Lunar Gateway#Canadarm3

Formerly known as the Deep Space Gateway (DSG), the station was renamed Lunar Orbital Platform-Gateway (LOP-G) in NASA's 2018 proposal for the 2019 United States federal budget.{{cite web|title=Some snark (and details!) about NASA's proposed lunar space station|url=http://www.planetary.org/blogs/jason-davis/2018/20180226-lop-g-snark-details.html|last1=Davis|first1=Jason|publisher=The Planetary Society|access-date=February 26, 2018|archive-url=https://web.archive.org/web/20180226175759/http://www.planetary.org/blogs/jason-davis/2018/20180226-lop-g-snark-details.html|archive-date=February 26, 2018|date=February 26, 2018}}{{cite web|url=https://www.theguardian.com/science/2018/feb/12/trump-nasa-budget-moon-flying-cars-plans|title=Trump's Nasa budget: flying 'Jetson cars' and a return to the Moon|last=Yuhas|first=Alan|date=2018-02-12|newspaper=The Guardian|access-date=2018-02-25|archive-date=18 July 2019|archive-url=https://web.archive.org/web/20190718011316/https://www.theguardian.com/science/2018/feb/12/trump-nasa-budget-moon-flying-cars-plans|url-status=live}} When the NASA budget was signed into law on February 15, 2019,{{cite news |author=Foust |first=Jeff |date=February 17, 2019 |title=Final fiscal year 2019 budget bill secures $21.5 billion for NASA |url=https://spacenews.com/final-fiscal-year-2019-budget-bill-secures-21-5-billion-for-nasa/ |access-date=April 8, 2023 |publisher=Space News}} US$450 million had been committed by Congress to preliminary studies.{{cite web|url=http://www.planetary.org/blogs/casey-dreier/2019/0215-fy2019-nasa-gets-its-best-budget-in-decades.html |title=NASA just got its best budget in a decade|website=planetary.org|access-date=27 February 2019|archive-date=16 February 2019|archive-url=https://web.archive.org/web/20190216012055/http://www.planetary.org/blogs/casey-dreier/2019/0215-fy2019-nasa-gets-its-best-budget-in-decades.html|url-status=dead}}

In November 2019, NASA unveiled the name and logo of the space station inspired by the American frontier symbol of the St. Louis Gateway Arch.{{cite news |author=Pearlman |first=Robert Z. |date=September 18, 2019 |title=NASA Reveals New Gateway Logo for Artemis Lunar Orbit Way Station |url=https://www.space.com/nasa-lunar-gateway-moon-station-logo.html |url-status=live |archive-url=https://web.archive.org/web/20200628112732/https://www.space.com/nasa-lunar-gateway-moon-station-logo.html |archive-date=28 June 2020 |access-date=28 June 2020 |work=space.com}}

The Apollo Command and Service Module was the first crewed lunar orbiting spacecraft performing dockings and crew transfers with another spacecraft, the Apollo Lunar Module. Lunar bases, like the first Tranquility Base as well as concepts for lunar bases have been the main focus of human presence at the Moon.

An earlier NASA proposal for a cislunar station had been made public in 2012 and was dubbed the Deep Space Habitat. That proposal led to funding in 2015 under the NextSTEP program to study the requirements of deep space habitats.{{cite news |last1=Messier |first1=Doug |date=August 11, 2016 |title=A Closer Look at NextSTEP-2 Deep Space Habitat Concepts |url=http://www.parabolicarc.com/2016/08/11/deep-space-habitat-concepts |url-status=dead |archive-url=https://web.archive.org/web/20180916065822/http://www.parabolicarc.com/2016/08/11/deep-space-habitat-concepts/ |archive-date=16 September 2018 |access-date=19 September 2018 |publisher=Parabolic Arc}} In February 2018, it was announced that the NextSTEP studies and other ISS partner studies would help to guide the capabilities required of the Gateway's habitation modules.{{cite web|last1=Warner|first1=Cheryl|title=NASA's Lunar Outpost will Extend Human Presence in Deep Space|url=https://www.nasa.gov/feature/nasa-s-lunar-outpost-will-extend-human-presence-in-deep-space|website=nasa.gov|publisher=NASA|date=2 May 2018|access-date=19 September 2018|archive-date=25 August 2018|archive-url=https://web.archive.org/web/20180825033038/https://www.nasa.gov/feature/nasa-s-lunar-outpost-will-extend-human-presence-in-deep-space/|url-status=live}} {{PD-notice}} The solar electric Power and Propulsion Element (PPE) of the Gateway was originally a part of the now-canceled Asteroid Redirect Mission.{{Cite web |last=Foust |first=Jeff |date=2017-07-29 |title=NASA Seeks Information on Developing Deep Space Gateway Module |url=https://www.space.com/37619-nasa-deep-space-gateway-module-outreach.html |access-date=2024-05-08 |website=Space.com |language=en}}

