISS_commercial_payload_platform_Bartolomeo_999.html|title=ESA and Airbus sign partnership agreement for new ISS commercial payload platform Bartolomeo|date=9 February 2018|access-date=10 February 2018|url-status=live|archive-url=https://web.archive.org/web/20230811172013/https://www.spacedaily.com/reports/ESA_and_Airbus_sign_partnership_agreement_for_new_ISS_commercial_payload_platform_Bartolomeo_999.html|archive-date=11 August 2023|work=SpaceDaily}}{{Cite news|url=https://www.aerospace-technology.com/news/airbus-esa-partner-bartolomeo-platform/|title=Airbus and ESA to partner on Bartolomeo platform|date=8 February 2018|access-date=10 February 2018|url-status=live|archive-url=https://web.archive.org/web/20230810145538/https://www.aerospace-technology.com/news/airbus-esa-partner-bartolomeo-platform/|archive-date=10 August 2023|work=Aerospace Technology}}{{Cite web|url=https://www.eoportal.org/satellite-missions/iss-bartolomeo|title=ISS: Bartolomeo|date=26 October 2016|publisher=European Space Agency|access-date=10 February 2018|url-status=live|archive-url=https://web.archive.org/web/20230812204548/https://www.eoportal.org/satellite-missions/iss-bartolomeo|archive-date=12 August 2023|website=eoPortal}}

{{multiple image

| align = right

| total_width = 400

| image1 = MRM1 Rassvet.png

| caption1 = MLM outfittings on Rassvet

| image2 = ISS-65 Nauka and Soyuz MS-18 docked to the International Space Station (1).jpg

| caption2 = A wide-angle view of the new module (behind Rassvet) attached to the ROS as seen from the cupola}}

In May 2010, equipment for Nauka was launched on STS-132 (as part of an agreement with NASA) and delivered by Space Shuttle Atlantis. Weighing 1.4 metric tons, the equipment was attached to the outside of Rassvet (MRM-1). It included a spare elbow joint for the European Robotic Arm (ERA) (which was launched with Nauka) and an ERA-portable workpost used during EVAs, as well as RTOd add-on heat radiator and internal hardware alongside the pressurized experiment airlock.{{Cite web|url=https://www.roscosmos.ru/31395/|title=Многоцелевой лабораторный модуль "Наука"|trans-title=Multipurpose Laboratory Module 'Nauka'|publisher=Roscosmos|language=ru|access-date=14 July 2021|url-status=dead|archive-url=https://web.archive.org/web/20210714161136/https://www.roscosmos.ru/31395/|archive-date=14 July 2021}}

The RTOd radiator adds additional cooling capability to Nauka, which enables the module to host more scientific experiments.

The ERA was used to remove the RTOd radiator from Rassvet and transferred over to Nauka during VKD-56 spacewalk. Later it was activated and fully deployed on VKD-58 spacewalk.{{Cite web|url=https://blogs.nasa.gov/spacestation/2023/05/12/cosmonauts-deploy-radiator-and-complete-spacewalk/|title=Cosmonauts Deploy Radiator and Complete Spacewalk|last=Garcia|first=Mark|date=12 May 2023|publisher=NASA|access-date=12 May 2023|url-status=live|archive-url=https://web.archive.org/web/20230731062433/https://blogs.nasa.gov/spacestation/2023/05/12/cosmonauts-deploy-radiator-and-complete-spacewalk/|archive-date=31 July 2023|website=NASA Blogs}} This process took several months. A portable work platform was also transferred over in August 2023 during VKD-60 spacewalk, which can attach to the end of the ERA to allow cosmonauts to "ride" on the end of the arm during spacewalks.{{Cite web|url=https://esamultimedia.esa.int/docs/science/ERA_brochure_EN.pdf|title=European Robotic Arm Brochure|publisher=European Space Agency|page=9|url-status=live|archive-url=https://web.archive.org/web/20230810130647/https://esamultimedia.esa.int/docs/science/ERA_brochure_EN.pdf|archive-date=10 August 2023}}{{Cite news|url=https://spaceflightnow.com/2023/08/09/live-coverage-russian-cosmonauts-make-spacewalk-at-international-space-station/|title=Russian cosmonauts make spacewalk at International Space Station|last=Harwood|first=William|date=9 August 2023|access-date=10 August 2023|url-status=live|archive-url=https://web.archive.org/web/20230812094606/https://spaceflightnow.com/2023/08/09/live-coverage-russian-cosmonauts-make-spacewalk-at-international-space-station/|archive-date=12 August 2023|work=Spaceflight Now}} However, even after several months of outfitting EVAs and RTOd heat radiator installation, six months later, the RTOd radiator malfunctioned before active use of Nauka (the purpose of RTOd installation is to radiate heat from Nauka experiments). The malfunction, a leak, rendered the RTOd radiator unusable for Nauka. This is the third ISS radiator leak after Soyuz MS-22 and Progress MS-21 radiator leaks. If a spare RTOd is not available, Nauka experiments will have to rely on Nauka's main launch radiator and the module could never be used to its full capacity.{{Cite news|url=https://spaceflightnow.com/2023/10/09/leak-detected-onboard-russian-segment-of-international-space-station/|title=Russian space station laboratory module appears to spring coolant leak – Spaceflight Now|date=9 October 2023|access-date=10 October 2023|url-status=live|archive-url=https://web.archive.org/web/20231014232548/https://spaceflightnow.com/2023/10/09/leak-detected-onboard-russian-segment-of-international-space-station/|archive-date=14 October 2023|work=Spaceflight Now}}{{Cite web|title=Госкорпорация "Роскосмос"|url=https://t.me/roscosmos_gk/11130|access-date=10 October 2023|website=Telegram|language=ru|archive-date=11 November 2023|archive-url=https://web.archive.org/web/20231111001124/https://t.me/roscosmos_gk/11130|url-status=live}}

Another MLM outfitting is a 4 segment external payload interface called means of attachment of large payloads (Sredstva Krepleniya Krupnogabaritnykh Obyektov, SKKO).{{Cite web|title=Sredstva Krepleniya Krupnogabaritnykh Obyektov, SKKO|url=https://forum.nasaspaceflight.com/index.php?action=pm;f=inbox;l=-1;done=sent|url-access=subscription|language=ru|access-date=4 April 2022|archive-date=6 July 2022|archive-url=https://web.archive.org/web/20220706041946/https://forum.nasaspaceflight.com/index.php?action=pm;f=inbox;l=-1;done=sent|url-status=live}} Delivered in two parts to Nauka by Progress MS-18 (LCCS part) and Progress MS-21 (SCCCS part) as part of the module activation outfitting process.{{Cite web|title=The Russian Nauka/Multipurpose Laboratory Module (MLM) General Thread|url=https://forum.nasaspaceflight.com/index.php?topic=23444.msg2419522#msg2419522|access-date=15 October 2022|website=forum.nasaspaceflight.com|archive-date=15 October 2022|archive-url=https://web.archive.org/web/20221015041008/https://forum.nasaspaceflight.com/index.php?topic=23444.msg2419522#msg2419522|url-status=live}}{{Cite web|title=Schedule of ISS flight events (part 2)|url=https://forum.nasaspaceflight.com/index.php?topic=32006.msg2391098#msg2391098|access-date=31 July 2022|website=forum.nasaspaceflight.com|archive-date=31 July 2022|archive-url=https://web.archive.org/web/20220731072946/https://forum.nasaspaceflight.com/index.php?topic=32006.msg2391098#msg2391098|url-status=live}}{{cite web|title=The Russian Nauka/Multipurpose Laboratory Module (MLM) General Thread|url=https://forum.nasaspaceflight.com/index.php?topic=23444.msg2334840#msg2334840|access-date=25 March 2022|website=forum.nasaspaceflight.com|archive-date=4 April 2022|archive-url=https://web.archive.org/web/20220404014507/https://forum.nasaspaceflight.com/index.php?topic=23444.msg2334840#msg2334840|url-status=live}}{{Cite web|url=https://www.russianspaceweb.com/iss-fgb2-mlm-integration.html|title=Russia to bump its ISS crew back to three|last=Zak|first=Anatoly|access-date=25 March 2022|url-status=live|archive-url=https://web.archive.org/web/20230811164158/https://www.russianspaceweb.com/iss-fgb2-mlm-integration.html|archive-date=11 August 2023|website=RussianSpaceWeb}} It was taken outside and installed on the ERA aft facing base point on Nauka during the VKD-55 spacewalk.{{Cite web|url=https://blogs.nasa.gov/spacestation/2022/11/16/cosmonauts-prep-for-thursday-spacewalk-dragon-targets-monday-launch/|title=Cosmonauts Prep for Thursday Spacewalk, Dragon Targets Monday Launch|last=Garcia|first=Mark|date=16 November 2022|publisher=NASA|access-date=16 November 2022|url-status=live|archive-url=https://web.archive.org/web/20230810132145/https://blogs.nasa.gov/spacestation/2022/11/16/cosmonauts-prep-for-thursday-spacewalk-dragon-targets-monday-launch/|archive-date=10 August 2023|website=NASA Blogs}}{{Cite web|url=https://blogs.nasa.gov/spacestation/2022/11/17/cosmonauts-begin-first-in-a-series-of-spacewalks-for-station-maintenance/|title=Cosmonauts Begin First in a Series of Spacewalks for Station Maintenance|last=Lavelle|first=Heidi|date=17 November 2022|publisher=NASA|access-date=17 November 2022|url-status=live|archive-url=https://web.archive.org/web/20230810130808/https://blogs.nasa.gov/spacestation/2022/11/17/cosmonauts-begin-first-in-a-series-of-spacewalks-for-station-maintenance/|archive-date=10 August 2023|website=NASA Blogs}}{{Cite web|url=https://blogs.nasa.gov/spacestation/2022/11/17/cosmonauts-finish-spacewalk-for-work-on-science-module/|title=Cosmonauts Finish Spacewalk for Work on Science Module|last=Garcia|first=Mark|date=17 November 2022|publisher=NASA|access-date=17 November 2022|url-status=live|archive-url=https://web.archive.org/web/20230329110535/https://blogs.nasa.gov/spacestation/2022/11/17/cosmonauts-finish-spacewalk-for-work-on-science-module/|archive-date=29 March 2023|website=NASA Blogs}}{{Cite news|url=https://www.space.com/iss-spacewalk-russian-radiator-move-prep|title=Russian cosmonauts complete station spacewalk to ready radiator for move|last=Pearlman|first=Robert Z.|date=17 November 2022|access-date=23 November 2022|url-status=live|archive-url=https://web.archive.org/web/20231124215252/https://www.space.com/iss-spacewalk-russian-radiator-move-prep|archive-date=24 November 2023|work=Space.com}}

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| image1 = Iss017e011097.jpg

| caption1 = Commander Volkov stands on Pirs with his back to the Soyuz whilst operating the manual
Strela crane (which is holding photographer Oleg Kononenko).

| image2 = Dextrereallyhasnohead.jpg

| caption2 = Dextre, like many of the station's experiments and robotic arms, can be operated from Earth, allowing tasks to be performed while the crew sleeps.

}}

The Integrated Truss Structure (ITS) serves as a base for the station's primary remote manipulator system, the Mobile Servicing System (MSS), which is composed of three main components:

• Canadarm2, the largest robotic arm on the ISS, has a mass of {{convert|1800|kg|lb}} and is used to: dock and manipulate spacecraft and modules on the USOS; hold crew members and equipment in place during EVAs; and move Dextre to perform tasks.{{cite web|date=8 January 2013|title=Canadarm2 and the Mobile Servicing System|url=http://www.nasa.gov/mission_pages/station/structure/elements/mss.html|access-date=22 June 2015|publisher=NASA|archive-date=23 March 2009|archive-url=https://web.archive.org/web/20090323030711/http://www.nasa.gov/mission_pages/station/structure/elements/mss.html|url-status=dead}}
• Dextre is a {{convert|1560|kg|lb|abbr=on}} robotic manipulator that has two arms and a rotating torso, with power tools, lights, and video for replacing orbital replacement units (ORUs) and performing other tasks requiring fine control.{{Cite web|url=https://www.asc-csa.gc.ca/eng/iss/dextre/|title=Dextre, the International Space Station's Robotic Handyman|date=18 April 2011|publisher=Canadian Space Agency|access-date=22 June 2015|url-status=live|archive-url=https://web.archive.org/web/20230405001741/https://www.asc-csa.gc.ca/eng/iss/dextre/|archive-date=5 April 2023}}
• The Mobile Base System (MBS) is a platform that rides on rails along the length of the station's main truss, which serves as a mobile base for Canadarm2 and Dextre, allowing the robotic arms to reach all parts of the USOS.{{Cite web|url=https://www.asc-csa.gc.ca/eng/iss/mobile-base/|title=Mobile Base System|publisher=Canadian Space Agency|access-date=22 June 2015|url-status=live|archive-url=https://web.archive.org/web/20230327123655/http://www.asc-csa.gc.ca/eng/iss/mobile-base/|archive-date=27 March 2023}}

A grapple fixture was added to Zarya on STS-134 to enable Canadarm2 to inchworm itself onto the ROS. Also installed during STS-134 was the {{convert|50|ft|m|abbr=on|order=flip}} Orbiter Boom Sensor System (OBSS), which had been used to inspect heat shield tiles on Space Shuttle missions and which can be used on the station to increase the reach of the MSS. Staff on Earth or the ISS can operate the MSS components using remote control, performing work outside the station without the need for space walks.

Japan's Remote Manipulator System, which services the Kibō Exposed Facility,{{cite web|date=29 August 2008|title=Remote Manipulator System: About Kibo|url=http://kibo.jaxa.jp/en/about/kibo/rms/|url-status=dead|archive-url=https://web.archive.org/web/20080320035809/http://kibo.jaxa.jp/en/about/kibo/rms/|archive-date=20 March 2008|access-date=4 October 2009|publisher=JAXA}} was launched on STS-124 and is attached to the Kibō Pressurised Module.{{cite web|date=14 January 2002|title=International Space Station Status Report #02-03|url=http://www.nasa.gov/centers/johnson/news/station/2002/iss02-03.txt|access-date=4 October 2009|publisher=NASA|archive-date=11 March 2010|archive-url=https://web.archive.org/web/20100311105930/http://www.nasa.gov/centers/johnson/news/station/2002/iss02-03.txt|url-status=dead}} The arm is similar to the Space Shuttle arm as it is permanently attached at one end and has a latching end effector for standard grapple fixtures at the other.

The European Robotic Arm, which will service the ROS, was launched alongside the Nauka module.{{Cite news|url=https://tass.com/science/1139385|title=Russia postpones launch of Nauka research module to orbital outpost to 2021|date=2 April 2020|agency=TASS|access-date=1 March 2021|url-status=live|archive-url=https://web.archive.org/web/20230810143935/https://tass.com/science/1139385|archive-date=10 August 2023}} The ROS does not require spacecraft or modules to be manipulated, as all spacecraft and modules dock automatically and may be discarded the same way. Crew use the two Strela ({{langx|ru|Стрела́||Arrow}}) cargo cranes during EVAs for moving crew and equipment around the ROS. Each Strela crane has a mass of {{cvt|45|kg}}.

{{Multiple image

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| direction = horizontal

| image1 = Sts110-363-001.jpg

| caption1 = The Pirs module attached to the ISS

| image2 = ISS-65 Pirs docking compartment separates from the Space Station.jpg

| caption2 = ISS-65 Pirs docking compartment separates from the International Space Station.

}}

{{main|2 = Pirs (ISS module)}}

Pirs (Russian: Пирс, lit. 'Pier') was launched on 14 September 2001, as ISS Assembly Mission 4R, on a Russian Soyuz-U rocket, using a modified Progress spacecraft, Progress M-SO1, as an upper stage. Pirs was undocked by Progress MS-16 on 26 July 2021, 10:56 UTC, and deorbited on the same day at 14:51 UTC to make room for the Nauka module to be attached to the space station. Prior to its departure, Pirs served as the primary Russian airlock on the station, being used to store and refurbish the Russian Orlan spacesuits.

{{main|Axiom Station}}

File:Axiom modules connected to ISS.jpg, made prior to assembly plan changes]]

In January 2020, NASA awarded Axiom Space a contract to build a commercial module for the ISS. The contract is under the NextSTEP2 program. NASA negotiated with Axiom on a firm fixed-price contract basis to build and deliver the module, which will attach to the forward port of the space station's Harmony (Node 2) module. Although NASA only commissioned one module, Axiom planned to build an entire segment consisting of five modules, including a node module, an orbital research and manufacturing facility, a crew habitat, and a "large-windowed Earth observatory". The Axiom segment was expected to greatly increase the capabilities and value of the space station, allowing for larger crews and private spaceflight by other organisations. Axiom planned to convert the segment into a stand-alone space station once the ISS is decommissioned, with the intention that this would act as a successor to the ISS.{{Cite news|url=https://spaceflightnow.com/2020/01/28/axiom-wins-nasa-approval-to-attach-commercial-habitat-to-space-station/|title=Axiom wins NASA approval to attach commercial habitat to space station|last=Clark|first=Stephen|date=28 January 2020|access-date=29 January 2020|url-status=live|archive-url=https://web.archive.org/web/20231121185755/https://spaceflightnow.com/2020/01/28/axiom-wins-nasa-approval-to-attach-commercial-habitat-to-space-station/|archive-date=21 November 2023|work=Spaceflight Now}}{{Cite news|url=https://techcrunch.com/2020/01/27/nasa-taps-startup-axiom-space-for-the-first-habitable-commercial-module-for-the-space-station/|title=NASA taps startup Axiom Space for the first habitable commercial module for the Space Station|last=Etherington|first=Darrell|date=27 January 2020|access-date=29 January 2020|url-status=live|archive-url=https://web.archive.org/web/20200128010232/https://techcrunch.com/2020/01/27/nasa-taps-startup-axiom-space-for-the-first-habitable-commercial-module-for-the-space-station/|archive-date=28 January 2020|work=TechCrunch}}{{Cite news|url=https://www.geekwire.com/2020/nasa-clears-axiom-space-put-commercial-habitat-space-station-boeings-help/|title=NASA clears Axiom Space to put commercial habitat on space station, with Boeing on the team|last=Boyle|first=Alan|date=27 January 2020|access-date=29 January 2020|url-status=live|archive-url=https://web.archive.org/web/20230406054511/https://www.geekwire.com/2020/nasa-clears-axiom-space-put-commercial-habitat-space-station-boeings-help/|archive-date=6 April 2023|work=GeekWire}} Canadarm2 is planned to continue its operations on Axiom Station after the retirement of ISS in 2030.{{Cite web|url=https://www.axiomspace.com/axiom-station/assembly-sequence|title=Axiom Station Assembly Sequence – Axiom Space Axiom Space|publisher=Axiom Space|access-date=9 August 2021|url-status=live|archive-url=https://web.archive.org/web/20230810145840/https://www.axiomspace.com/axiom-station/assembly-sequence|archive-date=10 August 2023}} In December 2024, Axiom Space revised their station assembly plans to require only one module to dock with the ISS before assembling Axiom Station in an independent orbit.

{{As of|December 2024}}, Axiom Space expects to launch one module, the Payload Power Thermal Module (PPTM), to the ISS no earlier than 2027.{{cite web |last=Foust |first=Jeff |url=https://spacenews.com/axiom-space-revises-space-station-assembly-plans/ |title=Axiom Space revises space station assembly plans |work=SpaceNews |date=18 December 2024 |access-date=18 December 2024}} PPTM is expected to remain at the ISS until the launch of Axiom's Habitat One (Hab-1) module about one year later, after which it will detach from the ISS to join with Hab-1.

The US Deorbit Vehicle (USDV) is a NASA-provided spacecraft intended to perform a controlled de-orbit and demise of the station after the end of its operational life in 2030. In June 2024, NASA awarded SpaceX a contract to build the Deorbit Vehicle.{{Cite web|url=http://www.collectspace.com/news/news-091523a-soyuz-ms-24-launch-space-station.html|title=Russia's Soyuz MS-24 launches crew for up to yearlong stay on space station|access-date=15 September 2023|url-status=live|archive-url=https://web.archive.org/web/20231006173029/http://www.collectspace.com/news/news-091523a-soyuz-ms-24-launch-space-station.html|archive-date=6 October 2023|website=collectSPACE.com}} NASA plans to de-orbit ISS as soon as they have the "minimum capability" in orbit: "the USDV and at least one commercial station."{{cite news|title=NASA weighing options for continuous human presence in LEO after ISS|url=https://spacenews.com/nasa-weighing-options-for-continuous-human-presence-in-leo-after-iss/|work=SpaceNews|last=Foust|first=Jeff|date=16 October 2024|access-date=17 October 2024}}

{{multiple image

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| image1 = ISS Habitation module.jpg

| caption1 = The cancelled Habitation module under construction at Michoud in 1997

| image2 = Nautilus-X demonstrator docked to the ISS (side).webp

| caption2 = Rendering of the Nautilus-X Centrifuge Demonstrator docked to the ISS (side)

}}

Several modules developed or planned for the station were cancelled over the course of the ISS programme. Reasons include budgetary constraints, the modules becoming unnecessary, and station redesigns after the 2003 Columbia disaster. The US Centrifuge Accommodations Module would have hosted science experiments in varying levels of artificial gravity.{{cite web|title=CAM – location?|url=http://forum.nasaspaceflight.com/index.php?topic=12560.msg265342|access-date=12 October 2009|website=NASA Spaceflight Forums|archive-date=11 October 2012|archive-url=https://web.archive.org/web/20121011031151/http://forum.nasaspaceflight.com/index.php?PHPSESSID=67c39f0a2f4c8510242de183bae73e6f&topic=12560.msg265342|url-status=live}} The US Habitation Module would have served as the station's living quarters. Instead, the living quarters are now spread throughout the station.{{Cite news|url=https://www.space.com/2050-nasa-recycles-iss-module-life-support-research.html|title=NASA Recycles Former ISS Module for Life Support Research|last=Malik|first=Tariq|date=14 February 2006|access-date=11 March 2009|url-status=live|archive-url=https://web.archive.org/web/20230812225629/https://www.space.com/2050-nasa-recycles-iss-module-life-support-research.html|archive-date=12 August 2023|work=Space.com}} The US Interim Control Module and ISS Propulsion Module would have replaced the functions of Zvezda in case of a launch failure.{{Cite web|url=http://code8200.nrl.navy.mil/icm.html|title=ICM Interim Control Module|publisher=U.S. Naval Center for Space Technology|url-status=dead|archive-url=https://web.archive.org/web/20070208164211/http://code8200.nrl.navy.mil/icm.html|archive-date=8 February 2007}} Two Russian Research Modules were planned for scientific research.{{Cite web|url=http://www.boeing.com/defense-space/space/spacestation/components/russian_laboratory.html|title=Russian Research Modules|publisher=Boeing|access-date=21 June 2009|url-status=dead|archive-url=https://web.archive.org/web/20100208034625/http://www.boeing.com/defense-space/space/spacestation/components/russian_laboratory.html|archive-date=8 February 2010}} They would have docked to a Russian Universal Docking Module.{{Cite web|url=https://www.russianspaceweb.com/iss_russia.html|title=Russian segment of the ISS|last=Zak|first=Anatoly|access-date=3 October 2009|url-status=live|archive-url=https://web.archive.org/web/20230406134221/https://russianspaceweb.com/iss_russia.html|archive-date=6 April 2023|website=RussianSpaceWeb}} The Russian Science Power Platform would have supplied power to the Russian Orbital Segment independent of the ITS solar arrays.

Science Power Module 1 (SPM-1, also known as NEM-1) and Science Power Module 2 (SPM-2, also known as NEM-2) are modules that were originally planned to arrive at the ISS no earlier than 2024, and dock to the Prichal module, which is docked to the Nauka module.{{Cite web|url=http://www.russianspaceweb.com/2024.html#nem|title=Russian space program in 2024|last=Zak|first=Anatoly|date=22 June 2020|access-date=23 June 2020|url-status=live|archive-url=https://web.archive.org/web/20231102064550/https://russianspaceweb.com/2024.html#nem|archive-date=2 November 2023|website=RussianSpaceWeb}} In April 2021, Roscosmos announced that NEM-1 would be repurposed to function as the core module of the proposed Russian Orbital Service Station (ROSS), launching no earlier than 2027{{Cite news|date=24 January 2023|title=Russia to set up national orbital outpost in 2027 – Roscosmos|url=https://tass.com/science/1566383|url-status=live|archive-url=https://web.archive.org/web/20230609221841/https://tass.com/science/1566383|archive-date=9 June 2023|access-date=31 January 2023|agency=TASS}} and docking to the free-flying Nauka module.{{Cite web|url=https://tass.ru/kosmos/11934057|title=Роскосмос примет решение о пути развития российской орбитальной станции до конца июля|trans-title=Roscosmos to decide development path of Russian orbital station by end of July|date=19 July 2021|agency=TASS|language=ru|access-date=20 July 2021|url-status=live|archive-url=https://web.archive.org/web/20230810131618/https://tass.ru/kosmos/11934057|archive-date=10 August 2023}}{{Cite web|url=https://www.russianspaceweb.com/ros.html|title=Russian Orbital Service Station, ROSS|last=Zak|first=Anatoly|date=16 April 2021|access-date=26 April 2021|url-status=live|archive-url=https://web.archive.org/web/20230814171139/https://www.russianspaceweb.com/ros.html|archive-date=14 August 2023|website=RussianSpaceWeb}} NEM-2 may be converted into another core "base" module, which would be launched in 2028.{{Cite web|url=https://www.roscosmos.ru/30863/|title=Научно-энергетический модуль запустят на "Ангаре" с Восточного|trans-title=The Science Power Module will be launched on an Angara from Vostochny|date=24 April 2021|publisher=Roscosmos|language=ru|access-date=26 April 2021|url-status=live|archive-url=https://web.archive.org/web/20220822035249/https://www.roscosmos.ru/30863/|archive-date=22 August 2022}}

{{main|B330}}

Designed by Bigelow Aerospace. In August 2016, Bigelow negotiated an agreement with NASA to develop a full-size ground prototype Deep Space Habitation based on the B330 under the second phase of Next Space Technologies for Exploration Partnerships. The module was called the Expandable Bigelow Advanced Station Enhancement (XBASE), as Bigelow hoped to test the module by attaching it to the International Space Station. However, in March 2020, Bigelow laid off all 88 of its employees, and {{As of|2024|02|lc=y}} the company remains dormant and is considered defunct,{{cite news|url=https://spacenews.com/bigelow-aerospace-lays-off-entire-workforce/|title=Bigelow Aerospace lays off entire workforce|publisher=SpaceNews|first=Jeff|last=Foust|date=23 March 2020|access-date=2 December 2023|archive-date=24 March 2020|archive-url=https://archive.today/20200324011153/https://spacenews.com/bigelow-aerospace-lays-off-entire-workforce/|url-status=live}}{{Cite web|last=Clark|first=Stephen|date=4 August 2023|title=Trans-Atlantic joint venture aims to build new "international" space station|url=https://arstechnica.com/space/2023/08/trans-atlantic-joint-venture-aims-to-build-new-international-space-station/|access-date=15 February 2024|website=Ars Technica|archive-date=27 February 2024|archive-url=https://web.archive.org/web/20240227023202/https://arstechnica.com/space/2023/08/trans-atlantic-joint-venture-aims-to-build-new-international-space-station/|url-status=live}} making it appear unlikely that the XBASE module will ever be launched.

{{main|Nautilus-X}}

A proposal was put forward in 2011 for a first in-space demonstration of a sufficiently scaled centrifuge for artificial partial-g gravity effects. It was designed to become a sleep module for the ISS crew. The project was cancelled in favour of other projects due to budget constraints.{{cite web|last=Hollingham|first=Richard|title=The rise and fall of artificial gravity|publisher=BBC Home|date=18 November 2014|url=https://www.bbc.com/future/article/20130121-worth-the-weight|access-date=22 July 2024}}

{{Main|ISS ECLSS|Chemical oxygen generator}}

The critical systems are the atmosphere control system, the water supply system, the food supply facilities, the sanitation and hygiene equipment, and fire detection and suppression equipment. The Russian Orbital Segment's life support systems are contained in the Zvezda service module. Some of these systems are supplemented by equipment in the USOS. The Nauka laboratory has a complete set of life support systems.

File:SpaceStationCycle.svg

The atmosphere on board the ISS is similar to that of Earth.{{cite web|last=Freudenrich|first=Craig|date=20 November 2000|title=How Space Stations Work|url=http://science.howstuffworks.com/space-station2.htm|url-status=dead|archive-url=https://web.archive.org/web/20081212014934/http://science.howstuffworks.com/space-station2.htm|archive-date=12 December 2008|access-date=23 November 2008|publisher=Howstuffworks}} Normal air pressure on the ISS is {{cvt|101.3|kPa}};{{cite web|title=5–8: The Air Up There|url=http://nasaexplores.com/show2_5_8a.php?id=04-032&gl=58|url-status=dead|archive-url=https://archive.today/20041218024247/http://nasaexplores.com/show2_5_8a.php?id=04-032&gl=58|archive-date=18 December 2004|access-date=31 October 2008|website=NASAexplores|publisher=NASA}} the same as at sea level on Earth. An Earth-like atmosphere offers benefits for crew comfort, and is much safer than a pure oxygen atmosphere, because of the increased risk of a fire such as that responsible for the deaths of the Apollo 1 crew.{{Cite report|url=https://history.nasa.gov/as204_senate_956.pdf|title=Apollo 204 Accident: Report of the Committee on Aeronautical and Space Sciences, United States Senate|last1=Anderson|first1=Clinton P.|date=30 January 1968|publisher=US Government Printing Office|location=Washington, D.C.|page=8|id=Report No. 956|url-status=live|archive-url=https://web.archive.org/web/20230810130754/https://history.nasa.gov/as204_senate_956.pdf|archive-date=10 August 2023|display-authors=etal}}{{better source needed|Source is 54 years old and does NOT conclude that 100% oxygen atmospheres should be completely avoided – the problem of Apollo 1 was the testing with pure oxygen at 16.7 psi (1.2 atm) overpressure, i.e. six times the natural partial pressure of oxygen. It explicitly states on p. 11 that "NASA has recommended by detailed review that the inflight cabin atmosphere, outside the Earth's atmosphere, should continue to be 100 percent oxygen at 5 p.s.i.A." (c. 0.3 atm). FWIW, Andy Weir's 2021 SF novel Project Hail Mary claims that an Earth-like atmosphere is maintained in near-Earth space stations to simplify evacuation in case of emergency.|date=January 2022}} Earth-like atmospheric conditions have been maintained on all Russian and Soviet spacecraft.{{Cite book|last1=Davis|first1=Jeffrey R.|title=Fundamentals of Aerospace Medicine|last2=Johnson|first2=Robert|last3=Stepanek|first3=Jan|publisher=Lippincott Williams & Wilkins|year=2008|volume=XII|place=Philadelphia, Pennsylvania, USA|pages=261–264|name-list-style=amp}}

The Elektron system aboard Zvezda and a similar system in Destiny generate oxygen aboard the station.{{Cite news|url=https://www.space.com/2052-air-apparent-oxygen-systems-iss.html|title=Air Apparent: New Oxygen Systems for the ISS|last=Malik|first=Tariq|date=15 February 2006|access-date=21 November 2008|url-status=live|archive-url=https://web.archive.org/web/20230814171139/https://www.russianspaceweb.com/ros.html|archive-date=14 August 2023|work=Space.com}} The crew has a backup option in the form of bottled oxygen and Solid Fuel Oxygen Generation (SFOG) canisters, a chemical oxygen generator system.{{cite web|first=Patrick L.|last=Barry|date=13 November 2000|title=Breathing Easy on the Space Station|url=https://science.nasa.gov/headlines/y2000/ast13nov_1.htm|url-status=dead|archive-url=https://web.archive.org/web/20080921141609/https://science.nasa.gov/headlines/y2000/ast13nov_1.htm|archive-date=21 September 2008|access-date=21 November 2008|publisher=NASA}} Carbon dioxide is removed from the air by the Vozdukh system in Zvezda. Other by-products of human metabolism, such as methane from the intestines and ammonia from sweat, are removed by activated charcoal filters.

Part of the ROS atmosphere control system is the oxygen supply. Triple-redundancy is provided by the Elektron unit, solid fuel generators, and stored oxygen. The primary supply of oxygen is the Elektron unit which produces {{chem2|O2}} and {{chem2|H2}} by electrolysis of water and vents {{chem2|H2}} overboard. The {{cvt|1|kW}} system uses approximately one litre of water per crew member per day. This water is either brought from Earth or recycled from other systems. Mir was the first spacecraft to use recycled water for oxygen production. The secondary oxygen supply is provided by burning oxygen-producing Vika cartridges (see also ISS ECLSS). Each 'candle' takes 5–20 minutes to decompose at {{convert|450|-|500|C}}, producing {{convert|600|L}} of {{chem2|O2}}. This unit is manually operated.{{cite web|url=http://suzymchale.com/ruspace/issrslss.html|title=RuSpace {{!}} ISS Russian Segment Life Support System|archive-url=https://web.archive.org/web/20110809155257/http://suzymchale.com/ruspace/issrslss.html|archive-date=9 August 2011|url-status=dead|website=Suzymchale.com|access-date=8 October 2011}}

The US Orbital Segment (USOS) has redundant supplies of oxygen, from a pressurised storage tank on the Quest airlock module delivered in 2001, supplemented ten years later by ESA-built Advanced Closed-Loop System (ACLS) in the Tranquility module (Node 3), which produces {{chem2|O2}} by electrolysis.{{Cite web|url=https://science.nasa.gov/science-news/science-at-nasa/2000/ast13nov_1|title=Breathing Easy on the Space Station|date=13 November 2000|publisher=NASA|access-date=8 October 2011|url-status=dead|archive-url=https://web.archive.org/web/20190311204439/https://science.nasa.gov/science-news/science-at-nasa/2000/ast13nov_1|archive-date=11 March 2019}} Hydrogen produced is combined with carbon dioxide from the cabin atmosphere and converted to water and methane.

{{Main|Electrical system of the International Space Station|External Active Thermal Control System}}

{{multiple image

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| total_width = 400

| image1 = ROSSA.jpg

| caption1 = Russian solar arrays, backlit by sunset

| image2 = P4 deployed.jpg

| caption2 = One of the eight truss mounted pairs of USOS solar arrays

| image3 = ISS new iROSA deployed.jpg

| caption3 = ISS new roll out solar array as seen from a zoom camera on the P6 Truss

}}

Double-sided solar arrays provide electrical power to the ISS. These bifacial cells collect direct sunlight on one side and light reflected off from the Earth on the other, and are more efficient and operate at a lower temperature than single-sided cells commonly used on Earth.{{Cite conference|url=http://wenku.baidu.com/view/a815121ffc4ffe473368ab7a.html|title=The early history of bifacial solar cell|last=Cuevas|first=Andrés|date=January 2005|publisher=WIP Renewable Energies|access-date=14 August 2012|url-status=live|archive-url=https://web.archive.org/web/20230405131511/https://wenku.baidu.com/view/a815121ffc4ffe473368ab7a.html|archive-date=5 April 2023|conference=European Photovoltaic Solar Energy Conference|hdl=1885/84487|volume=20}}

The Russian segment of the station, like most spacecraft, uses 28 V low voltage DC from two rotating solar arrays mounted on Zvezda. The USOS uses 130–180 V DC from the USOS PV array. Power is stabilised and distributed at 160 V DC and converted to the user-required 124 V DC. The higher distribution voltage allows smaller, lighter conductors, at the expense of crew safety. The two station segments share power with converters.

The USOS solar arrays are arranged as four wing pairs, for a total production of 75 to 90 kilowatts. These arrays normally track the Sun to maximise power generation. Each array is about {{convert|375|m2|sqft|0|abbr=on}} in area and {{convert|58|m|ft|0|abbr=on}} long. In the complete configuration, the solar arrays track the Sun by rotating the alpha gimbal once per orbit; the beta gimbal follows slower changes in the angle of the Sun to the orbital plane. The Night Glider mode aligns the solar arrays parallel to the ground at night to reduce the significant aerodynamic drag at the station's relatively low orbital altitude.{{Cite journal|author1=G. Landis|author2=C-Y. Lu|year=1991|title=Solar Array Orientation Options for a Space Station in Low Earth Orbit|journal=Journal of Propulsion and Power|volume=7|issue=1|pages=123–125|doi=10.2514/3.23302}}

The station originally used rechargeable nickel–hydrogen batteries ({{chem2|NiH2}}) for continuous power during the 45 minutes of every 90-minute orbit that it is eclipsed by the Earth. The batteries are recharged on the day side of the orbit. They had a 6.5-year lifetime (over 37,000 charge/discharge cycles) and were regularly replaced over the anticipated 20-year life of the station.{{cite web|first=Thomas B.|last=Miller|date=24 April 2000|title=Nickel-Hydrogen Battery Cell Life Test Program Update for the International Space Station|url=https://www.grc.nasa.gov/WWW/RT/RT1999/5000/5420miller.html|url-status=dead|archive-url=https://web.archive.org/web/20090825125740/https://www.grc.nasa.gov/WWW/RT/RT1999/5000/5420miller.html|archive-date=25 August 2009|access-date=27 November 2009|series=Research & Technology|publisher=NASA{{\}}Glenn Research Center|website=grc.nasa.gov}} Starting in 2016, the nickel–hydrogen batteries were replaced by lithium-ion batteries, which are expected to last until the end of the ISS program.{{Cite news|url=https://spaceflightnow.com/2016/12/13/japanese-htv-makes-battery-delivery-to-international-space-station/|title=Japanese HTV makes battery delivery to International Space Station|last=Clark|first=Stephen|date=13 December 2016|access-date=29 January 2017|url-status=live|archive-url=https://web.archive.org/web/20230810132031/https://spaceflightnow.com/2016/12/13/japanese-htv-makes-battery-delivery-to-international-space-station/|archive-date=10 August 2023|work=Spaceflight Now}}

The station's large solar panels generate a high potential voltage difference between the station and the ionosphere. This could cause arcing through insulating surfaces and sputtering of conductive surfaces as ions are accelerated by the spacecraft plasma sheath. To mitigate this, plasma contactor units create current paths between the station and the ambient space plasma.{{cite web|last=Patterson|first=Michael J.|date=18 June 1999|title=Cathodes Delivered for Space Station Plasma Contactor System|url=https://www.grc.nasa.gov/WWW/RT/RT1998/5000/5430patterson.html|url-status=dead|archive-url=https://web.archive.org/web/20110705135954/https://www.grc.nasa.gov/WWW/RT/RT1998/5000/5430patterson.html|archive-date=5 July 2011|series=Research & Technology|publisher=NASA{{\}}Lewis Research Center|website=grc.nasa.gov}}

File:EATCS.png

The station's systems and experiments consume a large amount of electrical power, almost all of which is converted to heat. To keep the internal temperature within workable limits, a passive thermal control system (PTCS) is made of external surface materials, insulation such as MLI, and heat pipes. If the PTCS cannot keep up with the heat load, an External Active Thermal Control System (EATCS) maintains the temperature. The EATCS consists of an internal, non-toxic, water coolant loop used to cool and dehumidify the atmosphere, which transfers collected heat into an external liquid ammonia loop. From the heat exchangers, ammonia is pumped into external radiators that emit heat as infrared radiation, then the ammonia is cycled back to the station.{{Cite web|url=https://science.nasa.gov/science-news/science-at-nasa/2001/ast21mar_1/|title=Staying Cool on the ISS|last1=Price|first1=Steve|last2=Phillips|first2=Tony|last3=Knier|first3=Gil|date=21 March 2001|publisher=NASA|access-date=22 July 2016|url-status=dead|archive-url=https://web.archive.org/web/20230203012526/https://science.nasa.gov/science-news/science-at-nasa/2001/ast21mar_1/|archive-date=3 February 2023}} The EATCS provides cooling for all the US pressurised modules, including Kibō and Columbus, as well as the main power distribution electronics of the S0, S1 and P1 trusses. It can reject up to 70 kW. This is much more than the 14 kW of the Early External Active Thermal Control System (EEATCS) via the Early Ammonia Servicer (EAS), which was launched on STS-105 and installed onto the P6 Truss.{{Cite tech report|url=https://www.nasa.gov/wp-content/uploads/2021/02/473486main_iss_atcs_overview.pdf|title=Active Thermal Control System (ATCS) Overview|publisher=Boeing|access-date=8 October 2011|url-status=live|archive-url=https://web.archive.org/web/20231016111319/https://www.nasa.gov/wp-content/uploads/2021/02/473486main_iss_atcs_overview.pdf|archive-date=16 October 2023}}

{{Main|Tracking and Data Relay Satellite|Luch (satellite)}}

{{See also|ThinkPad#Use in space}}The ISS relies on various radio communication systems to provide telemetry and scientific data links between the station and mission control centres. Radio links are also used during rendezvous and docking procedures and for audio and video communication between crew members, flight controllers and family members. As a result, the ISS is equipped with internal and external communication systems used for different purposes.

The Russian Orbital Segment primarily uses the Lira antenna mounted on Zvezda for direct ground communication.{{cite web|last1=Mathews|first1=Melissa|last2=Hartsfield|first2=James|date=25 March 2005|title=International Space Station Status Report: SS05-015|url=http://www.nasa.gov/home/hqnews/2005/mar/HQ_ss05015_ISS_status_report.html|url-status=dead|archive-url=https://web.archive.org/web/20120111144205/http://www.nasa.gov/home/hqnews/2005/mar/HQ_ss05015_ISS_status_report.html|archive-date=11 January 2012|access-date=11 January 2010|website=NASA News|publisher=NASA}} It also had the capability to utilize the Luch data relay satellite system, which was in a state of disrepair when the station was built,{{Cite book|last=Harland|first=David|url=https://archive.org/details/storyofspacestat0000harl|title=The Story of Space Station Mir|publisher=Springer-Verlag New York Incorporated|year=2004|isbn=978-0-387-23011-5|location=New York|url-access=registration}}{{Cite book|last=Harvey|first=Brian|title=The rebirth of the Russian space program: 50 years after Sputnik, new frontiers|publisher=Springer Praxis Books|year=2007|isbn=978-0-387-71354-0|page=263}} but was restored to operational status in 2011 and 2012 with the launch of Luch-5A and Luch-5B.{{cite web|last=Zak|first=Anatoly|date=4 January 2010|title=Space exploration in 2011|url=http://www.russianspaceweb.com/2011.html|url-status=dead|archive-url=https://web.archive.org/web/20100626095747/http://www.russianspaceweb.com/2011.html|archive-date=26 June 2010|access-date=12 January 2010|website=RussianSpaceWeb}} Additionally, the Voskhod-M system provides internal telephone communications and VHF radio links to ground control.{{cite web|date=2 May 2010|title=ISS On-Orbit Status 05/02/10|url=http://www.nasa.gov/directorates/somd/reports/iss_reports/2010/05022010.html|access-date=7 July 2010|publisher=NASA|archive-date=19 January 2012|archive-url=https://web.archive.org/web/20120119101404/http://www.nasa.gov/directorates/heo/reports/iss_reports/2010/05022010.html|url-status=dead}}

The US Orbital Segment (USOS) makes use of two separate radio links: S band (audio, telemetry, commanding – located on the P1/S1 truss) and K_u band (audio, video and data – located on the Z1 truss) systems. These transmissions are routed via the United States Tracking and Data Relay Satellite System (TDRSS) in geostationary orbit, allowing for almost continuous real-time communications with Christopher C. Kraft Jr. Mission Control Center (MCC-H) in Houston, Texas.{{Cite book|last=Catchpole|first=John E.|url={{Google books|VsTdriusftgC|keywords=|text=|plainurl=yes}}|title=The International Space Station: Building for the Future|publisher=Springer-Praxis|year=2008|isbn=978-0-387-78144-0}}{{Cite web|url=http://www.boeing.com/defense-space/space/spacestation/systems/communications_tracking.html|title=Communications and Tracking|publisher=Boeing|access-date=30 November 2009|url-status=dead|archive-url=https://web.archive.org/web/20080611115319/http://www.boeing.com/defense-space/space/spacestation/systems/communications_tracking.html|archive-date=11 June 2008|website=Integrated Defense Systems}} Data channels for the Canadarm2, European Columbus laboratory and Japanese Kibō modules were originally also routed via the S band and K_u band systems, with the European Data Relay System and a similar Japanese system intended to eventually complement the TDRSS in this role.{{cite web|date=24 February 1998|title=Memorandum of Understanding Between the National Aeronautics and Space Administration of the United States of America and the Government of Japan Concerning Cooperation on the Civil International Space Station|url=http://www.nasa.gov/mission_pages/station/structure/elements/nasa_japan.html|access-date=19 April 2009|publisher=NASA|archive-date=11 January 2012|archive-url=https://web.archive.org/web/20120111144216/http://www.nasa.gov/mission_pages/station/structure/elements/nasa_japan.html|url-status=dead}}

UHF radio is used by astronauts and cosmonauts conducting EVAs and other spacecraft that dock to or undock from the station. Automated spacecraft are fitted with their own communications equipment; the ATV used a laser attached to the spacecraft and the Proximity Communications Equipment attached to Zvezda to accurately dock with the station.{{Cite web|url=https://spaceref.com/press-release/issatv-communication-system-flight-on-soyuz/|title=ISS/ATV communication system flight on Soyuz|date=28 February 2005|publisher=EADS Astrium|access-date=30 November 2009}}{{Cite news|url=https://www.nasaspaceflight.com/2009/11/sts-129-support-dragon-communication-demo-iss/|title=STS-129 ready to support Dragon communication demo with ISS|last=Bergin|first=Chris|date=10 November 2009|access-date=30 November 2009|url-status=live|archive-url=https://web.archive.org/web/20230811174816/https://www.nasaspaceflight.com/2009/11/sts-129-support-dragon-communication-demo-iss/|archive-date=11 August 2023|work=NASASpaceFlight.com}}

{{multiple image

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| image1 = ISS-38 EVA-1 Laptops.jpg

| caption1 = An array of laptops in the US lab

| image2 = STS-128 ISS-20 Destiny Canadarm2.jpg

| caption2 = Laptop computers surround the Canadarm2 console.

| image3 = ISS laptop hard drive failure error message.jpg

| caption3 = An error message displays a problem with a hard drive on a laptop aboard the ISS.

}}

The US Orbital Segment of the ISS is equipped with approximately 100 commercial off-the-shelf laptops running Windows or Linux.{{Cite news|last=Heath|first=Nick|date=23 May 2016|title=From Windows 10, Linux, iPads, iPhones to HoloLens: The tech astronauts use on the ISS|url=https://www.techrepublic.com/article/from-windows-10-linux-ipads-iphones-to-hololens-the-tech-space-station-astronauts-use/|url-status=dead|archive-url=https://web.archive.org/web/20160526014418/https://www.techrepublic.com/article/from-windows-10-linux-ipads-iphones-to-hololens-the-tech-space-station-astronauts-use/|archive-date=26 May 2016|access-date=29 June 2018|work=TechRepublic}} These devices are modified to use the station's 28V DC power system and with additional ventilation since heat generated by the devices can stagnate in the weightless environment. NASA prefers to keep a high commonality between laptops and spare parts are kept on the station so astronauts can repair laptops when needed.{{Cite web|last1=Zell|first1=Martin|last2=Suenson|first2=Rosita|date=13 August 2013|title=ESA ISS Science & System – Operations Status Report #150 Increment 36: 13–26 July 2013|url=https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Columbus/ESA_ISS_Science_System_-_Operations_Status_Report_150_Increment_36_13_26_July_2013|url-status=live|archive-url=https://web.archive.org/web/20230812203259/https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Columbus/ESA_ISS_Science_System_-_Operations_Status_Report_150_Increment_36_13_26_July_2013|archive-date=12 August 2023|access-date=11 July 2018|publisher=European Space Agency}}

The laptops are divided into two groups: the Portable Computer System (PCS) and Station Support Computers (SSC).