On 7 November 2017, NASA asked the global science community to submit concepts for scientific studies that could take advantage of the Deep Space Gateway's location in cislunar space. The Deep Space Gateway Concept Science Workshop was held in Denver, Colorado, from 27 February to 1 March 2018. This three-day conference was a workshop where 196 presentations were given for possible scientific studies that could be advanced through the use of the Gateway.{{cite web|title=Deep Space 2018 Program |url=https://www.hou.usra.edu/meetings/deepspace2018/program.pdf|website=Lunar and Planetary Institute|publisher=Universities Space Research Association|access-date=27 January 2023}}

In 2018, NASA initiated the Revolutionary Aerospace Systems Concepts Academic Linkage (RASC-AL) competition for universities to develop concepts and capabilities for the Gateway. The competitors were asked to employ original engineering and analysis in one of four areas; "Gateway Uncrewed Utilization and Operations", "Gateway-Based Human Lunar Surface Access", "Gateway Logistics as a Science Platform", and "Design of a Gateway-Based Cislunar Tug". Teams of undergraduate and graduate students were asked to submit a response by 17 January 2019 addressing one of these four themes. NASA selected 20 teams to continue developing proposed concepts. Fourteen of the teams presented their projects in person in June 2019 at the RASC-AL Forum in Cocoa Beach, Florida, receiving a US$6,000 stipend to participate in the Forum. The "Lunar Exploration and Access to Polar Regions", from the University of Puerto Rico at Mayagüez, was the winning concept.{{cite web|url=https://www.nasa.gov/feature/students-blaze-new-trails-in-nasa-space-exploration-design-competition|title=Students Blaze New Trails in NASA Space Exploration Design Competition|date=21 June 2019|publisher=NASA|access-date=5 July 2019}} {{PD-notice}}

File:ISS-Derived Deep Space Habitat with CPS.jpg, consisting of a cryogenic propulsion stage, an ISS-derived habitat module, and a MPLM]]On 27 September 2017, an informal joint statement on cooperation regarding the program between NASA and Russia's Roscosmos was announced. However, in October 2020 Dmitry Rogozin, director general of Roscosmos, said that the program is too “U.S.-centric” for Roscosmos to participate,{{cite web|url=https://spacenews.com/russia-skeptical-about-participating-in-lunar-gateway/|title=Russia skeptical about participating in lunar Gateway|publisher=SPACENEWS|date=12 October 2020|access-date=25 January 2021}} and in January 2021, Roscosmos announced that it would not participate in the program.{{cite web |date=25 January 2021 |title="Роскосмос" подтвердил выход из лунного проекта Gateway |url=https://www.interfax.ru/russia/746690 |access-date=25 January 2021 |language=ru |agency=Interfax}}

As of January 2024, the Canadian Space Agency (CSA), the European Space Agency (ESA), Japan Aerospace Exploration Agency (JAXA) and Mohammed Bin Rashid Space Centre (MBRSC) plan to participate in the Gateway project, each contributing a robotic arm called Canadarm3 (CSA), refuelling and communications hardware, habitation and research capacity and an airlock module. These international elements are intended to launch after the initial NASA PPE and HALO elements are placed into lunar orbit with some co-manifested with Artemis missions.{{Cite web |last=Clark |first=Stephen |date=6 May 2020 |title=NASA plans to launch first two Gateway elements on same rocket – Spaceflight Now |url=https://spaceflightnow.com/2020/05/06/nasa-plans-to-launch-first-two-gateway-elements-on-same-rocket/ |access-date=25 January 2023 |website=Space Flight Now |language=en-US}}