PCS laptops run Linux and are used for connecting to the station's primary Command & Control computer (C&C MDM), which runs on Debian Linux,{{Cite news|last=Thomson|first=Iain|date=10 May 2013|title=Penguins in spa-a-a-ce! ISS dumps Windows for Linux on laptops|url=https://www.theregister.co.uk/2013/05/10/iss_linux_debian_deployment/|url-status=live|archive-url=https://web.archive.org/web/20230811162138/https://www.theregister.com/2013/05/10/iss_linux_debian_deployment/|archive-date=11 August 2023|access-date=15 May 2013|work=The Register}} a switch made from Windows in 2013 for reliability and flexibility.{{Cite news|last=Gunter|first=Joel|date=10 May 2013|title=International Space Station to boldly go with Linux over Windows|url=https://www.telegraph.co.uk/technology/news/10049444/International-Space-Station-to-boldly-go-with-Linux-over-Windows.html|url-access=subscription|url-status=live|archive-url=https://ghostarchive.org/archive/20220110/https://www.telegraph.co.uk/technology/news/10049444/International-Space-Station-to-boldly-go-with-Linux-over-Windows.html|archive-date=10 January 2022|access-date=15 May 2013|work=The Daily Telegraph}}{{cbignore}} The primary computer supervises the critical systems that keep the station in orbit and supporting life. Since the primary computer has no display or keyboards, astronauts use a PCS laptop to connect as remote terminals via a USB to 1553 adapter.{{Cite web|last=Keeter|first=Bill|date=30 April 2019|title=April 2019 – ISS On-Orbit Status Report|url=https://blogs.nasa.gov/stationreport/2019/04/|url-status=live|archive-url=https://web.archive.org/web/20230810144500/https://blogs.nasa.gov/stationreport/2019/04/|archive-date=10 August 2023|access-date=5 November 2021|website=blogs.nasa.gov|publisher=NASA}} The primary computer experienced failures in 2001,{{Cite news|last=Burt|first=Julie|date=1 June 2001|title=Computer problems overcome during STS-100|url=https://www.jsc.nasa.gov/history/roundups/issues/2001-06-01.pdf|url-status=dead|archive-url=https://web.archive.org/web/20161223230857/http://www.jsc.nasa.gov/history/roundups/issues/2001-06-01.pdf|archive-date=23 December 2016|access-date=11 July 2018|work=Space Center Roundup|publisher=NASA}} 2007,{{Cite news|last=Klotz|first=Irene|date=13 June 2007|title=NASA battles failure of space station computer|url=https://www.reuters.com/article/us-space-shuttle/nasa-battles-failure-of-space-station-computer-idUSN1337907120070614/|url-status=live|archive-url=https://web.archive.org/web/20230810131847/https://www.reuters.com/article/us-space-shuttle/nasa-battles-failure-of-space-station-computer-idUSN1337907120070614|archive-date=10 August 2023|access-date=11 July 2018|work=Reuters}} and 2017. The 2017 failure required a spacewalk to replace external components.{{Cite news|last=Klotz|first=Irene|date=22 May 2017|title=NASA Plans Emergency Spacewalk To Replace Key Computer on International Space Station|url=https://www.huffingtonpost.com/entry/iss-computer-failure-spacewalk_us_5922759ce4b03b485cb27a80|url-status=live|archive-url=https://web.archive.org/web/20230811165009/https://www.huffpost.com/entry/iss-computer-failure-spacewalk_n_5922759ce4b03b485cb27a80|archive-date=11 August 2023|access-date=11 July 2018|work=Huffpost|agency=Reuters}}

SSC laptops are used for everything else on the station, including reviewing procedures, managing scientific experiments, communicating over e-mail or video chat, and for entertainment during downtime. SSC laptops connect to the station's wireless LAN via Wi-Fi, which connects to the ground via the K_u band. While originally this provided speeds of 10 Mbit/s download and 3 Mbit/s upload from the station,{{Cite news|last=Smith|first=Will|date=19 October 2012|title=How Fast is the ISS's Internet? (and Other Space Questions Answered)|url=http://www.tested.com/science/space/449539-how-fast-isss-internet-and-other-space-questions-answered/|url-status=dead|archive-url=https://web.archive.org/web/20140429212053/http://www.tested.com/science/space/449539-how-fast-isss-internet-and-other-space-questions-answered/|archive-date=29 April 2014|access-date=29 April 2014|work=Tested.com}} NASA upgraded the system in 2019 and increased the speeds to 600 Mbit/s.{{Cite news|last=Williams|first=Matt|date=25 August 2019|title=Upgraded ISS Now Has a 600 Megabit per Second Internet Connection|url=https://www.universetoday.com/143221/upgraded-iss-now-has-a-600-megabit-per-second-internet-connection/|url-status=live|archive-url=https://web.archive.org/web/20230906210636/https://www.universetoday.com/143221/upgraded-iss-now-has-a-600-megabit-per-second-internet-connection/|archive-date=6 September 2023|access-date=23 June 2020|work=Universe Today}} ISS crew members have access to the internet.{{Cite web|last1=Kuksov|first1=Igor|date=13 September 2019|title=Internet in space: Is there Net on Mars?|url=https://www.kaspersky.co.uk/blog/internet-in-space/16690/|url-status=live|archive-url=https://web.archive.org/web/20230831095806/https://www.kaspersky.co.uk/blog/internet-in-space/16690/|archive-date=31 August 2023|access-date=5 December 2022|website=Kaspersky Daily|publisher=Kaspersky Lab}}{{Cite news|date=26 August 2019|title=The ISS Now Has Better Internet Than Most of Us After Its Latest Upgrade|url=https://www.sciencealert.com/the-iss-now-has-better-internet-than-most-of-us-after-its-latest-upgrade|url-status=live|archive-url=https://web.archive.org/web/20231102150646/https://www.sciencealert.com/the-iss-now-has-better-internet-than-most-of-us-after-its-latest-upgrade|archive-date=2 November 2023|access-date=5 December 2022|work=ScienceAlert}}

{{See also|List of International Space Station expeditions}}

{{multiple image

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| image1 = Sts088-703-019e.jpg

| caption1 = Zarya and Unity were entered for the first time on 10 December 1998.

| image2 = Soyuz tm-31 transported to launch pad.jpg

| caption2 = Soyuz TM-31 being prepared to bring the first resident crew to the station in October 2000

}}

Each permanent crew is given an expedition number. Expeditions run up to six months, from launch until undocking, an 'increment' covers the same time period, but includes cargo spacecraft and all activities. Expeditions 1 to 6 consisted of three-person crews. After the destruction of NASA's Space Shuttle Columbia, Expeditions 7 to 12 were reduced to two-person "caretaker" crews who could maintain the station, because a larger crew could not be fully resupplied by the small Russian Progress cargo spacecraft.{{Cite news|last=Harwood|first=William|date=27 February 2003|title=O'Keefe says station set for two-man caretaker crew|url=https://spaceflightnow.com/shuttle/sts107/030227station/|access-date=5 November 2024|work=Spaceflight Now|publisher=CBS News}} After the Shuttle fleet returned to flight, three person crews also returned to the ISS beginning with Expedition 13. As the Shuttle flights expanded the station, crew sizes also expanded, eventually reaching six around 2010.{{cite web|date=10 April 2009|title=International Space Station Expeditions|url=http://www.nasa.gov/mission_pages/station/expeditions/index.html|access-date=13 April 2009|publisher=NASA|archive-date=14 August 2011|archive-url=https://web.archive.org/web/20110814024250/http://www.nasa.gov/mission_pages/station/expeditions/index.html|url-status=dead}}{{cite web|last=NASA|year=2008|title=International Space Station|url=http://www.nasa.gov/mission_pages/station/main/index.html|access-date=22 October 2008|publisher=NASA|archive-date=7 September 2005|archive-url=https://web.archive.org/web/20050907073730/http://www.nasa.gov/mission_pages/station/main/index.html|url-status=live}} With the arrival of crew on larger US commercial spacecraft beginning in 2020,{{Cite news|url=https://www.bbc.co.uk/news/science-environment-51169705|title=SpaceX completes emergency crew escape manoeuvre|date=19 January 2020|url-status=live|archive-url=https://web.archive.org/web/20230811163510/https://www.bbc.com/news/science-environment-51169705|archive-date=11 August 2023|publisher=BBC News}} crew size has been increased to seven, the number for which ISS was originally designed.{{Cite magazine|last=Morring|first=Frank|date=27 July 2012|title=ISS Research Hampered By Crew Availability|url=http://www.aviationweek.com/article.aspx?id=/article-xml/asd_07_26_2012_p01-02-480253.xml|url-status=dead|magazine=Aviation Week|archive-url=https://web.archive.org/web/20130501214851/http://www.aviationweek.com/article.aspx?id=%2Farticle-xml%2Fasd_07_26_2012_p01-02-480253.xml|archive-date=1 May 2013|access-date=30 July 2012|quote=A commercial capability would allow the station's crew to grow from six to seven by providing a four-seat vehicle for emergency departures in addition to the three-seat Russian Soyuz capsules in use today.}}{{Cite magazine|url=https://www.smithsonianmag.com/air-space-magazine/assembly-nearly-complete-2091210/|title=Assembly (Nearly) Complete|last=Hoversten|first=Paul|date=April 2011|publisher=Smithsonian Institution|access-date=8 May 2011|url-status=live|archive-url=https://web.archive.org/web/20230607224549/https://www.smithsonianmag.com/air-space-magazine/assembly-nearly-complete-2091210/|archive-date=7 June 2023|quote=In fact, we're designed on the U.S. side to take four crew. The ISS design is actually for seven. We operate with six because first, we can get all our work done with six, and second, we don't have a vehicle that allows us to fly a seventh crew member. Our requirement for the new vehicles being designed is for four seats. So I don't expect us to go down in crew size. I would expect us to increase it.|magazine=Air & Space}}

Oleg Kononenko of Roscosmos holds the record for the longest time spent in space and at the ISS, accumulating nearly 1,111 days in space over the course of five long-duration missions on the ISS (Expedition 17, 30/31, 44/45, 57/58/59 and 69/70/71). He also served as commander three times (Expedition 31, 58/59 and 70/71).{{Cite web|title=Cosmonaut Biography: Oleg D. Kononenko|url=http://spacefacts.de/bios/cosmonauts/english/kononenko_oleg_d.htm|access-date=5 November 2024|website=spacefacts.de}}

Peggy Whitson of NASA and Axiom Space has spent the most time in space of any American, accumulating over 675 days in space during her time on Expeditions 5, 16, and 50/51/52 and Axiom Mission 2.{{cite web|title=Biographies of U.S. Astronauts: Whitson|url=http://www.spacefacts.de/bios/astronauts/english/whitson_peggy.htm|url-status=live|archive-url=https://web.archive.org/web/20230618112418/http://www.spacefacts.de/bios/astronauts/english/whitson_peggy.htm|archive-date=18 June 2023|access-date=18 June 2023|publisher=Spacefacts}}{{Cite press release|url=https://www.axiomspace.com/press-release/ax2|title=Record-holding astronaut Peggy Whitson and mission pilot John Shoffner to lead Axiom Space's Ax-2 mission to enable new research in space|date=25 May 2021|publisher=Axiom Space|url-status=live|archive-url=https://web.archive.org/web/20231111164639/https://www.axiomspace.com/press-release/ax2|archive-date=11 November 2023}}

{{see also|Space tourism}}

File:Boarding Pass - Kennedy Space Center 39A.png

Travellers who pay for their own passage into space are termed spaceflight participants by Roscosmos and NASA, and are sometimes referred to as "space tourists", a term they generally dislike.{{efn|Privately funded travellers who have objected to the term include Dennis Tito, the first such traveller,Associated Press, 8 May 2001 Mark Shuttleworth, founder of Ubuntu,Associated Press, The Spokesman Review, 6 January 2002, p. A4 Gregory Olsen and Richard Garriott.{{Cite news|last=Schwartz|first=John|date=10 October 2008|title=Russia Leads Way in Space Tourism With Paid Trips into Orbit|work=The New York Times|url=https://www.nytimes.com/2008/10/11/science/space/11space.html|url-status=live|archive-url=https://web.archive.org/web/20160722130339/https://www.nytimes.com/2008/10/11/science/space/11space.html|archive-date=22 July 2016}}{{Cite news|url=https://www.nbcnews.com/id/wbna9323509|title=Space passenger Olsen to pull his own weight|last=Boyle|first=Alan|date=13 September 2005|url-status=live|archive-url=https://web.archive.org/web/20230812203905/https://www.nbcnews.com/id/wbna9323509|archive-date=12 August 2023|publisher=NBC News}} Canadian astronaut Bob Thirsk said the term does not seem appropriate, referring to his crewmate, Guy Laliberté, founder of Cirque du Soleil.{{cite web|title=Flight to space ignited dreams | St. Catharines Standard|url=http://www.stcatharinesstandard.ca/ArticleDisplay.aspx?e=1975186&archive=true|url-status=dead|archive-url=https://archive.today/20120912062200/http://www.stcatharinesstandard.ca/ArticleDisplay.aspx?e=1975186&archive=true|archive-date=12 September 2012|access-date=1 May 2012|publisher=Stcatharinesstandard.ca}} Anousheh Ansari denied being a tourist{{Cite web|url=https://www.esa.int/Applications/Technology_Transfer/I_am_NOT_a_tourist|title=I am NOT a tourist|date=16 February 2007|publisher=European Space Agency|access-date=1 May 2012|url-status=live|archive-url=https://web.archive.org/web/20231126165131/https://www.esa.int/Applications/Technology_Transfer/I_am_NOT_a_tourist|archive-date=26 November 2023}} and took offence at the term.{{Cite news|url=https://www.space.com/2889-interview-anousheh-ansari-female-space-tourist.html|title=Interview with Anousheh Ansari, the First Female Space Tourist|last=Goudarzi|first=Sara|date=15 September 2006|access-date=1 May 2012|url-status=live|archive-url=https://web.archive.org/web/20230811174719/https://www.space.com/2889-interview-anousheh-ansari-female-space-tourist.html|archive-date=11 August 2023|work=Space.com}}}} {{As of|2023|06}}, thirteen space tourists have visited the ISS; nine were transported to the ISS on Russian Soyuz spacecraft, and four were transported on American SpaceX Dragon 2 spacecraft. For one-tourist missions, when professional crews change over in numbers not divisible by the three seats in a Soyuz, and a short-stay crewmember is not sent, the spare seat is sold by MirCorp through Space Adventures. Space tourism was halted in 2011 when the Space Shuttle was retired and the station's crew size was reduced to six, as the partners relied on Russian transport seats for access to the station. Soyuz flight schedules increased after 2013, allowing five Soyuz flights (15 seats) with only two expeditions (12 seats) required.{{Cite news|url=https://spaceflightnow.com/news/n1101/12soyuz/|title=Resumption of Soyuz tourist flights announced|last=Harwood|first=William|date=12 January 2011|access-date=1 May 2012|url-status=live|archive-url=https://web.archive.org/web/20230810131351/https://spaceflightnow.com/news/n1101/12soyuz/|archive-date=10 August 2023|work=Spaceflight Now for CBS News}} The remaining seats were to be sold for around US$40 million each to members of the public who could pass a medical exam. ESA and NASA criticised private spaceflight at the beginning of the ISS, and NASA initially resisted training Dennis Tito, the first person to pay for his own passage to the ISS.{{efn|ESA director Jörg Feustel-Büechl said in 2001 that Russia had no right to send 'amateurs' to the ISS. A 'stand-off' occurred at the Johnson Space Center between Commander Talgat Musabayev and NASA manager Robert Cabana who refused to train Dennis Tito, a member of Musabayev's crew along with Yuri Baturin. Musabayev argued that Tito had trained 700 hours in the last year and was as qualified as any NASA astronaut, and refused to allow his crew to be trained on the USOS without Tito. Cabana would not allow training to begin, and the commander returned with his crew to their hotel.}}

Anousheh Ansari became the first self-funded woman to fly to the ISS as well as the first Iranian in space. Officials reported that her education and experience made her much more than a tourist, and her performance in training had been "excellent."{{Cite news|url=https://www.rferl.org/a/1071358.html|title=U.S.: Iranian-American To Be First Female Civilian in Space|last=Maher|first=Heather|date=15 September 2006|publisher=Radio Free Europe/Radio Liberty|access-date=1 May 2012|url-status=live|archive-url=https://web.archive.org/web/20230906105719/https://www.rferl.org/a/1071358.html|archive-date=6 September 2023}} She did Russian and European studies involving medicine and microbiology during her 10-day stay. The 2009 documentary Space Tourists follows her journey to the station, where she fulfilled "an age-old dream of man: to leave our planet as a 'normal person' and travel into outer space."{{Cite web|title=Space Tourists – A Film By Christian Frei|url=http://www.space-tourists-film.com/en/film_synopsis.php|url-status=live|archive-url=https://web.archive.org/web/20230810130847/http://www.space-tourists-film.com/en/film_synopsis.php|archive-date=10 August 2023|access-date=1 May 2012|publisher=Space-tourists-film.com}}

In 2008, spaceflight participant Richard Garriott placed a geocache aboard the ISS during his flight.{{cite web|title=Geocaching – The Official Global GPS Cache Hunt Site|url=http://www.geocaching.com/|website=geocaching.com|access-date=27 February 2013|archive-date=2 December 2014|archive-url=https://web.archive.org/web/20141202192741/http://www.geocaching.com/|url-status=live}} This is currently the only non-terrestrial geocache in existence.{{Cite news|url=https://www.geekwire.com/2011/outer-space-ocean-floor-15m-geocaches-counting/|title=From outer space to the ocean floor, Geocaching.com now boasts more than 1.5 million hidden treasures|last=Cook|first=John|date=29 August 2011|access-date=27 February 2013|url-status=live|archive-url=https://web.archive.org/web/20230811163646/https://www.geekwire.com/2011/outer-space-ocean-floor-15m-geocaches-counting/|archive-date=11 August 2023|work=Geekwire.com}} At the same time, the Immortality Drive, an electronic record of eight digitised human DNA sequences, was placed aboard the ISS.{{Cite news|url=https://abcnews.go.com/Technology/story?id=6016448|title=American game designer follows father into orbit|date=12 October 2008|access-date=16 May 2016|url-status=live|archive-url=https://web.archive.org/web/20230810130752/https://abcnews.go.com/Technology/story?id=6016448|archive-date=10 August 2023|publisher=ABC News|location=United States}}

After a 12-year hiatus, the first two wholly space tourism-dedicated private spaceflights to the ISS were undertaken. Soyuz MS-20 launched in December 2021, carrying visiting Roscosmos cosmonaut Alexander Misurkin and two Japanese space tourists under the aegis of the private company Space Adventures;{{Cite web|url=https://spaceadventures.com/experiences/space-station/|title=Space Station Experience|last=Jefferson|first=Mark|date=9 January 2018|publisher=Space Adventures|url-status=live|archive-url=https://web.archive.org/web/20180925164032/http://www.spaceadventures.com:80/experiences/space-station|archive-date=25 September 2018}}{{Cite news|url=https://tass.com/science/1045321|title=Roscosmos signs new contract on flight of two space tourists to ISS|date=19 February 2019|agency=TASS|url-status=live|archive-url=https://web.archive.org/web/20230810132826/https://tass.com/science/1045321|archive-date=10 August 2023}} in April 2022, the company Axiom Space chartered a SpaceX Dragon 2 spacecraft and sent its own employee astronaut Michael Lopez-Alegria and three space tourists to the ISS for Axiom Mission 1,{{Cite news|url=https://www.teslarati.com/spacex-space-tourism-first-crew-dragon-contract/|title=SpaceX space tourism ambitions made real with Crew Dragon's first private contract|last=Ralph|first=Eric|date=9 March 2020|url-status=live|archive-url=https://web.archive.org/web/20230810131652/https://www.teslarati.com/spacex-space-tourism-first-crew-dragon-contract/|archive-date=10 August 2023|work=Teslarati}}{{Cite press release|url=https://www.axiomspace.com/post/axiom-space-plans-first-ever-fully-private-human-spaceflight-mission-to-international-space-station|title=Axiom Space plans first-ever fully private human spaceflight mission to International Space Station|date=5 March 2020|publisher=Axiom Space|url-status=live|archive-url=https://web.archive.org/web/20230812223849/https://www.axiomspace.com/news/axiom-space-plans-first-ever-fully-private-human-spaceflight-mission-to-international-space-station|archive-date=12 August 2023}}{{Cite web|url=https://www.axiomspace.com/missions/ax1|title=Meet Ax-1, The Beginning of a New Era|publisher=Axiom Space|access-date=18 June 2023|url-status=live|archive-url=https://web.archive.org/web/20231124155314/https://www.axiomspace.com/missions/ax1|archive-date=24 November 2023}} followed in May 2023 by one more tourist, John Shoffner, alongside employee astronaut Peggy Whitson and two Saudi astronauts for the Axiom Mission 2.{{Cite news|url=https://www.cnbc.com/2021/06/02/axiom-space-expands-spacex-deal-for-private-crew-launches-to-iss-.html|title=Axiom Space expands SpaceX private crew launch deal, with four total missions to the space station|last=Sheetz|first=Michael|date=2 June 2021|access-date=2 August 2022|url-status=live|archive-url=https://web.archive.org/web/20230529151534/https://www.cnbc.com/2021/06/02/axiom-space-expands-spacex-deal-for-private-crew-launches-to-iss-.html|archive-date=29 May 2023|publisher=CNBC}}{{Cite web|url=https://www.axiomspace.com/missions/ax2|title=Ax-2: The second private mission to the International Space Station|publisher=Axiom Space|access-date=18 June 2023|url-status=live|archive-url=https://web.archive.org/web/20231124155431/https://www.axiomspace.com/missions/ax2|archive-date=24 November 2023}}

Various crewed and uncrewed spacecraft have supported the station's activities. Flights to the ISS include 37 Space Shuttle, 91 Progress,{{Efn|Including the modified DC-1, M-MIM2 and M-UM module transports}} 72 Soyuz, 5 ATV, 9 HTV, 2 Boeing Starliner, 46 SpaceX Dragon{{Efn|Includes both crewed and uncrewed missions}} and 20 Cygnus missions.{{Cite news|url=https://www.space.com/northrop-grumman-heaviest-cygnus-cargo-ship-launch|title=Antares rocket launches heaviest Cygnus cargo ship ever to space station for NASA|last=Thompson|first=Amy|date=10 August 2021|access-date=11 August 2021|url-status=live|archive-url=https://web.archive.org/web/20230405033657/https://www.space.com/northrop-grumman-heaviest-cygnus-cargo-ship-launch|archive-date=5 April 2023|work=Space.com}}

There are currently eight docking ports for visiting spacecraft, with four additional ports installed but not yet put into service:{{Cite conference|url=https://ntrs.nasa.gov/api/citations/20110010964/downloads/20110010964.pdf|title=ISS Interface Mechanisms and their Heritage|last1=Cook|first1=John|last2=Aksamentov|first2=Valery|last3=Hoffman|first3=Thomas|last4=Bruner|first4=Wes|date=September 2011|publisher=Boeing|location=Houston, Texas|access-date=31 March 2015|url-status=live|archive-url=https://web.archive.org/web/20230810133110/https://ntrs.nasa.gov/api/citations/20110010964/downloads/20110010964.pdf|archive-date=10 August 2023|quote=Docking is when one incoming spacecraft rendezvous with another spacecraft and flies a controlled collision trajectory in such a manner so as to align and mesh the interface mechanisms. The spacecraft docking mechanisms typically enter what is called soft capture, followed by a load attenuation phase, and then the hard docked position which establishes an air-tight structural connection between spacecraft. Berthing, by contrast, is when an incoming spacecraft is grappled by a robotic arm and its interface mechanism is placed in close proximity of the stationary interface mechanism. Then typically there is a capture process, coarse alignment and fine alignment and then structural attachment.|conference=AIAA Space}}

1. Harmony forward (with PMA 2 & IDA 2)
2. Harmony zenith (with PMA 3 & IDA 3)
3. Harmony nadir (CBM port)
4. Unity nadir (CBM port)
5. Prichal aft{{Efn|The Prichal aft, forward, port and starboard ports still have their protective covers in place and have yet to be used since the module originally docked at the station.|name=Prichal}}
6. Prichal forward{{Efn|name=Prichal}}
7. Prichal nadir
8. Prichal port{{Efn|name=Prichal}}
9. Prichal starboard{{Efn|name=Prichal}}
10. Poisk zenith
11. Rassvet nadir
12. Zvezda aft

Forward ports are at the front of the station according to its normal direction of travel and orientation (attitude). Aft is at the rear of the station. Nadir is Earth facing, zenith faced away from Earth. Port is to the left if pointing one's feet towards the Earth and looking in the direction of travel and starboard is to the right.

Cargo spacecraft that will perform an orbital re-boost of the station will typically dock at an aft, forward or nadir-facing port.

{{Main|List of human spaceflights to the International Space Station}}

File:Commercial Crew Program vehicles.jpg

{{As of|2024|10|24|url=https://www.nasa.gov/feature/visitors-to-the-station-by-country/}}, 281 people representing 23 countries had visited the space station, many of them multiple times. The United States has sent 167 people, Russia has 61, Japan has sent 11, Canada has sent nine, Italy has sent six, France and Germany have each sent four, Saudi Arabia, Sweden and the United Arab Emirates have each sent two, and there has been one person from Belarus, Belgium, Brazil, Denmark, Israel, Kazakhstan, Malaysia, Netherlands, South Africa, South Korea, Spain, Turkey and the United Kingdom.{{cite web|last=Graf|first=Abby|title=Visitors to the Station by Country|website=NASA|date=24 October 2024|url=https://www.nasa.gov/international-space-station/space-station-visitors-by-country/|access-date=6 November 2024}}

{{Main|Uncrewed spaceflights to the International Space Station}}

Uncrewed spaceflights are made primarily to deliver cargo, however several Russian modules have also docked to the outpost following uncrewed launches. Resupply missions typically use the Russian Progress spacecraft, former European ATVs, Japanese Kounotori vehicles, and the American Dragon and Cygnus spacecraft.

File:ISS 12-04-24.png

All dates are UTC. Departure dates are the earliest possible ({{abbr|NET|not earlier than}}) and may change.

All dates are UTC. Launch dates are the earliest possible ({{abbr|NET|not earlier than}}) and may change.

{{See also|Docking and berthing of spacecraft}}

File:Progress M-14M.jpg resupply vehicle approaching the ISS in 2012. More than 50 unpiloted Progress spacecraft have delivered supplies during the lifetime of the station.]]

The Russian spacecraft and can autonomously rendezvous and dock with the station without human intervention. Once within approximately {{Convert|200|km}}, the spacecraft begins receiving radio signals from the Kurs docking navigation system on the station. As the spacecraft nears the station, laser-based optical equipment precisely aligns the craft with the docking port and controls the final approach. While the crew on the ISS and spacecraft monitor the procedure, their role is primarily supervisory, with intervention limited to issuing abort commands in emergencies. Although initial development costs were substantial, the system's reliability and standardized components have yielded significant cost reductions for subsequent missions.{{Cite journal|last1=Woffinden|first1=David C.|last2=Geller|first2=David K.|date=July 2007|title=Navigating the Road to Autonomous Orbital Rendezvous|journal=Journal of Spacecraft and Rockets|volume=44|issue=4|pages=898–909|bibcode=2007JSpRo..44..898W|doi=10.2514/1.30734}}

The American SpaceX Dragon 2 cargo and crewed spacecraft can autonomously rendezvous and dock with the station without human intervention. However, on crewed Dragon missions, the astronauts have the capability to intervene and fly the vehicle manually.{{Cite web|last=Burghardt|first=Thomas|date=3 March 2019|title=Crew Dragon successfully conducts debut docking with the ISS|url=https://www.nasaspaceflight.com/2019/03/crew-dragon-first-docking-iss-dm1/|access-date=7 August 2024|website=NASASpaceFlight.com}}

File:ISS-36 HTV-4 berthing 2.jpg berthing]]

Other automated cargo spacecraft typically use a semi-automated process when arriving and departing from the station. These spacecraft are instructed to approach and park near the station. Once the crew on board the station is ready, the spacecraft is commanded to come close to the station, so that it can be grappled by an astronaut using the Mobile Servicing System robotic arm. The final mating of the spacecraft to the station is achieved using the robotic arm (a process known as berthing). Spacecraft using this semi-automated process include the American Cygnus and the Japanese HTV-X. The now-retired American SpaceX Dragon 1, European ATV and Japanese HTV also used this process.

Prior to a spacecraft's docking to the ISS, navigation and attitude control (GNC) is handed over to the ground control of the spacecraft's country of origin. GNC is set to allow the station to drift in space, rather than fire its thrusters or turn using gyroscopes. The solar panels of the station are turned edge-on to the incoming spacecraft, so residue from its thrusters does not damage the cells. Before its retirement, Shuttle launches were often given priority over Soyuz, with occasional priority given to Soyuz arrivals carrying crew and time-critical cargoes, such as biological experiment materials.{{cite web|last1=Trinidad|first1=Katherine|last2=Thomas|first2=Candrea|date=22 May 2009|title=NASA's Space Shuttle Landing Delayed by Weather|url=http://www.nasa.gov/home/hqnews/2009/may/HQ_09-118_Shuttle_Landing_Delayed.html|access-date=26 June 2015|publisher=NASA|archive-date=7 March 2016|archive-url=https://web.archive.org/web/20160307235001/http://www.nasa.gov/home/hqnews/2009/may/HQ_09-118_Shuttle_Landing_Delayed.html|url-status=dead}}

{{Main|Maintenance of the International Space Station}}

File:ISS Unpressurized Platforms.png; some are externally stored on pallets called ELCs and ESPs.]]

File:STS-120 EVA Scott Parazynski.jpg during STS-120, astronaut Scott Parazynski performs makeshift repairs to a US solar array that was damaged during unfolding|alt=Two black and orange solar arrays, shown uneven and with a large tear visible. A crew member in a spacesuit, attached to the end of a robotic arm, holds a latticework between two solar sails.]]

File:Astronaut Mike Hopkins on Dec. 24 Spacewalk.jpg during a spacewalk]]

Orbital Replacement Units (ORUs) are spare parts that can be readily replaced when a unit either passes its design life or fails. Examples of ORUs are pumps, storage tanks, controller boxes, antennas, and battery units. Some units can be replaced using robotic arms. Most are stored outside the station, either on small pallets called ExPRESS Logistics Carriers (ELCs) or share larger platforms called External Stowage Platforms (ESPs) which also hold science experiments. Both kinds of pallets provide electricity for many parts that could be damaged by the cold of space and require heating. The larger logistics carriers also have local area network (LAN) connections for telemetry to connect experiments. A heavy emphasis on stocking the USOS with ORU's occurred around 2011, before the end of the NASA shuttle programme, as its commercial replacements, Cygnus and Dragon, carry one tenth to one quarter the payload.

Unexpected problems and failures have impacted the station's assembly time-line and work schedules leading to periods of reduced capabilities and, in some cases, could have forced abandonment of the station for safety reasons. Serious problems include an air leak from the USOS in 2004,{{Cite news|url=https://www.nbcnews.com/id/wbna3882962|title=Crew finds 'culprit' in space station leak|last=Oberg|first=James|date=6 January 2004|access-date=22 August 2010|url-status=live|archive-url=https://web.archive.org/web/20230812204804/https://www.nbcnews.com/id/wbna3882962|archive-date=12 August 2023|publisher=NBC News}} the venting of fumes from an Elektron oxygen generator in 2006,{{Cite news|url=https://spaceflightnow.com/station/exp13/060918elektron.html|title=Oxygen Generator Problem Triggers Station Alarm|last=Harwood|first=William|date=18 September 2006|access-date=24 November 2008|url-status=live|archive-url=https://web.archive.org/web/20230811173756/https://spaceflightnow.com/station/exp13/060918elektron.html|archive-date=11 August 2023|work=Spaceflight Now for CBS News}} and the failure of the computers in the ROS in 2007 during STS-117 that left the station without thruster, Elektron, Vozdukh and other environmental control system operations. In the latter case, the root cause was found to be condensation inside electrical connectors leading to a short circuit.{{Cite news|last=Reindl|first=J. C.|date=4 October 2008|title=University of Toledo alumnus had role in rescue of space station|url=https://www.toledoblade.com/local/education/2008/10/04/University-of-Toledo-alumnus-had-role-in-rescue-of-space-station/stories/200810040061|url-access=subscription|url-status=live|archive-url=https://web.archive.org/web/20230811162936/https://www.toledoblade.com/local/education/2008/10/04/University-of-Toledo-alumnus-had-role-in-rescue-of-space-station/stories/200810040061|archive-date=11 August 2023|access-date=31 July 2019|website=Toledo Blade|location=Toledo, Ohio}}

During STS-120 in 2007 and following the relocation of the P6 truss and solar arrays, it was noted during unfurling that the solar array had torn and was not deploying properly.{{Cite news|url=https://www.redorbit.com/news/space/1123767/astronauts_notice_tear_in_solar_panel|title=Astronauts notice tear in solar panel|last=Savage|first=Sam|date=30 October 2007|access-date=30 October 2007|url-status=live|archive-url=https://web.archive.org/web/20230813201109/https://www.redorbit.com/news/space/1123767/astronauts_notice_tear_in_solar_panel/|archive-date=13 August 2023|agency=Associated Press|work=redOrbit.com}} An EVA was carried out by Scott Parazynski, assisted by Douglas Wheelock. Extra precautions were taken to reduce the risk of electric shock, as the repairs were carried out with the solar array exposed to sunlight.{{Cite news|url=https://www.washingtonpost.com/wp-dyn/content/article/2007/11/03/AR2007110300227.html|title=Space Station's Damaged Panel Is Fixed|last=Stein|first=Rob|date=4 November 2007|access-date=4 November 2007|url-status=live|archive-url=https://web.archive.org/web/20110629024200/http://www.washingtonpost.com/wp-dyn/content/article/2007/11/03/AR2007110300227.html|archive-date=29 June 2011|newspaper=The Washington Post}} The issues with the array were followed in the same year by problems with the starboard Solar Alpha Rotary Joint (SARJ), which rotates the arrays on the starboard side of the station. Excessive vibration and high-current spikes in the array drive motor were noted, resulting in a decision to substantially curtail motion of the starboard SARJ until the cause was understood. Inspections during EVAs on STS-120 and STS-123 showed extensive contamination from metallic shavings and debris in the large drive gear and confirmed damage to the large metallic bearing surfaces, so the joint was locked to prevent further damage.{{Cite news|url=https://spaceflightnow.com/shuttle/sts123/080325sarj/index.html|title=Station chief gives detailed update on joint problem|last=Harwood|first=William|date=25 March 2008|access-date=5 November 2008|url-status=live|archive-url=https://web.archive.org/web/20230811162701/https://spaceflightnow.com/shuttle/sts123/080325sarj/index.html|archive-date=11 August 2023|work=Spaceflight Now for CBS News}}{{Cite conference|url=https://ntrs.nasa.gov/api/citations/20100003841/downloads/20100003841.pdf|title=The International Space Station Solar Alpha Rotary Joint Anomaly Investigation|last1=Harik|first1=Elliot P.|last2=McFatter|first2=Justin|last3=Sweeney|first3=Daniel J.|last4=Enriquez|first4=Carlos F.|last5=Taylor|first5=Deneen M.|last6=McCann|first6=David S.|year=2010|id=JSC-CN-19606|url-status=live|archive-url=https://web.archive.org/web/20230406025937/https://ntrs.nasa.gov/api/citations/20100003841/downloads/20100003841.pdf|archive-date=6 April 2023|display-authors=1|conference=40th Aerospace Mechanisms Symposium. 12–14 May 2010. Cocoa Beach, Florida.}} Repairs to the joints were carried out during STS-126 with lubrication and the replacement of 11 out of 12 trundle bearings on the joint.{{cite web|date=30 October 2008|title=Crew Expansion Prep, SARJ Repair Focus of STS-126|url=http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts126/126_overview.html|access-date=5 November 2008|publisher=NASA|archive-date=28 November 2008|archive-url=https://web.archive.org/web/20081128072943/http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts126/126_overview.html|url-status=dead}}{{Cite news|url=https://spaceflightnow.com/shuttle/sts126/081118fd5/index.html|title=Astronauts prepare for first spacewalk of shuttle flight|last=Harwood|first=William|date=18 November 2008|access-date=22 November 2008|url-status=live|archive-url=https://web.archive.org/web/20230810131509/https://spaceflightnow.com/shuttle/sts126/081118fd5/index.html|archive-date=10 August 2023|work=Spaceflight Now for CBS News}}

In September 2008, damage to the S1 radiator was first noticed in Soyuz imagery. The problem was initially not thought to be serious.{{Cite news|url=https://www.nasaspaceflight.com/2009/04/iss-concern-s1-radiator-may-require-replacement-shuttle-mission/|title=ISS concern over S1 Radiator – may require replacement via shuttle mission|last=Bergin|first=Chris|date=1 April 2009|access-date=3 April 2009|url-status=live|archive-url=https://web.archive.org/web/20230811165211/https://www.nasaspaceflight.com/2009/04/iss-concern-s1-radiator-may-require-replacement-shuttle-mission/|archive-date=11 August 2023|work=NASASpaceFlight.com}} The imagery showed that the surface of one sub-panel had peeled back from the underlying central structure, possibly because of micro-meteoroid or debris impact. On 15 May 2009, the damaged radiator panel's ammonia tubing was mechanically shut off from the rest of the cooling system by the computer-controlled closure of a valve. The same valve was then used to vent the ammonia from the damaged panel, eliminating the possibility of an ammonia leak. It is also known that a Service Module thruster cover struck the S1 radiator after being jettisoned during an EVA in 2008, but its effect, if any, has not been determined.

In the early hours of 1 August 2010, a failure in cooling Loop A (starboard side), one of two external cooling loops, left the station with only half of its normal cooling capacity and zero redundancy in some systems.{{Cite news|url=https://spaceflightnow.com/news/n1007/31station/|title=Spacewalks needed to fix station cooling problem|last=Harwood|first=William|date=31 July 2010|access-date=16 November 2010|url-status=live|archive-url=https://web.archive.org/web/20230811162357/https://spaceflightnow.com/news/n1007/31station/|archive-date=11 August 2023|work=Spaceflight Now for CBS News}}{{Cite press release|url=https://www.nasa.gov/directorates/heo/reports/iss_reports/2010/08012010.html|title=ISS On-Orbit Status 08/01/10|date=June 2023|publisher=NASA|access-date=16 November 2010|url-status=dead|archive-url=https://web.archive.org/web/20230917233416/https://www.nasa.gov/directorates/heo/reports/iss_reports/2010/08012010.html|archive-date=17 September 2023}}{{cite web|date=21 November 2006|title=International Space Station Active Thermal Control System|url=http://www.boeing.com/defense-space/space/spacestation/systems/atcs.html|url-status=dead|archive-url=https://web.archive.org/web/20100330004837/http://www.boeing.com/defense-space/space/spacestation/systems/atcs.html|archive-date=30 March 2010|access-date=16 November 2010|publisher=Boeing}} The problem appeared to be in the ammonia pump module that circulates the ammonia cooling fluid. Several subsystems, including two of the four CMGs, were shut down.

Planned operations on the ISS were interrupted through a series of EVAs to address the cooling system issue. A first EVA on 7 August 2010, to replace the failed pump module, was not fully completed because of an ammonia leak in one of four quick-disconnects. A second EVA on 11 August removed the failed pump module.{{Cite news|url=https://spaceflightnow.com/station/exp24/100810evapre/|title=Wednesday spacewalk to remove failed coolant pump|last=Harwood|first=William|date=10 August 2010|url-status=live|archive-url=https://web.archive.org/web/20230810131919/https://spaceflightnow.com/station/exp24/100810evapre/|archive-date=10 August 2023|work=Spaceflight Now for CBS News}}{{Cite news|url=https://www.nasaspaceflight.com/2010/08/live-second-eva-with-pump-module-changeout/|title=Large success for second EVA as failed Pump Module is removed|last=Gebhardt|first=Chris|date=11 August 2010|url-status=live|archive-url=https://web.archive.org/web/20230810132125/https://www.nasaspaceflight.com/2010/08/live-second-eva-with-pump-module-changeout/|archive-date=10 August 2023|work=NASASpaceFlight.com}} A third EVA was required to restore Loop A to normal functionality.{{Cite news|url=https://spaceflightnow.com/station/exp24/100811eva2/index5.html|title=Station's bad pump removed; more spacewalking ahead|last=Harwood|first=William|date=11 August 2010|url-status=live|archive-url=https://web.archive.org/web/20230810133016/https://spaceflightnow.com/station/exp24/100811eva2/index5.html|archive-date=10 August 2023|work=Spaceflight Now for CBS News}}{{Cite news|url=https://www.nasaspaceflight.com/2010/08/iss-cooling-returning-normal-confirming-etcs-pm-success/|title=ISS cooling configuration returning to normal confirming ETCS PM success|last=Bergin|first=Chris|date=18 August 2010|url-status=live|archive-url=https://web.archive.org/web/20101024194307/https://www.nasaspaceflight.com/2010/08/iss-cooling-returning-normal-confirming-etcs-pm-success/|archive-date=24 October 2010|work=NASASpaceFlight.com}}

The USOS's cooling system is largely built by the US company Boeing,{{Cite news|url=https://www.space.com/8865-cooling-system-malfunction-highlights-space-station-complexity.html|title=Cooling System Malfunction Highlights Space Station's Complexity|last=Chow|first=Denise|date=2 August 2010|url-status=live|archive-url=https://web.archive.org/web/20230811162718/https://www.space.com/8865-cooling-system-malfunction-highlights-space-station-complexity.html|archive-date=11 August 2023|work=Space.com}} which is also the manufacturer of the failed pump.

The four Main Bus Switching Units (MBSUs, located in the S0 truss), control the routing of power from the four solar array wings to the rest of the ISS. Each MBSU has two power channels that feed 160V DC from the arrays to two DC-to-DC power converters (DDCUs) that supply the 124V power used in the station. In late 2011, MBSU-1 ceased responding to commands or sending data confirming its health. While still routing power correctly, it was scheduled to be swapped out at the next available EVA. A spare MBSU was already on board, but a 30 August 2012 EVA failed to be completed when a bolt being tightened to finish installation of the spare unit jammed before the electrical connection was secured.{{Cite news|url=https://www.nasaspaceflight.com/2012/08/astronaut-perform-first-post-shuttle-spacewalk-iss|title=Astronaut duo complete challenging first post-Shuttle US spacewalk on ISS|last=Harding|first=Pete|date=30 August 2012|access-date=22 October 2013|url-status=live|archive-url=https://web.archive.org/web/20230811162809/https://www.nasaspaceflight.com/2012/08/astronaut-perform-first-post-shuttle-spacewalk-iss/|archive-date=11 August 2023|work=NASASpaceFlight.com}} The loss of MBSU-1 limited the station to 75% of its normal power capacity, requiring minor limitations in normal operations until the problem could be addressed.

On 5 September 2012, in a second six-hour EVA, astronauts Sunita Williams and Akihiko Hoshide successfully replaced MBSU-1 and restored the ISS to 100% power.{{Cite news|url=https://spaceref.com/space-stations/critical-space-station-spacewalk-a-success/|title=Critical Space Station Spacewalk a Success|last=Boucher|first=Marc|date=5 September 2012|work=SpaceRef}}

On 24 December 2013, astronauts installed a new ammonia pump for the station's cooling system. The faulty cooling system had failed earlier in the month, halting many of the station's science experiments. Astronauts had to brave a "mini blizzard" of ammonia while installing the new pump. It was only the second Christmas Eve spacewalk in NASA history.{{Cite news|date=24 December 2013|title=Astronauts Complete Rare Christmas Eve Spacewalk|work=Leaker|agency=Associated Press|url=http://www.leaker.com/astronauts-complete-rare-christmas-eve-spacewalk/|url-status=dead|access-date=24 December 2013|archive-url=https://web.archive.org/web/20131226025635/http://www.leaker.com/astronauts-complete-rare-christmas-eve-spacewalk/|archive-date=26 December 2013}}

{{main|International Space Station programme#Mission control centres}}

The components of the ISS are operated and monitored by their respective space agencies at mission control centres across the globe, primarily the Christopher C. Kraft Jr. Mission Control Center in Houston and the RKA Mission Control Center (TsUP) in Moscow, with support from Tsukuba Space Center in Japan, Payload Operations and Integration Center in Huntsville, Alabama, U.S., Columbus Control Center in Munich, Germany and Mobile Servicing System Control at the Canadian Space Agency's headquarters in Saint-Hubert, Quebec.

File:Nikolai Budarin in a sleep station in Zvezda.jpg at work inside the Zvezda service module crew quarters]]The living and working space aboard the International Space Station (ISS) is larger than a six-bedroom house, equipped with seven private sleeping quarters, three bathrooms, two dining rooms, a gym, and a panoramic 360-degree-view bay window.{{Cite web |last=Howell |first=Elizabeth |date=24 August 2022 |title=International Space Station: Facts, History & Tracking |url=https://www.space.com/16748-international-space-station.html |url-status=live |archive-url=https://web.archive.org/web/20190401024329/https://www.space.com/16748-international-space-station.html |archive-date=1 April 2019 |access-date=27 April 2024 |website=Space.com}}

The station provides dedicated crew quarters for long-term crew members. Two "sleep stations" are located in the Zvezda module, one in Nauka, and four in Harmony.{{Cite web |date=11 August 2021 |title=Новости. Космонавт рассказал, кто может первым заселиться в модуль "Наука" на МКС |trans-title=A cosmonaut explained who can be the first to settle in the 'Nauka' module on the ISS |url=https://www.roscosmos.ru/32150/ |url-status=dead |archive-url=https://web.archive.org/web/20220822052138/https://www.roscosmos.ru/32150/ |archive-date=22 August 2022 |access-date=12 August 2021 |publisher=Roscosmos |language=ru}}{{cite web |date=6 December 2010 |title=At Home with Commander Scott Kelly (Video) |url=https://www.youtube.com/watch?v=Q4dG9vSyUFQ |url-status=live |archive-url=https://ghostarchive.org/varchive/youtube/20211211/Q4dG9vSyUFQ |archive-date=11 December 2021 |access-date=8 May 2011 |publisher=NASA |location=International Space Station}}{{cbignore}}{{Cite web |title=Nauka module prelaunch booklet |url=https://www.roscosmos.ru/media/files/nauka.pdf |url-status=dead |archive-url=https://web.archive.org/web/20220822181356/https://www.roscosmos.ru/media/files/nauka.pdf |archive-date=22 August 2022 |publisher=Roscosmos}}{{Cite conference |last1=Broyan |first1=James Lee |last2=Borrego |first2=Melissa Ann |last3=Bahr |first3=Juergen F. |year=2008 |title=International Space Station USOS Crew Quarters Development |url=https://ntrs.nasa.gov/api/citations/20080013462/downloads/20080013462.pdf |conference=International Conference on Environmental Systems |location=San Francisco, California |publisher=SAE International |volume=38 |id=08ICES-0222 |archive-url=https://web.archive.org/web/20231118224703/https://ntrs.nasa.gov/api/citations/20080013462/downloads/20080013462.pdf |archive-date=18 November 2023 |access-date=8 May 2011 |url-status=live}} These soundproof, person-sized booths offer privacy, ventilation, and basic amenities such as a sleeping bag, a reading lamp, a desktop, a shelf, and storage for personal items.{{Cite web |date=19 July 2004 |title=Daily life |url=https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Astronauts/Daily_life |url-status=live |archive-url=https://web.archive.org/web/20230812210927/https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Astronauts/Daily_life |archive-date=12 August 2023 |access-date=28 October 2009 |publisher=European Space Agency}}{{cite web |last=Mansfield |first=Cheryl L. |date=7 November 2008 |title=Station Prepares for Expanding Crew |url=http://www.nasa.gov/mission_pages/station/behindscenes/126_payload.html |url-status=dead |archive-url=https://web.archive.org/web/20081204054653/http://www.nasa.gov/mission_pages/station/behindscenes/126_payload.html |archive-date=4 December 2008 |access-date=17 September 2009 |publisher=NASA}}{{cite web |title=Living and Working on the International Space Station |url=http://www.asc-csa.gc.ca/pdf/educator-liv_wor_iss.pdf |url-status=dead |archive-url=https://web.archive.org/web/20090419045323/http://www.asc-csa.gc.ca/pdf/educator-liv_wor_iss.pdf |archive-date=19 April 2009 |access-date=28 October 2009 |publisher=CSA}} The quarters in Zvezda include a small window but have less ventilation and soundproofing.

Visiting crew members use tethered sleeping bags attached to available wall space. While it is possible to sleep floating freely, this is generally avoided to prevent collisions with sensitive equipment.{{Cite news |last=Malik |first=Tariq |date=27 July 2009 |title=Sleeping in Space is Easy, But There's No Shower |url=https://www.space.com/7060-sleeping-space-easy-shower.html |url-status=live |archive-url=https://web.archive.org/web/20230812222844/https://www.space.com/7060-sleeping-space-easy-shower.html |archive-date=12 August 2023 |access-date=29 October 2009 |work=Space.com}} Proper ventilation is critical, as astronauts risk oxygen deprivation if exhaled carbon dioxide accumulates in a bubble around their heads.

The station’s lighting system is adjustable, allowing for dimming, switching off, and colour temperature changes to support crew activities and rest.{{Cite AV media |url=https://www.youtube.com/watch?v=yNgMzNN23kE |title=Bedtime in space |time={{time needed|date=September 2019}} |access-date=21 September 2019 |archive-url=https://ghostarchive.org/varchive/youtube/20211211/yNgMzNN23kE |archive-date=11 December 2021 |url-status=live |via=YouTube}}{{cbignore}}{{Cite web |date=13 December 2018 |title=STEMonstrations: Sleep Science |url=https://images.nasa.gov/details-jsc2018m000902-STEMonstrations_Sleep_Science_MP4 |url-status=live |archive-url=https://web.archive.org/web/20231125172450/https://images.nasa.gov/details-jsc2018m000902-STEMonstrations_Sleep_Science_MP4 |archive-date=25 November 2023 |access-date=13 June 2020 |website=NASA Image and Video Library |publisher=NASA |format=AV media |id=jsc2018m000902-STEMonstrations_Sleep_Science_MP4}}

File:Exp18home nasa big.jpg looking out of a window|left]]

The ISS operates on Coordinated Universal Time (UTC).{{Cite magazine |last=Mitchell |first=Gareth |title=What time zone do they use on the International Space Station? |url=https://www.sciencefocus.com/space/what-time-zone-do-they-use-on-the-international-space-station/ |url-status=live |archive-url=https://web.archive.org/web/20230324101052/https://www.sciencefocus.com/space/what-time-zone-do-they-use-on-the-international-space-station/ |archive-date=24 March 2023 |access-date=26 May 2021 |magazine=BBC Science Focus}} A typical day aboard the ISS begins at 06:00 with wake-up, post-sleep routines, and a morning inspection of the station. After breakfast, the crew holds a daily planning conference with Mission Control, starting work around 08:10. Morning tasks include scheduled exercise, scientific experiments, maintenance, or operational duties. Following a one-hour lunch break at 13:05, the crew resumes their afternoon schedule of work and exercise. Pre-sleep activities, including dinner and a crew conference, begin at 19:30, with the scheduled sleep period starting at 21:30.{{cite web |date=5 November 2008 |title=ISS Crew Timeline |url=http://www.nasa.gov/pdf/287386main_110508_tl.pdf |url-status=dead |archive-url=https://web.archive.org/web/20160730044854/http://www.nasa.gov/pdf/287386main_110508_tl.pdf |archive-date=30 July 2016 |access-date=5 November 2008 |publisher=NASA}}

The crew works approximately 10 hours on weekdays and 5 hours on Saturdays, with the remaining time allocated for relaxation or catching up on tasks. Free time often involves enjoying personal hobbies, communicating with family, or gazing out at Earth through the station’s windows. The crew can watch TV aboard the station.{{Cite news |last=Novak |first=Matt |date=4 August 2024 |title=Every TV Show Astronauts Can Watch on the ISS Right Now |url=https://gizmodo.com/every-tv-show-astronauts-can-watch-on-the-iss-right-now-1851567279 |access-date=13 February 2025 |work=Gizmodo |type=Digital}}

When the Space Shuttle was operating, the ISS crew aligned with the shuttle crew's Mission Elapsed Time, a flexible schedule based on the shuttle's launch.{{cite web |title=NASA – Time in Space, A Space in Time |url=https://www.nasa.gov/mission_pages/station/research/news/time_in_space.html |url-status=dead |archive-url=https://web.archive.org/web/20150420050836/http://www.nasa.gov/mission_pages/station/research/news/time_in_space.html |archive-date=20 April 2015 |access-date=5 May 2015 |website=nasa.gov}}{{cite web |date=17 March 2013 |title=A Slice of Time Pie |url=http://blogs.nasa.gov/cm/blog/ISS%20Science%20Blog/posts/post_1340820317951.html |url-status=dead |archive-url=https://web.archive.org/web/20130317075600/http://blogs.nasa.gov/cm/blog/ISS%20Science%20Blog/posts/post_1340820317951.html |archive-date=17 March 2013 |access-date=5 May 2015}}{{cite web |title=Human Space Flight (HSF) – Crew Answers |url=http://spaceflight.nasa.gov/feedback/expert/answer/crew/sts-113/index_2.html |url-status=dead |archive-url=https://web.archive.org/web/20110721054011/http://spaceflight.nasa.gov/feedback/expert/answer/crew/sts-113/index_2.html |archive-date=21 July 2011 |access-date=5 May 2015 |website=spaceflight.nasa.gov}}

To simulate night conditions, the station’s windows are covered during designated sleep periods, as the ISS experiences 16 sunrises and sunsets daily due to its orbital speed.