File:Gateway - PPE and HALO 001.jpg]]

On 1 November 2017, NASA commissioned five studies lasting four months into affordable ways to develop the Power and Propulsion Element (PPE), leveraging private companies' plans. These studies had a combined budget of US$2.4 million. The companies performing the PPE studies were Boeing, Lockheed Martin, Orbital ATK, Sierra Nevada and Space Systems/Loral.{{cite web |last1=Russell |first1=Jimi |date=November 2017 |title=NASA Selects Studies for Gateway Power and Propulsion Element |url=https://www.nasa.gov/press-release/nasa-selects-studies-for-gateway-power-and-propulsion-element |url-status=live |archive-url=https://web.archive.org/web/20180112203046/https://www.nasa.gov/press-release/nasa-selects-studies-for-gateway-power-and-propulsion-element/ |archive-date=12 January 2018 |access-date=2 November 2017 |website=nasa.gov |publisher=NASA}} {{PD-notice}} These awards are in addition to the ongoing set of NextSTEP-2 awards made in 2016 to study development and make ground prototypes of habitat modules that could be used on the Gateway as well as other commercial applications, so the Gateway is likely to incorporate components developed under NextSTEP as well.{{cite web |last1=Mahoney |first1=Erin |date=9 August 2016 |title=NextSTEP Partners Develop Ground Prototypes to Expand our Knowledge of Deep Space Habitats |url=https://www.nasa.gov/feature/nextstep-partnerships-develop-ground-prototypes |url-status=live |archive-url=https://web.archive.org/web/20170410051227/https://www.nasa.gov/feature/nextstep-partnerships-develop-ground-prototypes/ |archive-date=10 April 2017 |access-date=6 November 2017 |website=nasa.gov |publisher=NASA}} {{PD-notice}} The PPE will use four 6 kW BHT-6000 Busek Hall-effect thrusters{{Cite press release|title=Maxar and Busek Thruster System for NASA Lunar Gateway Passes Critical Milestone|url=https://www.prnewswire.com/news-releases/maxar-and-busek-thruster-system-for-nasa-lunar-gateway-passes-critical-milestone-301250199.html|access-date=2021-04-28|website=www.prnewswire.com|language=en}} and three 12 kW NASA/Aerojet Rocketdyne Advanced Electric Propulsion System (AEPS) Hall-effect thrusters for a total engine output fractionally under 50 kW.{{Cite web|url=https://newatlas.com/space/advanced-electric-propulsion-system-aeps-full-power-test/|title=Advanced Electric Propulsion System passes full-power test milestone|date=15 November 2019|website=New Atlas}} In 2019, the contract to manufacture the PPE was awarded to Maxar Technologies.{{cite press release|url=https://www.nasa.gov/press-release/nasa-awards-artemis-contract-for-lunar-gateway-power-propulsion|title=NASA Awards Artemis Contract for Lunar Gateway Power, Propulsion|publisher=NASA|date=23 May 2019|access-date=11 December 2019|archive-date=20 September 2019|archive-url=https://web.archive.org/web/20190920171731/https://www.nasa.gov/press-release/nasa-awards-artemis-contract-for-lunar-gateway-power-propulsion/|url-status=live}} {{PD-notice}} After a one-year demonstration period, NASA intended to "exercise a contract option to take over control of the spacecraft".{{Cite web |last=Sloss |first=Philip |date=2018-09-11 |title=NASA updates Lunar Gateway plans |url=https://www.nasaspaceflight.com/2018/09/nasa-lunar-gateway-plans/ |access-date=2024-05-08 |website=NASASpaceFlight.com |language=en-US}} Its expected service time is about 15 years.Jason Crusan. [https://www.nasa.gov/sites/default/files/atoms/files/20181206-crusan-gateway-reduced-v4.pdf Gateway Update] {{Webarchive|url=https://web.archive.org/web/20200803144944/https://www.nasa.gov/sites/default/files/atoms/files/20181206-crusan-gateway-reduced-v4.pdf|date=3 August 2020}} NASA Advisory Council, Human Exploration and Operations Committee, 7 December 2018 {{PD-notice}} In late 2023, it was reported that flight qualification testing was occurring on the thrusters for the Power and Propulsion Element.{{Cite web |title=True Blue: High-Power Propulsion for Gateway – NASA |url=https://www.nasa.gov/image-article/true-blue-high-power-propulsion-for-gateway/ |access-date=2024-03-31 |language=en-US}}

The Gateway will be deployed in a near-rectilinear halo orbit (NRHO) around the Moon.{{cite book |chapter-url=https://s3-us-west-2.amazonaws.com/advspace.publicshare/NRHO+OD+with+Simulated+DSN.pdf |quote=The current nominal orbit for the Gateway is a 9:2 synodic resonant southern L2 NRHO |chapter=Near Rectilinear Halo Orbit Determination with Simulated DSN Observations |first=Nathan |last=Parrish |title=AIAA Scitech 2020 Forum |display-authors=etal |date=5 Jan 2020 |publisher=American Institute of Aeronautics and Astronautics |doi=10.2514/6.2020-1700|isbn=978-1-62410-595-1 }} The eccentricity of the chosen NRHO takes the station within {{cvt|1500|km}} of the lunar north pole surface at closest approach, and as far away as {{cvt|70000|km}} over the lunar south pole, with a period of about 7 days.[https://phys.org/news/2019-07-angelic-halo-orbit-chosen-humankind.html Angelic halo orbit chosen for humankind's first lunar outpost.] {{Webarchive|url=https://web.archive.org/web/20190811175615/https://phys.org/news/2019-07-angelic-halo-orbit-chosen-humankind.html|date=11 August 2019}} European Space Agency, Published by PhysOrg, 19 July 2019{{Cite web |last=Szondy |first=David |date=2019-07-19 |title=Halo orbit selected for Gateway space station |url=https://newatlas.com/orbit-halo-gateway/60657/ |access-date=2024-05-08 |website=New Atlas |language=en-US}}{{cite news |url=https://spacenews.com/nasa-cubesat-to-test-lunar-gateway-orbit/|title=NASA cubesat to test lunar Gateway orbit|last=Foust|first=Jeff|publisher=SpaceNews|date=16 September 2019|access-date=15 June 2020}} One of the advantages of an NRHO is the minimal amount of communications blackout with the Earth.

Traveling to and from cislunar space (lunar orbit) is intended to develop the knowledge and experience necessary to venture beyond the Moon and into deep space. The proposed NRHO would allow lunar expeditions from the Gateway to reach a low polar orbit with a Δv of 730 m/s and a half a day of transit time. Orbital station-keeping would require less than 10 m/s of Δv per year, and the orbital inclination could be shifted with a relatively small Δv expenditure, allowing access to most of the lunar surface. Spacecraft launched from Earth would perform a powered flyby of the Moon {{nowrap|(Δv ≈ 180 m/s)}} followed by a {{nowrap|Δv ≈ 240 m/s}} NRHO insertion burn to dock with the Gateway as it approaches the apoapsis point of its orbit. The total travel time would be 5 days; the return to Earth would be similar in terms of trip duration and Δv requirement if the spacecraft spends 11 days at the Gateway. The crewed mission duration of 21 days and {{nowrap|Δv ≈ 840 m/s}} is limited by the capabilities of the Orion life support and propulsion systems.{{cite web|last1=Whitley|first1=Ryan|last2=Martinez|first2=Roland|title=Options for Staging Orbits in Cis-Lunar Space |url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20150019648.pdf|website=nasa.gov|publisher=NASA|date=21 October 2015|access-date=19 September 2018|archive-date=30 July 2019|archive-url=https://web.archive.org/web/20190730111818/https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20150019648.pdf|url-status=live}} {{PD-notice}}