Reflection of individual and crew characteristics are found particularly in the decoration of the station and expressions in general, such as religion.{{cite web|last=Archaeology|first=ISS|title=Religious life on ISS|website=ISS Archaeology|date=11 November 2017|url=https://issarchaeology.org/religious-life-on-iss/|access-date=22 July 2024}} The latter has produced a certain material economy between the station and Russia in particular.{{cite journal|last1=Salmond|first1=Wendy|last2=Walsh|first2=Justin|last3=Gorman|first3=Alice|title=Eternity in Low Earth Orbit: Icons on the International Space Station|journal=Religions|volume=11|issue=11|date=17 November 2020|issn=2077-1444|doi=10.3390/rel11110611|doi-access=free|page=611}}

The micro-society of the station, as well as wider society, and possibly the emergence of distinct station cultures,{{cite journal|last1=Walsh|first1=Justin St. P.|last2=Gorman|first2=Alice C.|last3=Salmond|first3=Wendy|title=Visual Displays in Space Station Culture: An Archaeological Analysis|journal=Current Anthropology|volume=62|issue=6|date=1 December 2021|issn=0011-3204|doi=10.1086/717778|pages=804–818|doi-access=free}} is being studied by analyzing many aspects, from art to dust accumulation, as well as archaeologically how material of the ISS has been discarded.{{cite web|title=Life and culture on the International Space Station|website=News|date=10 October 2021|url=https://news.flinders.edu.au/blog/2021/10/11/life-and-culture-on-the-international-space-station/|access-date=22 July 2024}}

{{See also|Space food}}

{{multiple image

| align = left

| total_width = 350

| image1 = Zvezda toilet.jpg

| caption1 = The space toilet in the Zvezda module in the Russian segment

| image2 = Node_3_toilet.jpg

| caption2 = The main toilet in the US Segment inside the Tranquility module

| caption3 =

| footer = * Both toilets are a Russian design.

}}

File:Meal STS127.jpg and STS-127 enjoy a meal inside Unity.]]

File:ISS-43 Food table in the Unity module.jpg

File:ScienceCasts- Historic Vegetable Moment on the Space Station.webm

On the USOS, most of the food aboard is vacuum sealed in plastic bags; cans are rare because they are heavy and expensive to transport. Preserved food is not highly regarded by the crew and taste is reduced in microgravity, so efforts are taken to make the food more palatable, including using more spices than in regular cooking. The crew looks forward to the arrival of any spacecraft from Earth as they bring fresh fruit and vegetables. Care is taken that foods do not create crumbs, and liquid condiments are preferred over solid to avoid contaminating station equipment. Each crew member has individual food packages and cooks them in the galley, which has two food warmers, a refrigerator (added in November 2008), and a water dispenser that provides heated and unheated water. Drinks are provided as dehydrated powder that is mixed with water before consumption. Drinks and soups are sipped from plastic bags with straws, while solid food is eaten with a knife and fork attached to a tray with magnets to prevent them from floating away. Any food that floats away, including crumbs, must be collected to prevent it from clogging the station's air filters and other equipment.

Showers on space stations were introduced in the early 1970s on Skylab and Salyut 3.{{Cite web|url=https://history.nasa.gov/SP-4208/contents.htm|title=Living and Working in Space: A History of Skylab|last1=Benson|first1=Charles Dunlap|last2=Compton|first2=William David|date=January 1983|publisher=NASA|id=SP-4208|url-status=live|archive-url=https://web.archive.org/web/20231124155632/https://history.nasa.gov/SP-4208/contents.htm|archive-date=24 November 2023}}{{rp|139}} By Salyut 6, in the early 1980s, the crew complained of the complexity of showering in space, which was a monthly activity.{{Cite tech report|url=https://history.nasa.gov/SP-4225/documentation/mhh/mirheritage.pdf|title=Mir Hardware Heritage|last=Portree|first=David S. F.|date=March 1995|publisher=NASA|page=86|oclc=755272548|id=Reference Publication 1357|url-status=live|archive-url=https://web.archive.org/web/20230810130808/https://history.nasa.gov/SP-4225/documentation/mhh/mirheritage.pdf|archive-date=10 August 2023}} The ISS does not feature a shower; instead, crewmembers wash using a water jet and wet wipes, with soap dispensed from a toothpaste tube-like container. Crews are also provided with rinseless shampoo and edible toothpaste to save water.{{Cite AV media|url=https://www.youtube.com/watch?v=uIjNfZbUYu8|archive-url=https://ghostarchive.org/varchive/youtube/20211211/uIjNfZbUYu8|archive-date=11 December 2021|url-status=live|title=Karen Nyberg Shows How You Wash Hair in Space|date=12 July 2013|last=Nyberg|first=Karen|publisher=NASA|access-date=6 June 2015|via=YouTube}}{{cbignore}}

There are two space toilets on the ISS, both of Russian design, located in Zvezda and Tranquility. These Waste and Hygiene Compartments use a fan-driven suction system similar to the Space Shuttle Waste Collection System. Astronauts first fasten themselves to the toilet seat, which is equipped with spring-loaded restraining bars to ensure a good seal. A lever operates a powerful fan and a suction hole slides open: the air stream carries the waste away. Solid waste is collected in individual bags which are stored in an aluminium container. Full containers are transferred to Progress spacecraft for disposal.{{cite web|last=Lu|first=Ed|date=8 September 2003|title=Greetings Earthling|url=http://spaceflight.nasa.gov/station/crew/exp7/luletters/lu_letter9.html|access-date=1 November 2009|publisher=NASA|archive-date=1 September 2012|archive-url=https://web.archive.org/web/20120901183936/http://spaceflight.nasa.gov/station/crew/exp7/luletters/lu_letter9.html|url-status=dead}} Liquid waste is evacuated by a hose connected to the front of the toilet, with anatomically correct "urine funnel adapters" attached to the tube so that men and women can use the same toilet. The diverted urine is collected and transferred to the Water Recovery System, where it is recycled into drinking water. In 2021, the arrival of the Nauka module also brought a third toilet to the ISS.{{Cite AV media|url=https://www.youtube.com/watch?v=fJyMw5J-GsQ|archive-url=https://ghostarchive.org/varchive/youtube/20211211/fJyMw5J-GsQ|archive-date=11 December 2021|url-status=live|title=Thomas tours the MLM module (in French with English subtitles available)|date=18 August 2021|last=Pesquet|first=Thomas|publisher=ESA|access-date=29 August 2021|via=YouTube}}{{cbignore}}

{{Main|Effect of spaceflight on the human body}}

On 12 April 2019, NASA reported medical results from the Astronaut Twin Study. Astronaut Scott Kelly spent a year in space on the ISS, while his identical twin spent the year on Earth. Several long-lasting changes were observed, including those related to alterations in DNA and cognition, when one twin was compared with the other.{{Cite news|url=https://www.nytimes.com/2019/04/11/science/scott-mark-kelly-twins-space-nasa.html|url-access=subscription|title=Scott Kelly Spent a Year in Orbit. His Body Is Not Quite the Same|last=Zimmer|first=Carl|author-link=Carl Zimmer|date=11 April 2019|access-date=12 April 2019|url-status=live|archive-url=https://web.archive.org/web/20200522170617/https://www.nytimes.com/2019/04/11/science/scott-mark-kelly-twins-space-nasa.html|archive-date=22 May 2020|quote=NASA scientists compared the astronaut to his earthbound twin, Mark. The results hint at what humans will have to endure on long journeys through space.|work=The New York Times}}{{Cite journal|title=The NASA Twins Study: A multidimensional analysis of a year-long human spaceflight|last=Garrett-Bakeman|first=Francine E.|date=12 April 2019|pages=eaau8650|bibcode=2019Sci...364.8650G|doi=10.1126/science.aau8650|display-authors=et al.|volume=364|journal=Science|pmc=7580864|issue=6436|pmid=30975860}}

In November 2019, researchers reported that astronauts experienced serious blood flow and clot problems while on board the ISS, based on a six-month study of 11 healthy astronauts. The results may influence long-term spaceflight, including a mission to the planet Mars, according to the researchers.{{Cite news|url=https://www.cnn.com/2019/11/15/health/astronaut-blood-flow-clot-scn-trnd/index.html|title=Astronauts experienced reverse blood flow and blood clots on the space station, study says|last=Strickland|first=Ashley|date=15 November 2019|access-date=16 November 2019|url-status=live|archive-url=https://web.archive.org/web/20230811175409/https://edition.cnn.com/2019/11/15/health/astronaut-blood-flow-clot-scn-trnd/index.html|archive-date=11 August 2023|publisher=CNN}}{{Cite journal|last=Marshall-Goebel|first=Karina|display-authors=et al.|date=13 November 2019|title=Assessment of Jugular Venous Blood Flow Stasis and Thrombosis During Spaceflight|journal=JAMA Network Open|volume=2|issue=11|pages=e1915011|doi=10.1001/jamanetworkopen.2019.15011|pmc=6902784|pmid=31722025}}

{{See also|Coronal mass ejection}}

File:Aurora Australis from ISS 2011 - 1.ogv, taken by the crew of Expedition 28 on an ascending pass from south of Madagascar to just north of Australia over the Indian Ocean]]

The ISS is partially protected from the space environment by Earth's magnetic field. From an average distance of about {{convert|70000|km|abbr=on}} from the Earth's surface, depending on Solar activity, the magnetosphere begins to deflect solar wind around Earth and the space station. Solar flares are still a hazard to the crew, who may receive only a few minutes warning. In 2005, during the initial "proton storm" of an X-3 class solar flare, the crew of Expedition 10 took shelter in a more heavily shielded part of the ROS designed for this purpose.{{Cite news|url=https://www.space.com/2080-solar-flare-hits-earth-mars.html|title=Solar Flare Hits Earth and Mars|last=Than|first=Ker|date=23 February 2006|url-status=live|archive-url=https://web.archive.org/web/20230811164550/https://www.space.com/2080-solar-flare-hits-earth-mars.html|archive-date=11 August 2023|work=Space.com}}{{cite web|date=10 June 2005|title=A new kind of solar storm|url=https://science.nasa.gov/science-news/science-at-nasa/2005/10jun_newstorm/|publisher=NASA|access-date=12 July 2017|archive-date=16 May 2017|archive-url=https://web.archive.org/web/20170516030602/https://science.nasa.gov/science-news/science-at-nasa/2005/10jun_newstorm/|url-status=dead}}

Subatomic charged particles, primarily protons from cosmic rays and solar wind, are normally absorbed by Earth's atmosphere. When they interact in sufficient quantity, their effect is visible to the naked eye in a phenomenon called an aurora. Outside Earth's atmosphere, ISS crews are exposed to approximately one millisievert each day (about a year's worth of natural exposure on Earth), resulting in a higher risk of cancer. Radiation can penetrate living tissue and damage the DNA and chromosomes of lymphocytes; being central to the immune system, any damage to these cells could contribute to the lower immunity experienced by astronauts. Radiation has also been linked to a higher incidence of cataracts in astronauts. Protective shielding and medications may lower the risks to an acceptable level.

Radiation levels on the ISS are between 12 and 28.8 milli rads per day,{{Cite web|url=https://www.forbes.com/sites/quora/2018/11/13/how-much-radiation-are-iss-astronauts-exposed-to/|title=How Much Radiation Are ISS Astronauts Exposed To?|last=Frost|first=Robert|date=13 November 2018|work=Forbes|access-date=4 September 2022|url-status=live|archive-url=https://web.archive.org/web/20230810131701/https://www.forbes.com/sites/quora/2018/11/13/how-much-radiation-are-iss-astronauts-exposed-to/?sh=704809db18a9|archive-date=10 August 2023}} about five times greater than those experienced by airline passengers and crew, as Earth's electromagnetic field provides almost the same level of protection against solar and other types of radiation in low Earth orbit as in the stratosphere. For example, on a 12-hour flight, an airline passenger would experience 0.1 millisieverts of radiation, or a rate of 0.2 millisieverts per day; this is one fifth the rate experienced by an astronaut in LEO. Additionally, airline passengers experience this level of radiation for a few hours of flight, while the ISS crew are exposed for their whole stay on board the station.{{cite web|title=Galactic Radiation Received in Flight|url=http://jag.cami.jccbi.gov./cariprofile.asp|url-status=dead|archive-url=https://web.archive.org/web/20100329130826/http://jag.cami.jccbi.gov/cariprofile.asp|archive-date=29 March 2010|access-date=20 May 2010|publisher=FAA Civil Aeromedical Institute}}

There is considerable evidence that psychosocial stressors are among the most important impediments to optimal crew morale and performance.{{cite book|last1=Suedfeld|first1=Peter|author1-link=Peter Suedfeld|last2=Wilk|first2=Kasia E.|last3=Cassel|first3=Lindi|contribution=Flying with Strangers: Postmission Reflections of Multinational Space Crews|title=Psychology of Space Exploration, Contemporary Research in Historical Perspective|editor-last=Vakoch|editor-first=Douglas A.|year=2011|publisher=CreateSpace Independent Publishing Platform|pages=143–176|isbn=978-1-46999770-4}} Cosmonaut Valery Ryumin wrote in his journal during a particularly difficult period on board the Salyut 6 space station: "All the conditions necessary for murder are met if you shut two men in a cabin measuring 18 feet by 20 [5.5 m × 6 m] and leave them together for two months."

NASA's interest in psychological stress caused by space travel, initially studied when their crewed missions began, was rekindled when astronauts joined cosmonauts on the Russian space station Mir. Common sources of stress in early US missions included maintaining high performance under public scrutiny and isolation from peers and family. The latter is still often a cause of stress on the ISS, such as when the mother of NASA astronaut Daniel Tani died in a car accident, and when Michael Fincke was forced to miss the birth of his second child.

A study of the longest spaceflight concluded that the first three weeks are a critical period where attention is adversely affected because of the demand to adjust to the extreme change of environment.{{Cite journal|last1=Manzey|first1=D.|last2=Lorenz|first2=B.|last3=Poljakov|first3=V.|year=1998|title=Mental performance in extreme environments: Results from a performance monitoring study during a 438-day spaceflight|journal=Ergonomics|volume=41|issue=4|pages=537–559|doi=10.1080/001401398186991|pmid=9557591}} ISS crew flights typically last about five to six months.

The ISS working environment includes further stress caused by living and working in cramped conditions with people from very different cultures who speak a different language. First-generation space stations had crews who spoke a single language; second- and third-generation stations have crew from many cultures who speak many languages. Astronauts must speak English and Russian, and knowing additional languages is even better.{{cite web|date=23 August 2004|title=Behind the Scenes: The Making of an Astronaut|url=https://spaceflight.nasa.gov/shuttle/support/training/isstraining/index.html|publisher=NASA|access-date=29 June 2018|archive-date=19 July 2016|archive-url=https://web.archive.org/web/20160719025001/http://spaceflight.nasa.gov/shuttle/support/training/isstraining/index.html|url-status=dead}}

Due to the lack of gravity, confusion often occurs. Even though there is no up and down in space, some crew members feel like they are oriented upside down. They may also have difficulty measuring distances. This can cause problems like getting lost inside the space station, pulling switches in the wrong direction or misjudging the speed of an approaching vehicle during docking.{{Cite news|url=https://www.bbc.com/future/article/20141007-why-astronauts-get-space-stupid|title=Why astronauts get the 'space stupids'|last=Robson|first=David|date=7 October 2014|publisher=BBC|url-status=live|archive-url=https://web.archive.org/web/20230811164510/https://www.bbc.com/future/article/20141007-why-astronauts-get-space-stupid|archive-date=11 August 2023}}

File:Frank De Winne on treadmill cropped.jpg, attached to the TVIS treadmill with bungee cords aboard the ISS|alt=A man running on a treadmill, smiling at the camera, with bungee cords stretching down from his waistband to the sides of the treadmill]]

The physiological effects of long-term weightlessness include muscle atrophy, deterioration of the skeleton (osteopenia), fluid redistribution, a slowing of the cardiovascular system, decreased production of red blood cells, balance disorders, and a weakening of the immune system. Lesser symptoms include loss of body mass, and puffiness of the face.

Sleep is regularly disturbed on the ISS because of mission demands, such as incoming or departing spacecraft. Sound levels in the station are unavoidably high. The atmosphere is unable to thermosiphon naturally, so fans are required at all times to process the air which would stagnate in the freefall (zero-G) environment.

To prevent some of the adverse effects on the body, the station is equipped with: two TVIS treadmills (including the COLBERT); the ARED (Advanced Resistive Exercise Device), which enables various weightlifting exercises that add muscle without raising (or compensating for) the astronauts' reduced bone density;{{Cite journal|last1=Schneider|first1=S. M.|last2=Amonette|first2=W. E.|last3=Blazine|first3=K.|last4=Bentley|first4=J.|last5=c. Lee|first5=S. M.|last6=Loehr|first6=J. A.|last7=Moore|first7=A. D.|last8=Rapley|first8=M.|last9=Mulder|first9=E. R. |last10=Smith |first10=S. M.|year=2003|title=Training with the International Space Station Interim Resistive Exercise Device|journal=Medicine & Science in Sports & Exercise|volume=35|issue=11|pages=1935–1945|doi=10.1249/01.MSS.0000093611.88198.08|pmid=14600562|doi-access=free}} and a stationary bicycle. Each astronaut spends at least two hours per day exercising on the equipment. Astronauts use bungee cords to strap themselves to the treadmill.{{cite web|date=16 June 2009|title=Bungee Cords Keep Astronauts Grounded While Running|url=http://www.nasa.gov/mission_pages/station/behindscenes/bungee_running.html|access-date=23 August 2009|publisher=NASA|archive-date=15 August 2009|archive-url=https://web.archive.org/web/20090815015910/http://www.nasa.gov/mission_pages/station/behindscenes/bungee_running.html|url-status=dead}}{{cite web|last=Kauderer|first=Amiko|date=19 August 2009|title=Do Tread on Me|url=http://www.nasa.gov/mission_pages/station/behindscenes/colbert_feature.html|access-date=23 August 2009|publisher=NASA|archive-date=21 August 2009|archive-url=https://web.archive.org/web/20090821165909/http://www.nasa.gov/mission_pages/station/behindscenes/colbert_feature.html|url-status=dead}}

{{see also|Mir#Microbiological environmental hazards|l1=Microbiological environmental hazards on the Mir space station}}

Hazardous molds that can foul air and water filters may develop aboard space stations. They can produce acids that degrade metal, glass, and rubber. They can also be harmful to the crew's health. Microbiological hazards have led to a development of the LOCAD-PTS (a portable test system) which identifies common bacteria and molds faster than standard methods of culturing, which may require a sample to be sent back to Earth.{{cite web|last=Bell|first=Trudy E.|date=11 May 2007|title=Preventing "Sick" Spaceships|url=https://science.nasa.gov/science-news/science-at-nasa/2007/11may_locad3/|access-date=29 March 2015|publisher=NASA|archive-date=14 May 2017|archive-url=https://web.archive.org/web/20170514233537/https://science.nasa.gov/science-news/science-at-nasa/2007/11may_locad3|url-status=dead}} Researchers in 2018 reported, after detecting the presence of five Enterobacter bugandensis bacterial strains on the ISS (none of which are pathogenic to humans), that microorganisms on the ISS should be carefully monitored to continue assuring a medically healthy environment for astronauts.{{Cite press release|url=https://www.biomedcentral.com/about/press-centre/science-press-releases/23-11-18|title=ISS microbes should be monitored to avoid threat to astronaut health|last=Korn|first=Anne|date=23 November 2018|publisher=BioMed Central|access-date=11 January 2019|url-status=live|archive-url=https://web.archive.org/web/20230810145840/https://www.biomedcentral.com/about/press-centre/science-press-releases/23-11-18|archive-date=10 August 2023}}{{Cite journal|last1=Singh|first1=Nitin K.|last2=Bezdan|first2=Daniela|last3=Sielaff|first3=Aleksandra Checinska|last4=Wheeler|first4=Kevin|last5=Mason|first5=Christopher E.|last6=Vendateswaran|first6=Kasthuri|display-authors=1|date=23 November 2018|title=Multi-drug resistant Enterobacter bugandensis species isolated from the International Space Station and comparative genomic analyses with human pathogenic strains|journal=BMC Microbiology|volume=18|issue=1|page=175|doi=10.1186/s12866-018-1325-2|pmc=6251167|pmid=30466389|doi-access=free|bibcode=2018BMCMb..18..175S }}

Contamination on space stations can be prevented by reduced humidity, and by using paint that contains mold-killing chemicals, as well as the use of antiseptic solutions. All materials used in the ISS are tested for resistance against fungi.{{cite web|first=Patrick L.|last=Barry|year=2000|title=Microscopic Stowaways on the ISS|url=https://science.nasa.gov/science-news/science-at-nasa/2000/ast26nov_1/|access-date=29 March 2015|archive-date=2 March 2015|archive-url=https://web.archive.org/web/20150302090949/http://science.nasa.gov/science-news/science-at-nasa/2000/ast26nov_1/|url-status=dead}} Since 2016, a series of ESA-sponsored experiments have been conducted to test the anti-bacterial properties of various materials, with the goal of developing "smart surfaces" that mitigate bacterial growth in multiple ways, using the best method for a particular circumstance. Dubbed "Microbial Aerosol Tethering on Innovative Surfaces" (MATISS), the programme involves deployment of small plaques containing an array of glass squares covered with different test coatings. They remain on the station for six months before being returned to earth for analysis.{{Cite web|url=https://www.eoportal.org/other-space-activities/iss-matiss|title=ISS: MATISS|date=30 June 2023|publisher=European Space Agency|access-date=11 June 2023|url-status=live|archive-url=https://web.archive.org/web/20230810132645/https://www.eoportal.org/other-space-activities/iss-matiss|archive-date=10 August 2023|website=eoportal.org}} The most recent and final experiment of the series was launched on 5 June 2023 aboard the SpaceX CRS-28 cargo mission to ISS, comprising four plaques. Whereas previous experiments in the series were limited to analysis by light microsocopy, this experiment uses quartz glass made of pure silica, which will allow spectrographic analysis. Two of the plaques were returned after eight months and the remaining two after 16 months.{{Cite news|url=https://arstechnica.com/science/2023/06/testing-antibacterial-surfaces-on-the-international-space-station/|title=Testing antibacterial surfaces on the International Space Station|last=Khadilkar|first=Dhananjay|date=8 June 2023|access-date=11 June 2023|url-status=live|archive-url=https://web.archive.org/web/20231108032832/https://arstechnica.com/science/2023/06/testing-antibacterial-surfaces-on-the-international-space-station/|archive-date=8 November 2023|work=Ars Technica}}

In April 2019, NASA reported that a comprehensive study had been conducted into the microorganisms and fungi present on the ISS. The experiment was performed over a period of 14 months on three different flight missions, and involved taking samples from 8 predefined locations inside the station, then returning them to earth for analysis. In prior experiments, analysis was limited to culture-based methods, thus overlooking microbes which cannot be grown in culture. The present study used molecular-based methods in addition to culturing, resulting in a more complete catalog. The results may be useful in improving the health and safety conditions for astronauts, as well as better understanding other closed-in environments on Earth such as clean rooms used by the pharmaceutical and medical industries.{{Cite press release|url=https://www.biomedcentral.com/about/press-centre/science-press-releases/08-04-19|title=NASA researchers catalogue all microbes and fungi on the International Space Station|last=Korn|first=Anne|date=7 April 2019|publisher=BioMed Central|access-date=30 August 2021|url-status=live|archive-url=https://web.archive.org/web/20230810131751/https://www.biomedcentral.com/about/press-centre/science-press-releases/08-04-19|archive-date=10 August 2023}}{{Cite journal|last=Sielaff|first=Aleksandra Checinska|display-authors=et al.|date=8 April 2019|title=Characterization of the total and viable bacterial and fungal communities associated with the International Space Station surfaces|journal=Microbiome|volume=7|issue=50|page=50|doi=10.1186/s40168-019-0666-x|pmc=6452512|pmid=30955503|doi-access=free}}

Space flight is not inherently quiet, with noise levels exceeding acoustic standards as far back as the Apollo missions.{{Cite book|last1=Limardo|first1=José G.|last2=Allen|first2=Christopher S.|last3=Danielson|first3=Richard W.|title=43rd International Conference on Environmental Systems|chapter=Assessment of Crewmember Noise Exposures on the International Space Station|date=14 July 2013|location=Vail, Colorado|publisher=American Institute of Aeronautics and Astronautics|doi=10.2514/6.2013-3516|isbn=978-1-62410-215-8}}{{Cite journal|last1=Nakashima|first1=Ann|last2=Limardo|first2=José|last3=Boone|first3=Andrew|last4=Danielson|first4=Richard W.|date=31 January 2020|title=Influence of impulse noise on noise dosimetry measurements on the International Space Station|journal=International Journal of Audiology|volume=59|issue=sup1|pages=S40–S47|doi=10.1080/14992027.2019.1698067|issn=1499-2027|pmid=31846378|s2cid=209407363|doi-access=free}} For this reason, NASA and the International Space Station international partners have developed noise control and hearing loss prevention goals as part of the health program for crew members. Specifically, these goals have been the primary focus of the ISS Multilateral Medical Operations Panel (MMOP) Acoustics Subgroup since the first days of ISS assembly and operations.{{cite web|date=May 2003|title=International Space Station Medical Operations Requirements Documents (ISS MORD), SSP 50260 Revision B|url=http://emits.sso.esa.int/emits-doc/ESTEC/AO6216-SoW-RD9.pdf|url-status=live|archive-url=https://web.archive.org/web/20200220193031/http://emits.sso.esa.int/emits-doc/ESTEC/AO6216-SoW-RD9.pdf|archive-date=20 February 2020|website=emits.sso.esa.int|publisher=NASA}}{{Cite conference|last1=Allen|first1=Christopher S.|last2=Denham|first2=Samuel A.|date=17 July 2011|title=International Space Station Acoustics – A Status Report|url=https://ntrs.nasa.gov/api/citations/20100039608/downloads/20100039608.pdf|conference=International Conference on Environmental Systems|location=Portland, Oregon|id=JSC-CN-24071 / JSC-CN-22173|archive-url=https://web.archive.org/web/20231118185324/https://ntrs.nasa.gov/api/citations/20100039608/downloads/20100039608.pdf|archive-date=18 November 2023|hdl-access=free|url-status=live|hdl=2060/20150010438|website=ntrs.nasa.gov}} The effort includes contributions from acoustical engineers, audiologists, industrial hygienists, and physicians who comprise the subgroup's membership from NASA, Roscosmos, the European Space Agency (ESA), the Japanese Aerospace Exploration Agency (JAXA), and the Canadian Space Agency (CSA).