Gateway will be the first modular space station to be both human-rated, and autonomously operating most of the time in its early years, as well as being the first deep-space station, far from low Earth orbit. This will be enabled by more sophisticated executive control software than on any prior space station, which will monitor and control all systems. The high-level architecture is provided by the Robotics and Intelligence for Human Spaceflight lab at NASA and implemented at NASA facilities. The Gateway could conceivably also support in-situ resource utilization (ISRU) development and testing from lunar and asteroid sources,[https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20180002054.pdf NASA.gov] {{Webarchive |url=https://web.archive.org/web/20180731035911/https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20180002054.pdf|date=31 July 2018}} Research Possibilities Beyond Deep Space Gateway] David Smitherman, Debra Needham, Ruthan Lewis, NASA, February 28, 2018 {{PD-notice}} and would offer the opportunity for a gradual buildup of capabilities for more complex missions over time.[https://www.nasa.gov/sites/default/files/atoms/files/march_2017_nac_charts_architecturejmf_rev_3_tagged.pdf NASA.gov] {{Webarchive |url=https://web.archive.org/web/20200102091140/https://www.nasa.gov/sites/default/files/atoms/files/march_2017_nac_charts_architecturejmf_rev_3_tagged.pdf|date=2 January 2020}} Human Exploration and Operations Mission Directorate - Architecture Status], Jim Free, NASA, 28 March 2017 {{PD-notice}}

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File:Near Rectilinear Halo Orbit (NRHO).png|Near-rectilinear halo orbit (NRHO) in cislunar space, as illustrated by an A.I. Solutions, Inc. using the FreeFlyer software

File:Lunar Gateway Orbit 7days Earth-Moon fixed.png|Lunar Gateway orbit – trajectory plot over seven days with the view fixed on Moon and Earth

File:Lunar Gateway orbit animation.webm|Lunar Gateway orbit animation – view fixed on Moon and Earth

File:Lunar Gateway orbit animation moon north.webm|Lunar Gateway orbit animation – view from above the lunar north pole with Earth fixed below the frame bottom

File:Lunar Gateway rendering 2.webp

File:LOP-G interior with Astronauts.jpg, Shannon Walker, Raja Chari, and Stephanie Wilson inside of the Gateway mock-up module at the Space Station Processing Facility in the Kennedy Space Center, Florida]]

File:LOP-G_module_training_mock-up_module_group_photo.jpg]]

For supporting the first crewed mission to the station (Artemis IV) planned for 2028, the Gateway will begin as a minimal space station composed of only two modules: the Power and Propulsion Element (PPE) and the Habitation and Logistics Outpost (HALO). Both PPE and HALO will be assembled on Earth and launched together on a Falcon Heavy rocket in 2027.{{cite web|url=https://www.nasa.gov/reference/gateway-about/ |title=NASA, Gateway Overview |work=NASA |date=3 May 2024|access-date=8 May 2024}} They are expected to reach lunar orbit after nine to ten months.{{cite web|last1=Foust|first1=Jeff|title=NASA refines plans for launching Gateway and other Artemis elements|url=https://spacenews.com/nasa-refines-plans-for-launching-gateway-and-other-artemis-elements/|website=spacenews.com|publisher=SpaceNews|access-date=18 May 2020|date=14 May 2020|archive-date=16 May 2020|archive-url=https://archive.today/20200516065402/https://spacenews.com/nasa-refines-plans-for-launching-gateway-and-other-artemis-elements/|url-status=live}} The I-Hab module, a contribution from ESA and JAXA, is to be launched on the SLS Block 1B as a co-manifested payload on the Artemis IV crewed Orion mission.{{cite web|url=https://www.nasa.gov/sites/default/files/atoms/files/fy2022_congressional_justification_nasa_budget_request.pdf|quote= Delivery of I-Hab to the Gateway will be via the SLS Block 1B launch vehicle with Orion providing orbital insertion and docking. |page=PDF page 97, in-text page DEXP-67 |title=NASA FY 2022 Budget Estimates}} All modules will be connected using the International Docking System Standard.{{Cite web |last=Patel |first=Neel V. |date=2017-04-04 |title=NASA Unveils Deep Space Gateway and Transport Architectures |url=https://www.inverse.com/article/29948-nasa-deep-space-gateway-transport-architectures-mars-travel |access-date=2024-05-08 |website=Inverse |language=en}}

• {{Anchor|PPE|Power and Propulsion Element}} The Power and Propulsion Element (PPE) started development at the Jet Propulsion Laboratory during the now canceled Asteroid Redirect Mission (ARM). The original concept was a robotic, high-performance solar electric spacecraft that would retrieve a multi-ton boulder from an asteroid and bring it to lunar orbit for study.{{cite web |url=http://www.nasa.gov/feature/jpl/jpl-seeks-robotic-spacecraft-development-for-asteroid-redirect-mission|title=JPL Seeks Robotic Spacecraft Development for Asteroid Redirect Mission|last=Greicius|first=Tony |date=2016-09-20|publisher=NASA|access-date=30 May 2019|archive-date=17 June 2019|archive-url=https://web.archive.org/web/20190617075954/https://www.nasa.gov/feature/jpl/jpl-seeks-robotic-spacecraft-development-for-asteroid-redirect-mission/|url-status=live}} {{PD-notice}} When ARM was canceled, the solar electric propulsion was repurposed for the Gateway.{{cite web |url=https://spacenews.com/nasa-closing-out-asteroid-redirect-mission/|title=NASA closing out Asteroid Redirect Mission|date=2017-06-14|publisher=SpaceNews|access-date=30 May 2019}}{{cite web |url=https://www.jpl.nasa.gov/missions/asteroid-redirect-robotic-mission-arrm/|title=Asteroid Redirect Robotic Mission|website=jpl.nasa.gov|publisher=NASA|access-date=30 May 2019|archive-date=30 May 2019 |archive-url=https://web.archive.org/web/20190530113407/https://www.jpl.nasa.gov/missions/asteroid-redirect-robotic-mission-arrm/|url-status=live}} {{PD-notice}} The PPE will allow access to the entire lunar surface and act as a space tug for visiting craft. It will also serve as the command and communications center of the Gateway.{{cite web|url=http://www.sci-news.com/space/deep-space-gateway-transport-mars-moon-exploration-04756.html|title=Deep Space Gateway and Transport: Concepts for Mars, Moon Exploration Unveiled|date=4 April 2017 |publisher=Science News|access-date=2019-05-30|archive-date=30 May 2019|archive-url=https://web.archive.org/web/20190530113409/http://www.sci-news.com/space/deep-space-gateway-transport-mars-moon-exploration-04756.html|url-status=live}}{{cite web |url=https://spaceflightnow.com/2019/05/24/nasa-chooses-maxar-to-build-keystone-module-for-lunar-gateway-station/|title=NASA chooses Maxar to build keystone module for lunar Gateway station|last=Clark |first=Stephen|publisher=Spaceflight Now|access-date=2019-05-30|archive-date=5 June 2019|archive-url=https://web.archive.org/web/20190605140715/https://spaceflightnow.com/2019/05/24/nasa-chooses-maxar-to-build-keystone-module-for-lunar-gateway-station/|url-status=live}} The PPE is intended to have a launch mass of {{cvt|5000|kg}} with propellant accounting for half that mass{{cite web|last=Boyle|first=Alan| url=https://www.geekwire.com/2019/nasa-says-maxar-will-build-first-big-piece-gateway-space-outpost-lunar-orbit/|title=NASA says Maxar will build the first big piece for Gateway station in lunar orbit|publisher=GeekWire|date=23 May 2019|access-date=28 August 2023}} and the capability to generate 50 kW{{cite web|last=Foust|first=Jeff |url=https://spacenews.com/nasa-issues-study-contracts-for-deep-space-gateway-element/|title=NASA issues study contracts for Deep Space Gateway element|publisher=SpaceNews|date=3 November 2017|access-date=11 December 2019}} of solar electric power for its ion thrusters, which can be supplemented by chemical propulsion.{{cite web |last1=Gebhardt |first1=Chris |date=6 April 2017 |title=NASA finally sets goals, missions for SLS – eyes multi-step plan to Mars |url=https://www.nasaspaceflight.com/2017/04/nasa-goals-missions-sls-eyes-multi-step-mars |url-status=live |archive-url=https://web.archive.org/web/20170821221210/https://www.nasaspaceflight.com/2017/04/nasa-goals-missions-sls-eyes-multi-step-mars/ |archive-date=21 August 2017 |access-date=April 9, 2017 |publisher=NASASpaceFlight.com}} In May 2019, Maxar Technologies was contracted by NASA to manufacture this module, which will also supply the station with electrical power and is based on Maxar's 1300 series satellite bus. The PPE will use Busek 6 kW Hall-effect thrusters and NASA Advanced Electric Propulsion System (AEPS) Hall-effect thrusters.{{cite news|last=Foust|first=Jeff|title=NASA selects Maxar to build first Gateway element|url=https://spacenews.com/nasa-selects-maxar-to-build-first-gateway-element|access-date=May 23, 2019|publisher=SpaceNews|date=May 23, 2019}}R. Joseph Cassady, Sam Wiley, Jerry Jackson. [https://www.researchgate.net/profile/R_Cassady/publication/328997773_Status_of_Advanced_Electric_Propulsion_Systems_for_Exploration_Missions/links/5beee33692851c6b27c37074/Status-of-Advanced-Electric-Propulsion-Systems-for-Exploration-Missions.pdf Status of Advanced Electric Propulsion Systems for Exploration Missions.] {{Webarchive|url=https://web.archive.org/web/20190613101313/https://www.researchgate.net/profile/R_Cassady/publication/328997773_Status_of_Advanced_Electric_Propulsion_Systems_for_Exploration_Missions/links/5beee33692851c6b27c37074/Status-of-Advanced-Electric-Propulsion-Systems-for-Exploration-Missions.pdf|date=13 June 2019}}. Aerojet Rocketdyne, October 2018. Maxar was awarded a firm-fixed-price contract of US$375 million to build the PPE. NASA is supplying the PPE with an S-band communications system to provide a radio link with nearby vehicles and a passive docking adapter to receive the Gateway's future utilization module.{{cite news|last=Clark|first=Stephen|title=NASA chooses Maxar to build keystone module for lunar Gateway station |url=https://spaceflightnow.com/2019/05/24/nasa-chooses-maxar-to-build-keystone-module-for-lunar-gateway-station|publisher=Spaceflight Now|date=May 24, 2019|access-date=13 July 2019|archive-date=5 June 2019 |archive-url=https://web.archive.org/web/20190605140715/https://spaceflightnow.com/2019/05/24/nasa-chooses-maxar-to-build-keystone-module-for-lunar-gateway-station/|url-status=live}} NASA awarded a contract of US$331.8 million to launch PPE on a SpaceX Falcon Heavy in 2027 with the HALO module.{{cite web |url=https://www.nasa.gov/press-release/nasa-awards-contract-to-launch-initial-elements-for-lunar-outpost |title=NASA Awards Contract to Launch Initial Elements for Lunar Outpost |work=NASA |date=9 February 2021 |access-date=9 February 2021}}