When compared to terrestrial environments, the noise levels experienced by astronauts and cosmonauts on the ISS may seem insignificant and typically occur at levels that would not be of major concern to the Occupational Safety and Health Administration – rarely reaching 85 dBA. But crew members are exposed to these levels 24 hours a day, seven days a week, with current missions averaging six months in duration. These levels of noise also impose risks to crew health and performance in the form of sleep interference and communication, as well as reduced alarm audibility.

Over the 19 plus year history of the ISS, significant efforts have been put forth to limit and reduce noise levels on the ISS. During design and pre-flight activities, members of the Acoustic Subgroup have written acoustic limits and verification requirements, consulted to design and choose the quietest available payloads, and then conducted acoustic verification tests prior to launch.{{rp|5.7.3}} During spaceflights, the Acoustics Subgroup has assessed each ISS module's in flight sound levels, produced by a large number of vehicle and science experiment noise sources, to assure compliance with strict acoustic standards. The acoustic environment on ISS changed when additional modules were added during its construction, and as additional spacecraft arrive at the ISS. The Acoustics Subgroup has responded to this dynamic operations schedule by successfully designing and employing acoustic covers, absorptive materials, noise barriers, and vibration isolators to reduce noise levels. Moreover, when pumps, fans, and ventilation systems age and show increased noise levels, this Acoustics Subgroup has guided ISS managers to replace the older, noisier instruments with quiet fan and pump technologies, significantly reducing ambient noise levels.

NASA has adopted most-conservative damage risk criteria (based on recommendations from the National Institute for Occupational Safety and Health and the World Health Organization), in order to protect all crew members. The MMOP Acoustics Subgroup has adjusted its approach to managing noise risks in this unique environment by applying, or modifying, terrestrial approaches for hearing loss prevention to set these conservative limits. One innovative approach has been NASA's Noise Exposure Estimation Tool (NEET), in which noise exposures are calculated in a task-based approach to determine the need for hearing protection devices (HPDs). Guidance for use of HPDs, either mandatory use or recommended, is then documented in the Noise Hazard Inventory, and posted for crew reference during their missions. The Acoustics Subgroup also tracks spacecraft noise exceedances, applies engineering controls, and recommends hearing protective devices to reduce crew noise exposures. Finally, hearing thresholds are monitored on-orbit, during missions.

There have been no persistent mission-related hearing threshold shifts among US Orbital Segment crewmembers (JAXA, CSA, ESA, NASA) during what is approaching 20 years of ISS mission operations, or nearly 175,000 work hours. In 2020, the MMOP Acoustics Subgroup received the Safe-In-Sound Award for Innovation for their combined efforts to mitigate any health effects of noise.{{cite web|year=2020|title=Safe in Sound Winners|url=https://www.safeinsound.us/winners.html|url-status=live|archive-url=https://web.archive.org/web/20200625051514/https://www.safeinsound.us/winners.html|archive-date=25 June 2020|website=safeinsound.us}}

An onboard fire or a toxic gas leak are other potential hazards. Ammonia is used in the external radiators of the station and could potentially leak into the pressurised modules.{{Cite AV media|url=https://www.youtube.com/watch?v=doN4t5NKW-k|title=Departing Space Station Commander Provides Tour of Orbital Laboratory|date=3 July 2015|last=Williams|first=Suni (presenter)|publisher=NASA|time=18.00–18.17|access-date=1 September 2019|quote=And some of the things we have to worry about in space are fire ... or if we had some type of toxic atmosphere. We use ammonia for our radiators so there is a possibility that ammonia could come into the vehicle.|medium=video|archive-date=14 August 2021|archive-url=https://web.archive.org/web/20210814155134/https://www.youtube.com/watch?v=doN4t5NKW-k|url-status=live}}

{{anchor|Orbit}}

{{multiple image |align=right |total_width=400

|image1=Altitude of International Space Station.svg|caption1=Graph showing the changing altitude of the ISS from November 1998 until November 2018

|image2=Animation of International Space Station trajectory.gif |caption2=Animation of ISS orbit from 14 September 2018 to 14 November 2018. Earth is not shown.

}}

The ISS is currently maintained in a nearly circular orbit with a minimum mean altitude of {{convert|370|km|mi|-1|abbr=on}} and a maximum of {{convert|460|km|mi|-1|abbr=on}},{{Cite web|url=https://www.nasa.gov/international-space-station/space-station-overview/|title=International Space Station Overview|last=Garcia|first=Mark|date=28 April 2016|publisher=NASA|access-date=28 March 2021|url-status=live|archive-url=https://web.archive.org/web/20231120175258/https://www.nasa.gov/international-space-station/space-station-overview/|archive-date=20 November 2023}} in the centre of the thermosphere, at an inclination of 51.6 degrees to Earth's equator with an eccentricity of 0.007.{{citation needed|date=April 2024|reason=eccentricity is changing over time, heavens-above.com is reporting 0.0004733 as of 8 April 2024.}} This orbit was selected because it is the lowest inclination that can be directly reached by Russian Soyuz and Progress spacecraft launched from Baikonur Cosmodrome at 46° N latitude without overflying China or dropping spent rocket stages in inhabited areas.{{cite web|last=Cooney|first=Jim|title=Mission Control Answers Your Questions|url=http://spaceflight.nasa.gov/feedback/expert/answer/mcc/sts-112/09_04_12_54_17.html|url-status=dead|archive-url=https://web.archive.org/web/20090627185009/http://spaceflight.nasa.gov/feedback/expert/answer/mcc/sts-112/09_04_12_54_17.html|archive-date=27 June 2009|access-date=12 June 2011|quote=Jim Cooney ISS Trajectory Operations Officer|location=Houston, Texas}}{{Cite book|last=Pelt|first=Michel van|title=Into the Solar System on a String : Space Tethers and Space Elevators|publisher=Springer New York|year=2009|isbn=978-0-387-76555-6|edition=1st|location=New York, New York|page=133}} It travels at an average speed of {{convert|28000|km/h|mph|-3|abbr=}}, and completes {{Orbit|daily orbits|15.5}} orbits per day (93 minutes per orbit).{{Orbit|ref|}}{{Cite web|url=http://spaceflight.nasa.gov/realdata/tracking/index.html|title=Current ISS Tracking data|date=15 December 2008|publisher=NASA|access-date=28 January 2009|url-status=dead|archive-url=https://web.archive.org/web/20151225022741/http://spaceflight.nasa.gov/realdata/tracking/index.html|archive-date=25 December 2015}} {{PD-notice}} The station's altitude was allowed to fall around the time of each NASA shuttle flight to permit heavier loads to be transferred to the station. After the retirement of the shuttle, the nominal orbit of the space station was raised in altitude (from about 350 km to about 400 km).{{Cite news|url=https://www.nasaspaceflight.com/2011/06/europes-atv-2-depart-iss-make-way-russias-progress-m-11m/|title=Europe's ATV-2 departs ISS to make way for Russia's Progress M-11M|date=20 June 2011|access-date=1 May 2012|url-status=live|archive-url=https://web.archive.org/web/20230811170911/https://www.nasaspaceflight.com/2011/06/europes-atv-2-depart-iss-make-way-russias-progress-m-11m/|archive-date=11 August 2023|work=NASASpaceFlight.com}}{{Cite magazine|first=Rand|last=Simberg|date=29 July 2008|title=The Uncertain Future of the International Space Station: Analysis|url=http://www.popularmechanics.com/science/air_space/4275571.html|url-status=dead|magazine=Popular Mechanics|archive-url=https://web.archive.org/web/20090331140838/http://www.popularmechanics.com/science/air_space/4275571.html|archive-date=31 March 2009|access-date=6 March 2009}} Other, more frequent supply spacecraft do not require this adjustment as they are substantially higher performance vehicles.{{cite web|last=Oberg|first=James|year=2005|title=International Space Station|url=http://www.worldbookonline.com/pl/referencecenter/article?id=ar279523|access-date=3 April 2016|publisher=World Book Online Reference Center}}{{Dead link|date=October 2022 |bot=InternetArchiveBot |fix-attempted=yes }}{{cite web|title=ISS Environment|url=http://pdlprod3.hosc.msfc.nasa.gov/D-aboutiss/D6.html|archive-url=https://web.archive.org/web/20080213164432/http://pdlprod3.hosc.msfc.nasa.gov/D-aboutiss/D6.html|archive-date=13 February 2008|access-date=15 October 2007|url-status=dead|publisher=Johnson Space Center}}

Atmospheric drag reduces the altitude by about 2 km a month on average. Orbital boosting can be performed by the station's two main engines on the Zvezda service module, or Russian or European spacecraft docked to Zvezda{{'s}} aft port. The Automated Transfer Vehicle is constructed with the possibility of adding a second docking port to its aft end, allowing other craft to dock and boost the station. It takes approximately two orbits (three hours) for the boost to a higher altitude to be completed. Maintaining ISS altitude uses about 7.5 tonnes of chemical fuel per annum{{Cite magazine|url=https://www.newscientist.com/article/dn17918-rocket-company-tests-worlds-most-powerful-ion-engine/|title=Rocket company tests world's most powerful ion engine|last=Shiga|first=David|date=5 October 2009|access-date=10 August 2017|url-status=live|archive-url=https://web.archive.org/web/20230810145849/https://www.newscientist.com/article/dn17918-rocket-company-tests-worlds-most-powerful-ion-engine/|archive-date=10 August 2023|magazine=New Scientist}} at an annual cost of about $210 million.{{cite web|date=24 January 2010|title=Executive summary|url=http://www.adastrarocket.com/EXECUTIVE%20SUMMARY240110.pdf|url-status=dead|archive-url=https://web.archive.org/web/20100331171616/http://www.adastrarocket.com/EXECUTIVE%20SUMMARY240110.pdf|archive-date=31 March 2010|access-date=27 February 2010|publisher=Ad Astra Rocket Company}}

File:ISS orbits 04132013.jpg

The Russian Orbital Segment contains the Data Management System, which handles Guidance, Navigation and Control (ROS GNC) for the entire station.{{Cite web|url=https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/International_Space_Station/DMS-R_ESA_s_Data_Management_System|title=DMS-R: ESA's Data Management System|publisher=European Space Agency|url-status=live|archive-url=https://web.archive.org/web/20230811163127/https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/International_Space_Station/DMS-R_ESA_s_Data_Management_System|archive-date=11 August 2023}} Initially, Zarya, the first module of the station, controlled the station until a short time after the Russian service module Zvezda docked and was transferred control. Zvezda contains the ESA built DMS-R Data Management System.{{Cite magazine|url=https://www.esa.int/esapub/onstation/onstation17/os17_chapter6.pdf|title=Exercising Control 49 months of DMS-R Operations|last1=Reimers|first1=Claus|last2=Guyomard|first2=Daniel|date=August 2004|publisher=European Space Agency|url-status=live|archive-url=https://web.archive.org/web/20230811162355/https://www.esa.int/esapub/onstation/onstation17/os17_chapter6.pdf|archive-date=11 August 2023|magazine=on Station|volume=17}} Using two fault-tolerant computers (FTC), Zvezda computes the station's position and orbital trajectory using redundant Earth horizon sensors, Solar horizon sensors as well as Sun and star trackers. The FTCs each contain three identical processing units working in parallel and provide advanced fault-masking by majority voting.

Zvezda uses gyroscopes (reaction wheels) and thrusters to turn itself. Gyroscopes do not require propellant; instead they use electricity to 'store' momentum in flywheels by turning in the opposite direction to the station's movement. The USOS has its own computer-controlled gyroscopes to handle its extra mass. When gyroscopes 'saturate', thrusters are used to cancel out the stored momentum. In February 2005, during Expedition 10, an incorrect command was sent to the station's computer, using about 14 kilograms of propellant before the fault was noticed and fixed. When attitude control computers in the ROS and USOS fail to communicate properly, this can result in a rare 'force fight' where the ROS GNC computer must ignore the USOS counterpart, which itself has no thrusters.{{cite web|date=7 October 2003|title=Russian / US GNC Force Fight|url=http://pims.grc.nasa.gov/pimsdocs/public/ISS%20Handbook/hb_qs_vehicle_RussianUSGNCForceFight.pdf|url-status=dead|archive-url=https://web.archive.org/web/20120720193844/http://pims.grc.nasa.gov/pimsdocs/public/ISS%20Handbook/hb_qs_vehicle_RussianUSGNCForceFight.pdf|archive-date=20 July 2012|access-date=1 May 2012|website=pims.grc.nasa.gov|publisher=Glenn Research Center}}{{Cite web|url=http://spaceflight.nasa.gov/spacenews/reports/issreports/2005/iss05-7.html|title=International Space Station Status Report #05-7|date=11 February 2005|publisher=NASA|access-date=23 November 2008|url-status=dead|archive-url=https://web.archive.org/web/20050317194246/http://spaceflight.nasa.gov/spacenews/reports/issreports/2005/iss05-7.html|archive-date=17 March 2005}}{{Cite tech report|url=https://ntrs.nasa.gov/api/citations/20030038806/downloads/20030038806.pdf|title=Dynamics and Control of Attitude, Power, and Momentum for a Spacecraft Using Flywheels and Control Moment Gyroscopes|last1=Roithmayr|first1=Carlos M.|last2=Karlgaard|first2=Christopher D.|last3=Kumar|first3=Renjith R.|last4=Seywald|first4=Hans|last5=Bose|first5=David M.|date=April 2003|publisher=NASA|location=Hampton, Virginia|id=TP-2003-212178|access-date=12 July 2011|url-status=live|archive-url=https://web.archive.org/web/20230810132103/https://ntrs.nasa.gov/api/citations/20030038806/downloads/20030038806.pdf|archive-date=10 August 2023}}

Docked spacecraft can also be used to maintain station attitude, such as for troubleshooting or during the installation of the S3/S4 truss, which provides electrical power and data interfaces for the station's electronics.{{Cite news|url=https://www.nasaspaceflight.com/2007/06/atlantis-ready-to-support-iss-troubleshooting/|title=Atlantis ready to support ISS troubleshooting|last=Bergin|first=Chris|date=14 June 2007|access-date=6 March 2009|url-status=live|archive-url=https://web.archive.org/web/20100131051544/http://www.nasaspaceflight.com/2007/06/atlantis-ready-to-support-iss-troubleshooting/|archive-date=31 January 2010|work=NASASpaceFlight.com}}

{{Main|Space debris}}

The low altitudes at which the ISS orbits are also home to a variety of space debris,{{cite web|last=Hoffman|first=Michael|date=3 April 2009|title=National Space Symposium 2009: It's getting crowded up there|url=http://defensenews.com/blogs/space-symposium/2009/04/03/its-getting-crowded-up-there/#more-155|access-date=7 October 2009|publisher=Defense News}}{{dead link|date=August 2021|bot=medic}}{{cbignore|bot=medic}} including spent rocket stages, defunct satellites, explosion fragments (including materials from anti-satellite weapon tests), paint flakes, slag from solid rocket motors, and coolant released by US-A nuclear-powered satellites. These objects, in addition to natural micrometeoroids,{{Cite magazine|first=F. L.|last=Whipple|year=1949|title=The Theory of Micrometeoroids|magazine=Popular Astronomy|volume=57|page=517|bibcode=1949PA.....57..517W}} are a significant threat. Objects large enough to destroy the station can be tracked, and therefore are not as dangerous as smaller debris.{{Cite news|url=https://www.nasaspaceflight.com/2011/06/sts-135-frr-july-8-atlantis-debris-misses-iss/|title=STS-135: FRR sets 8 July Launch Date for Atlantis – Debris misses ISS|last=Bergin|first=Chris|date=28 June 2011|access-date=28 June 2011|url-status=live|archive-url=https://web.archive.org/web/20230811180427/https://www.nasaspaceflight.com/2011/06/sts-135-frr-july-8-atlantis-debris-misses-iss/|archive-date=11 August 2023|work=NASASpaceFlight.com}}{{Cite conference|url=https://ntrs.nasa.gov/api/citations/19890016664/downloads/19890016664.pdf|title=Effect of Micrometeoroid and Space Debris Impacts on the Space Station Freedom Solar Array Surfaces|last=Nahra|first=Henry|date=24–29 April 1989|publisher=NASA|location=San Diego, CA|id=TM-102287|access-date=7 October 2009|url-status=live|archive-url=https://web.archive.org/web/20231125180642/https://ntrs.nasa.gov/api/citations/19890016664/downloads/19890016664.pdf|archive-date=25 November 2023|conference=Spring Meeting of the Materials Research Society}} Objects too small to be detected by optical and radar instruments, from approximately 1 cm down to microscopic size, number in the trillions. Despite their small size, some of these objects are a threat because of their kinetic energy and direction in relation to the station. Spacewalking crew in spacesuits are also at risk of suit damage and consequent exposure to vacuum.{{cite web|title=Space Suit Punctures and Decompression|url=http://www.asi.org/adb/04/03/08/suit-punctures.html|access-date=20 July 2011|publisher=The Artemis Project|archive-date=15 June 2017|archive-url=https://web.archive.org/web/20170615061834/http://www.asi.org/adb/04/03/08/suit-punctures.html|url-status=dead}}

Ballistic panels, also called micrometeorite shielding, are incorporated into the station to protect pressurised sections and critical systems. The type and thickness of these panels depend on their predicted exposure to damage. The station's shields and structure have different designs on the ROS and the USOS. On the USOS, Whipple Shields are used. The US segment modules consist of an inner layer made from {{cvt|1.5|–|5.0|cm|in|adj=mid|-thick}} aluminium, a {{cvt|10|cm|in|adj=mid|-thick}} intermediate layers of Kevlar and Nextel (a ceramic fabric),{{Cite web|url=https://www.nasa.gov/missions/science/spinoff9_nextel_f.html|title=Superhero Ceramics!|last=Plain|first=Charlie|date=16 July 2004|publisher=NASA|url-status=dead|archive-url=https://web.archive.org/web/20080123170947/https://www.nasa.gov/missions/science/spinoff9_nextel_f.html|archive-date=23 January 2008}} and an outer layer of stainless steel, which causes objects to shatter into a cloud before hitting the hull, thereby spreading the energy of impact. On the ROS, a carbon fibre reinforced polymer honeycomb screen is spaced from the hull, an aluminium honeycomb screen is spaced from that, with a screen-vacuum thermal insulation covering, and glass cloth over the top.{{Cite web|url=http://en.roscosmos.ru/202/|title=International Space Station|publisher=Roscosmos|access-date=14 May 2020|url-status=dead|archive-url=https://web.archive.org/web/20210627235737/http://en.roscosmos.ru/202/|archive-date=27 June 2021}}

Space debris is tracked remotely from the ground, and the station crew can be notified.{{Cite web|url=http://www.orbitaldebris.jsc.nasa.gov/library/EducationPackage.pdf|title=Orbital Debris Education Package|last1=Jorgensen|first1=Kira|last2=Johnson|first2=Nicholas|publisher=NASA|access-date=1 May 2012|url-status=dead|archive-url=https://web.archive.org/web/20080408183946/http://www.orbitaldebris.jsc.nasa.gov/library/EducationPackage.pdf|archive-date=8 April 2008}} If necessary, thrusters on the Russian Orbital Segment can alter the station's orbital altitude, avoiding the debris. These Debris Avoidance Manoeuvres (DAMs) are not uncommon, taking place if computational models show the debris will approach within a certain threat distance. Ten DAMs had been performed by the end of 2009.{{Cite magazine|url=https://www.newscientist.com/article/dn16777-space-station-may-move-to-dodge-debris.html|title=Space station may move to dodge debris|last=Courtland|first=Rachel|date=16 March 2009|access-date=20 April 2010|url-status=live|archive-url=https://web.archive.org/web/20230812203203/https://www.newscientist.com/article/dn16777-space-station-may-move-to-dodge-debris/|archive-date=12 August 2023|magazine=New Scientist}}{{Cite journal|date=October 2008|title=ISS Maneuvers to Avoid Russian Fragmentation Debris|url=http://www.orbitaldebris.jsc.nasa.gov/newsletter/pdfs/ODQNv12i4.pdf|url-status=dead|journal=Orbital Debris Quarterly News|volume=12|issue=4|pages=1&2|archive-url=https://web.archive.org/web/20100527134134/http://orbitaldebris.jsc.nasa.gov/newsletter/pdfs/ODQNv12i4.pdf|archive-date=27 May 2010|access-date=20 April 2010}}{{Cite journal|date=January 2010|title=Avoiding satellite collisions in 2009|url=http://www.orbitaldebris.jsc.nasa.gov/newsletter/pdfs/ODQNv14i1.pdf|url-status=dead|journal=Orbital Debris Quarterly News|volume=14|issue=1|page=2|archive-url=https://web.archive.org/web/20100527142755/http://orbitaldebris.jsc.nasa.gov/newsletter/pdfs/ODQNv14i1.pdf|archive-date=27 May 2010|access-date=20 April 2010}} Usually, an increase in orbital velocity of the order of 1 m/s is used to raise the orbit by one or two kilometres. If necessary, the altitude can also be lowered, although such a manoeuvre wastes propellant.{{Cite press release|url=https://www.esa.int/Enabling_Support/Operations/ATV_carries_out_first_debris_avoidance_manoeuvre_for_the_ISS|title=ATV carries out first debris avoidance manoeuvre for the ISS|date=28 August 2008|publisher=European Space Agency|access-date=26 February 2010|url-status=live|archive-url=https://web.archive.org/web/20220929091613/https://www.esa.int/Enabling_Support/Operations/ATV_carries_out_first_debris_avoidance_manoeuvre_for_the_ISS|archive-date=29 September 2022}} If a threat from orbital debris is identified too late for a DAM to be safely conducted, the station crew close all the hatches aboard the station and retreat into their spacecraft in order to be able to evacuate in the event the station was seriously damaged by the debris. Partial station evacuations have occurred on 13 March 2009, 28 June 2011, 24 March 2012, 16 June 2015,{{Cite news|url=https://www.bbc.co.uk/news/science-environment-17497766|title=ISS crew take to escape capsules in space junk alert|date=24 March 2012|access-date=24 March 2012|url-status=live|archive-url=https://web.archive.org/web/20231107060517/https://www.bbc.com/news/science-environment-17497766|archive-date=7 November 2023|publisher=BBC News}} November 2021,{{Cite news|last=Tétrault-Farber|first=Gabrielle|date=3 December 2021|editor1-last=Coghill|editor1-first=Kim|title=International Space Station swerves to dodge space junk|url=https://www.reuters.com/lifestyle/science/international-space-station-swerves-dodge-space-junk-2021-12-03/|url-status=live|archive-url=https://web.archive.org/web/20230810131607/https://www.reuters.com/lifestyle/science/international-space-station-swerves-dodge-space-junk-2021-12-03/|archive-date=10 August 2023|access-date=3 December 2021|work=Reuters|editor2-last=Jones|editor2-first=Gareth}} and 27 June 2024.{{cite news|title=Russian satellite blasts debris in space, forces ISS astronauts to shelter|url=https://www.cnbc.com/2024/06/27/russian-satellite-blasts-debris-in-space-forces-iss-astronauts-to-shelter.html|access-date=27 June 2024|publisher=CNBC|date=27 June 2024}}

The November 2021 evacuation was caused by a Russian anti-satellite weapon test.{{Cite news|last1=Grush|first1=Loren|date=15 November 2021|title=Russia blows up a satellite, creating a dangerous debris cloud in space|url=https://www.theverge.com/2021/11/15/22782946/russia-asat-test-satellite-international-space-station-debris|url-status=live|archive-url=https://web.archive.org/web/20231005233548/https://www.theverge.com/2021/11/15/22782946/russia-asat-test-satellite-international-space-station-debris|archive-date=5 October 2023|work=The Verge}}{{cite news|date=16 November 2021|title=Russian Anti-Satellite Missile Test Poses No Threat – Moscow|url=https://www.bbc.com/news/science-environment-59169899|url-status=live|archive-url=https://web.archive.org/web/20211117062626/https://www.bbc.com/news/science-environment-59169899|archive-date=17 November 2021|access-date=19 November 2021|publisher=BBC News}} NASA administrator Bill Nelson said it was unthinkable that Russia would endanger the lives of everyone on ISS, including their own cosmonauts.{{cite news|last1=Atwood|first1=Kylie|last2=Sciutto|first2=Jim|last3=Fisher|first3=Kristin|last4=Gaouette|first4=Nicole|title=US says it "won't tolerate" Russia's "reckless and dangerous" anti-satellite missile test|url=https://edition.cnn.com/2021/11/15/politics/russia-anti-satellite-weapon-test-scn/index.html|url-status=live|archive-url=https://web.archive.org/web/20211119112659/https://edition.cnn.com/2021/11/15/politics/russia-anti-satellite-weapon-test-scn/index.html|archive-date=19 November 2021|access-date=20 November 2021|publisher=CNN}}

File:SDIO KEW Lexan projectile.jpg|A 7-gram object (shown in centre) shot at {{convert|7|km/s|ft/s|abbr=on}}, the orbital velocity of the ISS, made this {{convert|15|cm|in|abbr=on}} crater in a solid block of aluminium.

File:Debris-GEO1280.jpg|Radar-trackable objects, including debris, with distinct ring of geostationary satellites

File:ISS impact risk.jpg|Example of risk management: A NASA model showing areas at high risk from impact for the International Space Station

{{further|Satellite watching|Satellite flare}}

The ISS is visible in the sky to the naked eye as a visibly moving, bright white dot, when crossing the sky and being illuminated by the Sun, during twilight, the hours after sunset and before sunrise, when the station remains sunlit, outside of Earth's shadow, but the ground and sky are dark.{{Cite book|last=Price|first=Pat|title=The Backyard Stargazer: An Absolute Beginner's Guide to Skywatching With and Without a Telescope|publisher=Quarry Books|year=2005|isbn=978-1-59253-148-6|location=Gloucester, Massachusetts|page=140}} It crosses the skies at latitudes between the polar regions.{{cite web|last=Litvinov|first=Nikita|title=The season of summer visibility of the ISS has begun in Ukraine|website=Universe Space Tech|date=10 July 2024|url=https://universemagazine.com/en/do-look-up-the-season-of-summer-visibility-of-the-iss-has-begun-in-ukraine/|access-date=22 July 2024}} Depending on the path it takes across the sky, the time it takes the station to move across the horizon or from one to the other may be short or up to 10 minutes, while likely being only visible part of that time because of it moving into or out of Earth's shadow. It then returns around every 90 minutes, with the time of the day that it crosses the sky shifting over the course of some weeks, and therefore before returning to twilight and visible illumination.

Because of the size of its reflective surface area, the ISS is the brightest artificial object in the sky (excluding other satellite flares), with an approximate maximum magnitude of −4 when in sunlight and overhead (similar to Venus), and a maximum angular size of 63 arcseconds.{{Cite web|url=https://spacemath.gsfc.nasa.gov/weekly/7Page1.pdf|title=Problem 346: The International Space Station and a Sunspot: Exploring angular scales|date=19 August 2018|access-date=20 May 2022|url-status=live|archive-url=https://web.archive.org/web/20230810130645/https://spacemath.gsfc.nasa.gov/weekly/7Page1.pdf|archive-date=10 August 2023|website=Space Math @ NASA !}}

Tools are provided by a number of websites such as Heavens-Above (see Live viewing below) as well as smartphone applications that use orbital data and the observer's longitude and latitude to indicate when the ISS will be visible (weather permitting), where the station will appear to rise, the altitude above the horizon it will reach and the duration of the pass before the station disappears either by setting below the horizon or entering into Earth's shadow.{{cite web|date=2 July 2008|title=International Space Station Sighting Opportunities|url=http://spaceflight.nasa.gov/realdata/sightings/index.html|access-date=28 January 2009|publisher=NASA|archive-date=21 December 2015|archive-url=https://web.archive.org/web/20151221111201/http://spaceflight.nasa.gov/realdata/sightings/index.html|url-status=dead}}{{cite web|title=ISS – Information|url=http://www.heavens-above.com/satinfo.aspx?satid=25544&lat=0&lng=0&loc=Unspecified&alt=0&tz=CET|access-date=8 July 2010|publisher=Heavens-Above.com|archive-date=24 June 2010|archive-url=https://web.archive.org/web/20100624080244/http://www.heavens-above.com/satinfo.aspx?lat=0&lng=0&alt=0&loc=Unspecified&TZ=CET&satid=25544|url-status=live}}{{Cite journal|first=Harold F.|last=Weaver|year=1947|title=The Visibility of Stars Without Optical Aid|journal=Publications of the Astronomical Society of the Pacific|volume=59|issue=350|page=232|bibcode=1947PASP...59..232W|doi=10.1086/125956|s2cid=51963530}}{{Cite web|url=http://spaceweather.com/archive.php?view=1&day=05&month=06&year=2009|title=ISS visible during the daytime|date=5 June 2009|publisher=Spaceweather.com|access-date=5 June 2009|url-status=live|archive-url=https://web.archive.org/web/20230811172429/https://spaceweather.com/archive.php?view=1&day=05&month=06&year=2009|archive-date=11 August 2023}}

In November 2012 NASA launched its "Spot the Station" service, which sends people text and email alerts when the station is due to fly above their town.{{Cite news|date=6 November 2012|title=Get notified when the International Space Station is in your area|work=3 News NZ|url=http://www.3news.co.nz/Get-notified-when-the-International-Space-Station-is-in-your-area/tabid/1160/articleID/275612/Default.aspx|url-status=dead|access-date=21 January 2013|archive-url=https://web.archive.org/web/20131012231134/http://www.3news.co.nz/Get-notified-when-the-International-Space-Station-is-in-your-area/tabid/1160/articleID/275612/Default.aspx|archive-date=12 October 2013}} The station is visible from 95% of the inhabited land on Earth, but is not visible from extreme northern or southern latitudes.

Under specific conditions, the ISS can be observed at night on five consecutive orbits. Those conditions are 1) a mid-latitude observer location, 2) near the time of the solstice with 3) the ISS passing in the direction of the pole from the observer near midnight local time. The three photos show the first, middle and last of the five passes on 5–6 June 2014.

File:ISS 2008-01-10.jpg|Skytrack long duration exposure of the ISS

File:The ISS passing nearly overhead shortly after sunset in June 2014.jpg|The ISS on its first pass of the night passing nearly overhead shortly after sunset in June 2014

File:The ISS passing north near local midnight in June 2014.jpg|The ISS passing north on its third pass of the night near local midnight in June 2014

The ISS passing west on its 5th pass of the night before sunrise in June 2014.jpg|The ISS passing west on its fifth pass of the night before sunrise in June 2014

File:Isshtv120090917200858nm.jpg]]

Using a telescope-mounted camera to photograph the station is a popular hobby for astronomers,{{Cite web|url=https://www.hobbyspace.com/SatWatching/|title=Satellite Watching|publisher=HobbySpace|access-date=1 May 2012|url-status=live|archive-url=https://web.archive.org/web/20230811162457/https://www.hobbyspace.com/SatWatching/|archive-date=11 August 2023}} while using a mounted camera to photograph the Earth and stars is a popular hobby for crew.{{Cite web|url=https://science.nasa.gov/science-news/science-at-nasa/2003/24mar_noseprints/|title=Space StationAstrophotography – NASA Science|date=24 March 2003|publisher=NASA|access-date=1 May 2012|url-status=dead|archive-url=https://web.archive.org/web/20230811173359/https://science.nasa.gov/science-news/science-at-nasa/2003/24mar_noseprints|archive-date=11 August 2023}} The use of a telescope or binoculars allows viewing of the ISS during daylight hours.{{cite web|date=20 July 2011|title=[VIDEO] The ISS and Atlantis shuttle as seen in broad daylight|url=http://www.zmescience.com/space/video-the-iss-and-atlantis-shuttle-as-seen-in-broad-daylight/|access-date=1 May 2012|publisher=Zmescience.com|archive-date=20 August 2012|archive-url=https://web.archive.org/web/20120820023638/http://www.zmescience.com/space/video-the-iss-and-atlantis-shuttle-as-seen-in-broad-daylight/|url-status=live}}

File:Composite of 6 photos of the ISS transiting the gibbous Moon.jpg Moon]]

Transits of the ISS in front of the Sun, particularly during an eclipse (and so the Earth, Sun, Moon, and ISS are all positioned approximately in a single line) are of particular interest for amateur astronomers.{{cite web|date=22 August 2017|title=Space Station Transiting 2017 ECLIPSE, My Brain Stopped Working – Smarter Every Day 175|url=https://www.youtube.com/watch?v=lepQoU4oek4|archive-url=https://ghostarchive.org/varchive/youtube/20211211/lepQoU4oek4|archive-date=11 December 2021|url-status=live|via=YouTube}}{{cbignore}}{{Cite magazine|url=https://www.wired.com/2011/01/double-eclipse/|title=Moon and Space Station Eclipse the Sun|last=Grossman|first=Lisa|date=5 January 2011|url-status=live|archive-url=https://web.archive.org/web/20230810130728/https://www.wired.com/2011/01/double-eclipse/|archive-date=10 August 2023|magazine=WIRED}}

{{Main|Politics of the International Space Station|International Space Station programme}}

File:ISS Agreements.jpg

Involving five space programs and fifteen countries,{{Cite web|url=https://www.nasa.gov/international-space-station/space-station-international-cooperation/|title=International Cooperation|date=25 March 2015|publisher=NASA|access-date=12 April 2020|url-status=live|archive-url=https://web.archive.org/web/20231120175307/https://www.nasa.gov/international-space-station/space-station-international-cooperation/|archive-date=20 November 2023}} the International Space Station is the most politically and legally complex space exploration programme in history. The 1998 Space Station Intergovernmental Agreement sets forth the primary framework for international cooperation among the parties. A series of subsequent agreements govern other aspects of the station, ranging from jurisdictional issues to a code of conduct among visiting astronauts.{{Cite web|url=http://portal.unesco.org/shs/en/file_download.php/785db0eec4e0cdfc43e1923624154cccFarand.pdf|title=Astronauts' behaviour onboard the International Space Station: regulatory framework|last=Farand|first=André|publisher=UNESCO|url-status=dead|archive-url=https://web.archive.org/web/20060913194014/http://portal.unesco.org/shs/en/file_download.php/785db0eec4e0cdfc43e1923624154cccFarand.pdf|archive-date=13 September 2006}}

Brazil was also invited to participate in the programme, the only developing country to receive such an invitation. Under the agreement framework, Brazil was to provide six pieces of hardware, and in exchange, would receive ISS utilization rights. However, Brazil was unable to deliver any of the elements due to a lack of funding and political priority within the country. Brazil officially dropped out of the ISS programme in 2007.{{Cite journal|last=Henriques da Silva|first=Darly|date=1 February 2005|title=Brazilian participation in the International Space Station (ISS) program: commitment or bargain struck?|url=https://linkinghub.elsevier.com/retrieve/pii/S0265964604000797|journal=Space Policy|volume=21|issue=1|pages=55–63|doi=10.1016/j.spacepol.2004.11.006|bibcode=2005SpPol..21...55H|issn=0265-9646}}{{Cite journal|last1=Ansdell|first1=M.|last2=Ehrenfreund|first2=P.|last3=McKay|first3=C.|date=1 June 2011|title=Stepping stones toward global space exploration|url=https://linkinghub.elsevier.com/retrieve/pii/S0094576510004169|journal=Acta Astronautica|volume=68|issue=11|pages=2098–2113|doi=10.1016/j.actaastro.2010.10.025|bibcode=2011AcAau..68.2098A|issn=0094-5765}}

Following the 2022 Russian invasion of Ukraine, continued cooperation between Russia and other countries on the International Space Station has been put into question. Roscosmos Director General Dmitry Rogozin insinuated that Russian withdrawal could cause the International Space Station to de-orbit due to lack of reboost capabilities, writing in a series of tweets, "If you block cooperation with us, who will save the ISS from an unguided de-orbit to impact on the territory of the US or Europe? There's also the chance of impact of the 500-ton construction in India or China. Do you want to threaten them with such a prospect? The ISS doesn't fly over Russia, so all the risk is yours. Are you ready for it?"{{Cite news|url=https://arstechnica.com/science/2022/02/the-russian-invasion-of-ukraine-will-have-myriad-impacts-on-spaceflight/|title=The Russian invasion of Ukraine will have myriad impacts on spaceflight|last=Berger|first=Eric|date=25 February 2022|access-date=4 March 2022|url-status=live|archive-url=https://web.archive.org/web/20230905025847/https://arstechnica.com/science/2022/02/the-russian-invasion-of-ukraine-will-have-myriad-impacts-on-spaceflight/|archive-date=5 September 2023|work=Ars Technica}} (This latter claim is untrue: the ISS flies over all parts of the Earth between 51.6 degrees latitude north and south, approximately the latitude of Saratov.) Rogozin later tweeted that normal relations between ISS partners could only be restored once sanctions have been lifted, and indicated that Roscosmos would submit proposals to the Russian government on ending cooperation.{{Cite news|url=https://arstechnica.com/science/2022/04/no-no-no-russia-is-not-halting-cooperation-on-the-space-station/|title=Russia asked NASA to end sanctions to save the ISS, but the West didn't blink|last1=Berger|first1=Eric|date=2 April 2022|url-status=live|archive-url=https://web.archive.org/web/20230810130453/https://arstechnica.com/science/2022/04/no-no-no-russia-is-not-halting-cooperation-on-the-space-station/|archive-date=10 August 2023|work=Ars Technica}} NASA stated that, if necessary, US corporation Northrop Grumman has offered a reboost capability that would keep the ISS in orbit.{{Cite news|url=https://www.theguardian.com/science/2022/mar/01/nasa-explores-how-to-keep-international-space-station-in-orbit-without-russian-help|title=Nasa explores how to keep international space station in orbit without Russian help|date=1 March 2022|access-date=30 April 2022|url-status=live|archive-url=https://web.archive.org/web/20231005203717/https://www.theguardian.com/science/2022/mar/01/nasa-explores-how-to-keep-international-space-station-in-orbit-without-russian-help|archive-date=5 October 2023|work=The Guardian|agency=Agence France-Presse}}

On 26 July 2022, Yury Borisov, Rogozin's successor as head of Roscosmos, submitted to Russian President Putin plans for withdrawal from the programme after 2024.{{Cite news|last=Harwood|first=William|date=26 July 2022|title=Russia says it will withdraw from the International Space Station after 2024|publisher=CBS News|url=https://www.cbsnews.com/news/russia-international-space-station-exit-2024/|url-status=live|access-date=26 July 2022|archive-url=https://web.archive.org/web/20230810131755/https://www.cbsnews.com/news/russia-international-space-station-exit-2024/|archive-date=10 August 2023}} However, Robyn Gatens, the NASA official in charge of the space station, responded that NASA had not received any formal notices from Roscosmos concerning withdrawal plans.{{Cite news|last1=Roulette|first1=Joey|last2=Brunnstrom|first2=David|last3=Hunnicutt|first3=Trevor|last4=Gorman|first4=Steve|date=27 July 2022|title=Russia signals space station pullout, but NASA says it's not official yet|work=Reuters|editor1-last=Dunham|editor1-first=Will|url=https://www.reuters.com/technology/russia-has-not-signaled-space-station-withdrawal-nasa-us-official-says-2022-07-26/|url-status=live|access-date=26 July 2022|archive-url=https://web.archive.org/web/20231010212934/https://www.reuters.com/technology/russia-has-not-signaled-space-station-withdrawal-nasa-us-official-says-2022-07-26/|archive-date=10 October 2023|editor4-first=Marguerita|editor2-last=Porter|editor3-last=Oatis|editor4-last=Choy|editor3-first=Jonathan|editor2-first=Mark}}

• {{flagcountry|Canada}}
• {{flagdeco|EU}} European Space Agency
• {{flagcountry|Belgium}}
• {{flagcountry|Denmark}}
• {{flagcountry|France}}
• {{flagcountry|Germany}}
• {{flagcountry|Italy}}
• {{flagcountry|Netherlands}}
• {{flagcountry|Norway}}
• {{flagcountry|Romania}}
• {{flagcountry|Spain}}
• {{flagcountry|Sweden}}
• {{flagcountry|Switzerland}}
• {{flagcountry|United Kingdom}}
• {{flagcountry|Japan}}
• {{flagcountry|Russia}}
• {{flagcountry|United States}}

Originally the ISS was planned to be a 15-year mission.{{cite web|title=Future Plans for the International Space Station|website=NASA|date=24 July 2022|url=https://www.nasa.gov/missions/station/iss-research/ad-astra-future-plans-for-the-international-space-station/|access-date=20 July 2024}}

Therefore, an end of mission had been worked on, but was several times postponed due to the success and support for the operation of the station.{{cite web|title=The ISS was never supposed to end like this|publisher=NBC News|date=22 February 2018|url=https://www.nbcnews.com/mach/science/iss-was-never-supposed-end-ncna848771|access-date=20 July 2024}} As a result, the oldest modules of the ISS have been in orbit for more than 20 years, with their reliability having decreased. It has been proposed to use funds elsewhere instead, for example for a return to the Moon. According to the Outer Space Treaty, the parties are legally responsible for all spacecraft or modules they launch.{{Cite book|url=https://www.unoosa.org/pdf/publications/STSPACE11E.pdf|title=United Nations Treaties and Principles on Outer Space|year=2002|publisher=United Nations|location=New York|isbn=92-1-100900-6|id=ST/SPACE/11|access-date=8 October 2011|url-status=live|archive-url=https://web.archive.org/web/20231107063629/https://www.unoosa.org/pdf/publications/STSPACE11E.pdf|archive-date=7 November 2023}} An unmaintained station would pose an orbital and re-entry hazard.

Russia has stated that it plans to pull out of the ISS program after 2025. However, Russian modules will provide orbital station-keeping until 2028.{{cite web|title=What will replace the International Space Station?|website=BBC Sky at Night Magazine|date=7 December 2023|url=https://www.skyatnightmagazine.com/space-missions/replace-international-space-station|access-date=20 July 2024}}

The US planned in 2009 to deorbit the ISS in 2016. But on 30 September 2015, Boeing's contract with NASA as prime contractor for the ISS was extended to 30 September 2020. Part of Boeing's services under the contract related to extending the station's primary structural hardware past 2020 to the end of 2028.{{Cite news|url=https://www.spacedaily.com/reports/NASA_extends_Boeing_contract_for_International_Space_Station_999.html|title=NASA extends Boeing contract for International Space Station|last=Maass|first=Ryan|date=30 September 2015|access-date=2 October 2015|url-status=live|archive-url=https://web.archive.org/web/20230824213345/https://www.spacedaily.com/reports/NASA_extends_Boeing_contract_for_International_Space_Station_999.html|archive-date=24 August 2023|work=Space Daily|agency=UPI}} In July 2018, the Space Frontier Act of 2018 was intended to extend operations of the ISS to 2030. This bill was unanimously approved in the Senate, but failed to pass in the U.S. House.{{cite web|date=22 December 2018|title=Commercial space bill dies in the House|url=https://spacenews.com/commercial-space-bill-dies-in-the-house/|access-date=18 March 2019|website=SpaceNews.com}}{{cite web|last=Cruz|first=Ted|date=21 December 2018|title=S.3277 – 115th Congress (2017–2018): Space Frontier Act of 2018|url=https://www.congress.gov/bill/115th-congress/senate-bill/3277|access-date=18 March 2019|publisher=United States Congress|archive-date=9 January 2019|archive-url=https://web.archive.org/web/20190109091955/https://www.congress.gov/bill/115th-congress/senate-bill/3277|url-status=live}} In September 2018, the Leading Human Spaceflight Act was introduced with the intent to extend operations of the ISS to 2030, and was confirmed in December 2018.{{Cite tweet|number=1075840067569139712|user=SenBillNelson|title=The Senate just passed my bill to help commercial space companies launch more than one rocket a day from Florida! This is an exciting bill that will help create jobs and keep rockets roaring from the Cape. It also extends the International Space Station to 2030!|first=Bill|last=Nelson|date=20 December 2018|archive-url=https://web.archive.org/web/20200606083410/https://twitter.com/SenBillNelson/status/1075840067569139712|archive-date=6 June 2020|url-status=live}}{{cite web|date=27 September 2018|title=House joins Senate in push to extend ISS|url=https://spacenews.com/house-joins-senate-in-push-to-extend-iss/|access-date=9 May 2021|website=SpaceNews|archive-date=21 February 2023|archive-url=https://web.archive.org/web/20230221112740/https://spacenews.com/house-joins-senate-in-push-to-extend-iss/|url-status=live}}{{cite web|last=Babin|first=Brian|date=26 September 2018|title=H.R.6910 – 115th Congress (2017–2018): Leading Human Spaceflight Act|url=https://www.congress.gov/bill/115th-congress/house-bill/6910|access-date=18 March 2019|publisher=United States Congress|archive-date=12 January 2019|archive-url=https://web.archive.org/web/20190112142740/https://www.congress.gov/bill/115th-congress/house-bill/6910|url-status=live}} Congress later passed similar provisions in its CHIPS and Science Act, signed into law by U.S. President Joe Biden on 9 August 2022.{{Cite news|url=https://www.politico.com/news/2022/08/09/biden-ends-slog-on-semiconductor-bill-with-signature-00050530|title=Biden ends slog on semiconductor bill with signature|last=Johnson|first=Lamar|date=9 August 2022|access-date=24 August 2022|url-status=live|archive-url=https://web.archive.org/web/20230621192521/https://www.politico.com/news/2022/08/09/biden-ends-slog-on-semiconductor-bill-with-signature-00050530|archive-date=21 June 2023|work=Politico}}{{Cite news|url=https://www.nextgov.com/emerging-tech/2022/08/nasa-authorization-act-aims-strengthen-us-space-exploration/375394/|title=NASA Authorization Act Aims to Strengthen U.S. Space Exploration|last=Errick|first=Kirsten|date=4 August 2022|access-date=24 August 2022|url-status=live|archive-url=https://web.archive.org/web/20230810144458/https://www.nextgov.com/emerging-tech/2022/08/nasa-authorization-act-aims-strengthen-us-space-exploration/375394/|archive-date=10 August 2023|work=Nextgov.com}}

If until 2031 Commercial LEO Destinations providers are not sufficient to accommodate NASA's projects, NASA is suggesting to extend ISS operations beyond 2031.{{Cite tech report|url=https://www.nasa.gov/wp-content/uploads/2024/06/iss-deorbit-analysis-summary.pdf?emrc=669c48a232340|title=International Space Station Deorbit Analysis Summary|date=July 2024|publisher=NASA|access-date=21 July 2024}}

File:Jules Verne Automated Transfer Vehicle re-enters Earth's atmosphere.jpg, such as Jules Verne ATV.]]NASA considered originally several possible disposal options: natural orbital decay with random reentry (as with Skylab), boosting the station to a higher altitude (which would delay reentry), and a controlled de-orbit targeting a remote ocean area.{{Cite tech report|url=https://ntrs.nasa.gov/api/citations/19960053133/downloads/19960053133.pdf|title=Final Tier 2 Environmental Impact Statement for International Space Station|date=May 1996|publisher=NASA|id=TM-111720|access-date=12 July 2011|url-status=live|archive-url=https://web.archive.org/web/20230407113700/https://ntrs.nasa.gov/api/citations/19960053133/downloads/19960053133.pdf|archive-date=7 April 2023}} {{PD-notice}}

NASA determined that random reentry carried an unacceptable risk of producing hazardous space debris that could hit people or property and re-boosting the station would be costly and could also create hazards.

Prior to 2010, plans had contemplated using a slightly modified Progress spacecraft to de-orbit the ISS. However, NASA concluded Progress would not be adequate for the job, and decided on a spacecraft specifically designed for the job.{{cite web|url=https://www.planetary.org/articles/how-nasa-plans-to-deorbit-the-international-space-station|title=How NASA plans to deorbit the International Space Station|first=Jason|last=Davis|date=21 November 2023|publisher=The Planetary Society|access-date=8 June 2024}}

{{Location map | Pacific Ocean

| width = 220

| lon_deg = 142

| lon_min = 43

| lon_sec = 12

| lon_dir = W

| lat_deg = 43

| lat_min = 34

| lat_sec = 48

| lat_dir = S

| mark = Cercle rouge 100%.svg

| marksize = 20

| caption = Destination of the deorbiting ISS: the spacecraft cemetery (roughly centered on "Point Nemo", the oceanic pole of inaccessibility) in the Pacific Ocean

}}

In January 2022, NASA announced a planned date of January 2031 to de-orbit the ISS using the "U.S. Deorbit Vehicle" and direct any remnants into a remote area of the South Pacific Ocean that has come to be known as the spacecraft cemetery.{{Cite news|url=https://news.sky.com/story/nasa-plans-to-take-international-space-station-out-of-orbit-in-january-2031-by-crashing-it-into-spacecraft-cemetery-12530194|title=NASA plans to take International Space Station out of orbit in January 2031 by crashing it into 'spacecraft cemetery'|date=1 February 2022|access-date=1 February 2022|url-status=live|archive-url=https://web.archive.org/web/20231010112515/https://news.sky.com/story/nasa-plans-to-take-international-space-station-out-of-orbit-in-january-2031-by-crashing-it-into-spacecraft-cemetery-12530194|archive-date=10 October 2023|publisher=Sky News}} NASA plans to launch the deorbit vehicle in 2030, docking at the Harmony forward port.{{Cite web|last=Harwood|first=William|date=18 July 2024|title=NASA plans for space station's demise with new SpaceX 'Deorbit Vehicle'|url=https://spaceflightnow.com/2024/07/18/nasa-plans-for-space-stations-demise-with-new-spacex-deorbit-vehicle/|access-date=9 August 2024|website=Spaceflight Now}} The deorbit vehicle will remain attached, dormant, for about a year as the station's orbit naturally decays to {{cvt|220|km}}. The spacecraft would then conduct one or more orientation burns to lower the perigee to {{cvt|150|km}}, followed by a final deorbiting burn.{{Cite web|last=Foust|first=Jeff|date=9 May 2023|title=NASA proposes 'hybrid' contract approach for space station deorbit vehicle|url=https://spacenews.com/nasa-proposals-hybrid-contract-approach-for-space-station-deorbit-vehicle/|access-date=10 May 2023|website=SpaceNews}}{{Cite web|last=Casillas|first=Beverly|date=25 July 2024|title=NASA, SpaceX Share Updates on ISS Deorbit Vehicle|url=https://www.spacescout.info/2024/07/nasa-spacex-share-updates-on-iss-deorbit-vehicle/|access-date=9 August 2024|website=Space Scout}}

NASA began planning for the deorbit vehicle after becoming wary of Russia pulling out of the ISS abruptly, leaving the other partners with few good options for a controlled reentry.{{Cite web|last=Foust|first=Jeff|date=1 May 2024|title=Nelson lobbies Congress to fund ISS deorbit vehicle in supplemental spending bill|url=https://spacenews.com/nelson-lobbies-congress-to-fund-iss-deorbit-vehicle-in-supplemental-spending-bill/|access-date=3 May 2024|website=SpaceNews}} In June 2024, NASA selected SpaceX to develop the U.S. Deorbit Vehicle, a contract potentially worth $843 million. The vehicle will consist of an existing Cargo Dragon spacecraft which will be paired with a significantly lengthened trunk module which will be equipped with 46 Draco thrusters (instead of the normal 16) and will carry {{Convert|30000|kg|abbr=on}} of propellant, nearly six times the normal load. NASA is still working to secure all the necessary funding to build, launch and operate the deorbit vehicle.

On 20 February 2025, Elon Musk, CEO of SpaceX and Senior Advisor to President Trump, suggested in a tweet that the International Space Station be de-orbited "two years from now" as Musk believes the station has "served its purpose" and has "very little incremental utility". Despite this, no official decisions on moving up the de-orbiting date have been made yet by the president.{{Cite web |last=Foust |first=Jeff |date=2025-02-20 |title=Musk calls for deorbiting ISS "as soon as possible" |url=https://spacenews.com/musk-calls-for-deorbiting-iss-as-soon-as-possible/ |access-date=2025-03-01 |website=SpaceNews |language=en-US}}{{Cite web |last=Kekatos |first=Mary |title=Elon Musk calls for deorbiting of the ISS. Here's what the space station does |url=https://abcnews.go.com/US/elon-musk-calls-deorbiting-iss-space-station/story?id=119037770 |access-date=2025-03-01 |website=ABC News |language=en |publication-date=2025-02-22}}

The follow-up to NASA's program/strategy is the Commercial LEO Destinations Program, meant to allow private industry to build and maintain their own stations, and NASA procuring access as a customer, starting in 2028.{{cite web|title=How NASA plans to deorbit the International Space Station|publisher=The Planetary Society|date=21 November 2023|url=https://www.planetary.org/articles/how-nasa-plans-to-deorbit-the-international-space-station|access-date=20 July 2024}} Similarly, the ESA has been seeking new private space stations to provide orbital services, as well as retrieve materials, from the ISS.{{cite web|last=Lea|first=Robert|title=European Space Agency signs on to upcoming 'Starlab' space station|website=Space.com|date=14 November 2023|url=https://www.space.com/starlab-space-station-esa-airbus-voyager-space|access-date=20 July 2024}}{{cite news|last=Speed|first=Richard|title=ESA to fetch stuff from space before ISS takes the plunge|website=The Register|date=23 May 2024|url=https://www.theregister.com/2024/05/23/esa_iss_retrieval/|access-date=20 July 2024}} Axiom Station is planned to begin as a single module temporarily hosted at the ISS in 2027. Additionally, there have been suggestions in the commercial space industry that the ISS could be converted to commercial operations after it is retired by government entities,{{Cite news|url=https://www.theverge.com/2018/1/24/16930154/nasa-international-space-station-president-trump-budget-request-2025|title=Trump administration wants to end NASA funding for the International Space Station by 2025|last=Grush|first=Loren|date=24 January 2018|access-date=24 April 2018|url-status=live|archive-url=https://web.archive.org/web/20230810131807/https://www.theverge.com/2018/1/24/16930154/nasa-international-space-station-president-trump-budget-request-2025|archive-date=10 August 2023|work=The Verge}} including turning it into a space hotel.

Russia previously has planned to use its orbital segment for the construction of its OPSEK station after the ISS is decommissioned. The modules under consideration for removal from the current ISS included the Multipurpose Laboratory Module (Nauka; MLM), launched in July 2021, and the other new Russian modules that are proposed to be attached to Nauka. These newly launched modules would still be well within their useful lives in 2024.{{Cite news|url=http://news.bbc.co.uk/2/hi/science/nature/8064060.stm|title=Russia 'to save its ISS modules'|last=Zak|first=Anatoly|date=22 May 2009|access-date=23 May 2009|url-status=live|archive-url=https://web.archive.org/web/20230624122107/http://news.bbc.co.uk/2/hi/science/nature/8064060.stm|archive-date=24 June 2023|publisher=BBC News}} At the end of 2011, the Exploration Gateway Platform concept also proposed using leftover USOS hardware and Zvezda 2 as a refuelling depot and service station located at one of the Earth–Moon Lagrange points. However, the entire USOS was not designed for disassembly and will be discarded.{{cite web|title=DC-1 and MIM-2|url=http://www.russianspaceweb.com/iss_dc.html|url-status=dead|archive-url=https://web.archive.org/web/20090210130224/http://www.russianspaceweb.com/iss_dc.html|archive-date=10 February 2009|access-date=12 July 2011|website=RussianSpaceWeb}}

Western space industry has suggested in 2022 using the ISS as a platform to develop orbital salvage capacities, by companies such as CisLunar Industries working on using space debris as fuel,{{cite web|last=Manov|first=Elyse|title=Neumann Drive to fuel US Space Force project – SASIC|website=SASIC|date=16 May 2023|url=https://sasic.sa.gov.au/events-news-media/news/neumann-drive-to-fuel-us-space-force-project/|access-date=21 July 2024}} instead of plunging it into the ocean.{{cite web|last=O'Callaghan|first=Jonathan|title=A fiery end? How the ISS will end its life in orbit|publisher=BBC Home|date=3 May 2023|url=https://www.bbc.com/future/article/20230502-a-fiery-end-how-the-iss-will-end-its-life-in-orbit|access-date=20 July 2024}}

NASA has stated that by July 2024 it has not seen any viable proposals for reuse of the ISS or parts of it.

The ISS has been described as the most expensive single item ever constructed.{{Cite web|url=http://zidbits.com/?p=19|title=What Is The Most Expensive Object Ever Built?|date=6 November 2010|access-date=22 October 2013|url-status=dead|archive-url=https://web.archive.org/web/20210805150710/https://zidbits.com/?p=19|archive-date=5 August 2021|website=Zidbits.com}} As of 2010, the total cost was US$150 billion. This includes NASA's budget of $58.7 billion ($89.73 billion in 2021 dollars) for the station from 1985 to 2015, Russia's $12 billion, Europe's $5 billion, Japan's $5 billion, Canada's $2 billion, and the cost of 36 shuttle flights to build the station, estimated at $1.4 billion each, or $50.4 billion in total. Assuming 20,000 man-days of use from 2000 to 2015 by two- to six-person crews, each man-day would cost $7.5 million, less than half the inflation-adjusted $19.6 million ($5.5 million before inflation) per man-day of Skylab.{{Cite news|url=https://www.thespacereview.com/article/1579/1|title=Costs of US piloted programs|last=Lafleur, Claude|date=8 March 2010|access-date=18 February 2012|url-status=live|archive-url=https://web.archive.org/web/20230801132840/https://www.thespacereview.com/article/1579/1|archive-date=1 August 2023|work=The Space Review}} See author correction in comments.

The ISS has become an international symbol of human capabilities, particularly human cooperation and science,{{cite web|title=The International Space Station (ISS), humanity's shared orbital…|publisher=The Planetary Society|date=14 March 2019|url=https://www.planetary.org/space-missions/international-space-station|access-date=22 July 2024}} defining a cooperative international approach and period, instead of a looming commercialized and militarized interplanetary world.{{cite web|last=McNulty|first=Stephen|title=The International Space Station was a symbol of solidarity. Its impending doom should worry us.|website=America Magazine|date=28 July 2022|url=https://www.americamagazine.org/politics-society/2022/07/28/international-space-station-russia-withdrawal-243434|access-date=22 July 2024}}

Beside numerous documentaries such as the IMAX documentaries Space Station 3D from 2002,{{cite web|url=https://www.imdb.com/title/tt0290296/|title=Space Station 3D|publisher=IMDb|access-date=20 March 2022|archive-date=19 March 2022|archive-url=https://web.archive.org/web/20220319150635/https://www.imdb.com/title/tt0290296/|url-status=live}} or A Beautiful Planet from 2016,{{cite web|title=A Beautiful Planet – Experience Earth Like Never Before|url=http://abeautifulplanet.imax.com/|access-date=20 March 2022|work=abeautifulplanet.imax.com|archive-date=21 April 2016|archive-url=https://web.archive.org/web/20160421182448/http://abeautifulplanet.imax.com/|url-status=live}} and films like Apogee of Fear (2012){{Cite news|url=https://www.huffpost.com/entry/richard-garriott-space-movie_n_1206198|title=Richard Garriott's "Apogee of Fear," First Sci Fi Movie Ever Shot in Space, Fails To Launch|last=Wall|first=Mike|url-status=live|archive-url=https://web.archive.org/web/20230410150201/https://www.huffpost.com/entry/richard-garriott-space-movie_n_1206198|archive-date=10 April 2023|work=HuffPost}} and Yolki 5 (2016){{Cite web|url=https://ria.ru/rus_cinema/20161212/1483374933.html|title=Бекмамбетов: фильм "Елки-5" могут включить в книгу Гиннесса|trans-title=Bekmambetov: the movie 'Yolki-5' might be included in the Guinness Book of Records|date=12 December 2016|publisher=RIA Novosti|language=ru|url-status=live|archive-url=https://web.archive.org/web/20230427142206/https://ria.ru/20161212/1483374933.html|archive-date=27 April 2023}}{{Citation|title=Ёлки 5 в 720HD|url=https://www.youtube.com/watch?v=BdqByKDISFg|access-date=30 October 2023|language=ru|archive-date=30 October 2023|archive-url=https://web.archive.org/web/20231030163850/https://www.youtube.com/watch?v=BdqByKDISFg&gl=US&hl=en|url-status=live}} the ISS is the subject of feature films such as The Day After Tomorrow (2004),{{Cite book|url=https://archive.org/details/technoculturekey0000shaw|title=Technoculture: The Key Concepts|last=Shaw|first=Debra Benita|date=2008|publisher=Bloomsbury Academic|page=67|isbn=978-1-84520-298-9}} Love (2011),{{cite web|url=https://www.imdb.com/title/tt1541874/|title=Love|publisher=IMDb|access-date=20 March 2022|archive-date=20 March 2022|archive-url=https://web.archive.org/web/20220320185158/https://www.imdb.com/title/tt1541874/|url-status=live}} together with the Chinese station Tiangong 1 in Gravity (2013),{{cite web|url=https://www.imdb.com/title/tt1454468/?ref_=ttpl_pl_tt|title=Gravity|publisher=IMDb|access-date=21 March 2022|archive-date=21 March 2022|archive-url=https://web.archive.org/web/20220321195947/https://www.imdb.com/title/tt1454468/?ref_=ttpl_pl_tt|url-status=live}} Life (2017),{{Cite web|title=Life|url=https://www.sonypictures.com/movies/life|url-status=live|archive-url=https://web.archive.org/web/20230810132103/https://www.sonypictures.com/movies/life|archive-date=10 August 2023|access-date=20 March 2022|work=Sony Pictures|publisher=Sony Pictures}} and I.S.S. (2023).{{Cite magazine|last=Coggan|first=Devan|date=4 December 2023|title=Ariana DeBose is an astronaut at war in trailer for space-set thriller I.S.S.|url=https://ew.com/ariana-debose-iss-trailer-8409986|access-date=22 January 2024|magazine=Entertainment Weekly|archive-date=16 January 2024|archive-url=https://web.archive.org/web/20240116012349/https://ew.com/ariana-debose-iss-trailer-8409986|url-status=live}}

In 2022, the movie The Challenge (Doctor's House Call) was filmed aboard the ISS, and was notable for being the first feature film in which both professional actors and director worked together in space.{{Cite news|url=https://www.nytimes.com/2021/09/16/world/europe/russia-movie-space.html|url-access=subscription|title=Russia to Open New Frontier in Space, Shooting First Full-Length Movie|last1=Kramer|first1=Andrew E.|date=16 September 2021|url-status=live|archive-url=https://web.archive.org/web/20230810145219/https://www.nytimes.com/2021/09/16/world/europe/russia-movie-space.html|archive-date=10 August 2023|work=The New York Times}}

The 2023 novel by English writer Samantha Harvey, Orbital, is set in the space station. It won the 2024 Booker Prize{{cite web |date=12 November 2024 |title='Orbital' by Samantha Harvey wins 2024 Booker Prize |url=https://www.npr.org/2024/11/12/nx-s1-5184530/orbital-by-samantha-harvey-wins-2024-booker-prize |website=NPR}}{{cite web |date=15 November 2024 |title=Science Fiction Novel Wins The Booker Prize |url=https://www.starburstmagazine.com/science-fiction-novel-wins-the-booker-prize/ |website=Starburst Magazine}}

Ceridwen Dovey's Only the Astronauts, a 2024 collection of short stories in which the narrator in each story is an inanimate object in space, includes the International Space Station.{{cite web |last=Dumont |first=Adele |title=Only the Astronauts by Ceridwen Dovey review – playful and deeply moving close encounters |website=The Guardian |date=16 May 2024 |url=https://www.theguardian.com/books/article/2024/may/17/only-the-astronauts-by-ceridwen-dovey-review-playful-and-deeply-moving-close-encounters |access-date=13 March 2025}}

{{Portal|Astronomy|Aviation|Earth sciences|Spaceflight|Stars|Outer space}}

• A Beautiful Planet (2016) – IMAX documentary film showing scenes of Earth, as well as astronaut life aboard the ISS
• Center for the Advancement of Science in Space – operates the US National Laboratory on the ISS
• List of accidents and incidents involving the International Space Station
• List of commanders of the International Space Station
• List of human spaceflights to the International Space Station
• List of International Space Station expeditions
• List of International Space Station spacewalks
• List of space stations
• List of spacecraft deployed from the International Space Station
• Politics of outer space
• Science diplomacy
• Space Station 3D (2002) – Canadian documentary
• Tiangong space station – another permanently crewed station operating in Low Earth orbit

{{Notelist}}

{{Reflist}}

{{Include-NASA}}

{{NARA|url=https://nara.getarchive.net/collections/building-iss-timeline|article=Building ISS}}

• {{Cite book|url=https://www.nasa.gov/sites/default/files/atoms/files/np-2015-05-022-jsc-iss-guide-2015-update-111015-508c.pdf|title=Reference Guide to the International Space Station|date=September 2015|publisher=NASA|edition=Utilization|id=NP-2015-05-022-JSC|access-date=11 January 2018|archive-date=4 May 2021|archive-url=https://web.archive.org/web/20210504183603/https://www.nasa.gov/sites/default/files/atoms/files/np-2015-05-022-jsc-iss-guide-2015-update-111015-508c.pdf|url-status=live}}
• {{Cite book|url=https://www.nasa.gov/pdf/508318main_ISS_ref_guide_nov2010.pdf|title=Reference Guide to the International Space Station|year=2010|publisher=NASA|isbn=978-0-16-086517-6|edition=Assembly Complete|id=NP-2010-09-682-HQ|access-date=9 January 2018|archive-date=3 May 2021|archive-url=https://web.archive.org/web/20210503192448/https://www.nasa.gov/pdf/508318main_ISS_ref_guide_nov2010.pdf|url-status=live}}
• O'Sullivan, John. European Missions to the International Space Station: 2013 to 2019 (Springer Nature, 2020).
• {{cite journal|last1=Ruttley|first1=Tara M.|last2=Robinson|first2=Julie A.|last3=Gerstenmaier|first3=William H.|title=The International Space Station: Collaboration, Utilization, and Commercialization|journal=Social Science Quarterly|volume=98|issue=4|year=2017|issn=0038-4941|doi=10.1111/ssqu.12469|pages=1160–1174|url=https://www.researchgate.net/publication/322066773}}

{{Sister project links|wikt=no|n=Category:International Space Station|voy=Space}}

• {{Official website}}
• [https://www.karhukoti.com/Satellites/?search=ISS ISS Location] {{Webarchive|url=https://web.archive.org/web/20210814110202/https://www.karhukoti.com/Satellites/?search=ISS |date=14 August 2021 }}

• {{flagicon|CAN}} [http://www.asc-csa.gc.ca/eng/iss/default.asp Canadian Space Agency] {{Webarchive|url=https://web.archive.org/web/20090404061218/http://www.asc-csa.gc.ca/eng/iss/default.asp |date=4 April 2009 }}
• 20px [http://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/International_Space_Station European Space Agency] {{Webarchive|url=https://web.archive.org/web/20200513175732/http://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/International_Space_Station |date=13 May 2020 }}
• {{flagicon|FRA}} [https://iss.cnes.fr/en/internatinal-space-station Centre national d'études spatiales (National Centre for Space Studies)] {{Webarchive|url=https://web.archive.org/web/20200228205138/https://iss.cnes.fr/en/internatinal-space-station |date=28 February 2020 }}
• {{flagicon|GER}} [https://www.dlr.de/content/en/articles/missions-projects/iss/iss-international-space-station.html German Aerospace Center]. {{Webarchive|url=https://web.archive.org/web/20201107055123/https://www.dlr.de/content/en/articles/missions-projects/iss/iss-international-space-station.html |date=7 November 2020 }}.
• {{flagicon|ITA}} [https://www.asi.it/en/life-in-space/international-space-station/ Italian Space Agency] {{Webarchive|url=https://web.archive.org/web/20200809232228/https://www.asi.it/en/life-in-space/international-space-station/ |date=9 August 2020 }}
• {{flagicon|JPN}} [http://iss.jaxa.jp/en/ Japan Aerospace Exploration Agency] {{Webarchive|url=https://web.archive.org/web/20110720095815/http://iss.jaxa.jp/en/ |date=20 July 2011 }}
• {{flagicon|RUS}} [https://www.energia.ru/eng/iss/iss.html S.P. Korolev Rocket and Space Corporation Energia]. {{Webarchive|url=https://web.archive.org/web/20170627050937/http://www.energia.ru/eng/iss/iss.html |date=27 June 2017 }}.
• {{flagicon|RUS}} [http://en.roscosmos.ru/202/ Russian Federal Space Agency]. {{Webarchive|url=https://web.archive.org/web/20210627235737/http://en.roscosmos.ru/202/ |date=27 June 2021 }}.
• {{flagicon|USA}} [https://www.nasa.gov/mission_pages/station/main/index.html National Aeronautics and Space Administration] {{Webarchive|url=https://web.archive.org/web/20050907073730/http://www.nasa.gov/mission_pages/station/main/index.html |date=7 September 2005 }}

• [https://blogs.nasa.gov/spacestation/ NASA: Daily ISS Reports] {{Webarchive|url=https://web.archive.org/web/20190303120134/https://blogs.nasa.gov/spacestation/ |date=3 March 2019 }}
• [https://www.nasa.gov/mission_pages/station/research/index.html NASA: Station Science] {{Webarchive|url=https://web.archive.org/web/20180816151423/https://www.nasa.gov/mission_pages/station/research/index.html |date=16 August 2018 }}
• [http://www.esa.int/Columbus ESA: Columbus]
• [https://www.energia.ru/en/iss/researches/iss-researches.html RSC Energia: Science Research on ISS Russian Segment]. {{Webarchive|url=https://web.archive.org/web/20180111224059/https://www.energia.ru/en/iss/researches/iss-researches.html |date=11 January 2018 }}.

{{See also|List of satellite pass predictors}}

• [http://www.ustream.tv/channel/live-iss-stream Live ISS webcam] {{Webarchive|url=https://web.archive.org/web/20131019125241/http://www.ustream.tv/channel/live-iss-stream |date=19 October 2013 }} by NASA at uStream.tv
• [http://www.ustream.tv/channel/iss-hdev-payload Live HD ISS webcams] {{Webarchive|url=https://web.archive.org/web/20161229042858/http://www.ustream.tv/channel/iss-hdev-payload |date=29 December 2016 }} by NASA HDEV at uStream.tv
• [https://spotthestation.nasa.gov Sighting opportunities] {{Webarchive|url=https://web.archive.org/web/20210825234753/https://spotthestation.nasa.gov/ |date=25 August 2021 }} at NASA.gov
• [https://karhukoti.com/webtracker?s=25544 Complete Orbital Position] {{Webarchive|url=https://web.archive.org/web/20221012161445/https://karhukoti.com/webtracker?s=25544 |date=12 October 2022 }} at KarhuKoti.com
• [http://heavens-above.com/orbit.aspx?satid=25544 Real-time position] {{Webarchive|url=https://web.archive.org/web/20210827200011/http://heavens-above.com/orbit.aspx?satid=25544 |date=27 August 2021 }} at Heavens-above.com
• [https://uphere.space/satellites/25544 Real-time tracking and position] {{Webarchive|url=https://web.archive.org/web/20210817053537/https://uphere.space/satellites/25544 |date=17 August 2021 }} at uphere.space

• [https://www.flickr.com/photos/nasa2explore Johnson Space Center image gallery] {{Webarchive|url=https://web.archive.org/web/20210816021011/https://www.flickr.com/photos/nasa2explore |date=16 August 2021 }} at Flickr
• [https://www.youtube.com/watch?v=doN4t5NKW-k ISS tour with Sunita Williams] {{Webarchive|url=https://web.archive.org/web/20210814155134/https://www.youtube.com/watch?v=doN4t5NKW-k |date=14 August 2021 }} by NASA (on YouTube)
• [https://www.youtube.com/playlist?list=PLbyvawxScNbsoD_tGlw8kWCw3S5htiVKZ Journey to the ISS] {{Webarchive|url=https://web.archive.org/web/20210818023349/https://www.youtube.com/playlist?list=PLbyvawxScNbsoD_tGlw8kWCw3S5htiVKZ |date=18 August 2021 }} by ESA (on YouTube)
• [https://www.youtube.com/watch?v=vMmcLmu3V1k The Future of Hope, Kibō module documentary] {{Webarchive|url=https://web.archive.org/web/20210818123538/https://www.youtube.com/watch?v=vMmcLmu3V1k |date=18 August 2021 }} by JAXA (on YouTube)
• Seán Doran's compiled videos of orbital photography from the ISS:
• [https://www.youtube.com/watch?time_continue=1&v=7KXGZAEWzn0 Orbit – Remastered] {{Webarchive|url=https://web.archive.org/web/20210817165952/https://www.youtube.com/watch?time_continue=1&v=7KXGZAEWzn0 |date=17 August 2021 }}
• [https://www.youtube.com/watch?v=RkEV4FljRaM Orbit: Uncut] {{Webarchive|url=https://web.archive.org/web/20210818150554/https://www.youtube.com/watch?v=RkEV4FljRaM |date=18 August 2021 }}
• [https://www.youtube.com/watch?v=loOVYBSkLXQ The Four Seasons] {{Webarchive|url=https://web.archive.org/web/20210821060425/https://www.youtube.com/watch?v=loOVYBSkLXQ |date=21 August 2021 }}
• [https://www.youtube.com/watch?v=8gPzIKe92-M Nocturne – Earth at Night] {{Webarchive|url=https://web.archive.org/web/20210819060741/https://www.youtube.com/watch?v=8gPzIKe92-M |date=19 August 2021 }}
• [https://www.youtube.com/watch?v=x9vWyEPAboM Earthbound] {{Webarchive|url=https://web.archive.org/web/20210818012012/https://www.youtube.com/watch?v=x9vWyEPAboM |date=18 August 2021 }}
• [https://www.youtube.com/watch?v=3djDeb-GW3g The Pearl] {{Webarchive|url=https://web.archive.org/web/20220310081852/https://www.youtube.com/watch?v=3djDeb-GW3g |date=10 March 2022 }} (see [https://www.flickr.com/photos/seandoran/albums/72157665417217399 Flickr album] {{Webarchive|url=https://web.archive.org/web/20210815190051/https://www.flickr.com/photos/seandoran/albums/72157665417217399 |date=15 August 2021 }} for more)
• [https://www.g3xwh.com/index.php/home/iss-contact-march-2002/hlc-video-of-the-iss-contact Amateur Radio ISS Contact with Harrogate Ladies College in 2002] {{Webarchive|url=https://web.archive.org/web/20231017200406/https://g3xwh.com/index.php/home/iss-contact-march-2002/hlc-video-of-the-iss-contact |date=17 October 2023 }}

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