• {{Anchor|HALO|Habitation and Logistics Outpost}} The Habitation and Logistics Outpost (HALO),{{cite web|last=Foust|first=Jeff|url=https://spacenews.com/iss-partners-endorse-modified-gateway-plans/|title=ISS partners endorse modified Gateway plans|publisher=SpaceNews|date=30 August 2019|access-date=11 December 2019}}{{Cite press release |title=NASA Asks American Companies to Deliver Supplies for Artemis Moon Missions |date=23 August 2019 |publisher=NASA |url=https://www.nasa.gov/news-release/nasa-asks-american-companies-to-deliver-supplies-for-artemis-moon-missions/ |last=Sempsrott |first=Danielle |access-date=30 August 2019 |id=M019-14}} {{PD-notice}} also called the Minimal Habitation Module (MHM) and formerly known as the Utilization Module,{{cite web |author1= |title=Humans in Deep Space |url=http://www.planetary.org/explore/space-topics/space-missions/humans-in-deep-space.html |url-status=live |archive-url=https://web.archive.org/web/20191117234651/https://www.planetary.org/explore/space-topics/space-missions/humans-in-deep-space.html |archive-date=17 November 2019 |access-date=6 August 2019 |website=The Planetary Society}} will be built by Northrop Grumman Innovation Systems (NGIS).{{cite web|last=Foust|first=Jeff|url=https://spacenews.com/nasa-to-sole-source-gateway-habitation-module-to-northrop-grumman/|title=NASA to sole source Gateway habitation module to Northrop Grumman|publisher=SpaceNews|date=23 July 2019|access-date=11 December 2019}}{{cite web|title=Justification for other than full and open competition (JOFOC) for the Minimal Habitation Module (MHM)|url=https://www.fbo.gov/index.php?tab=documents&tabmode=form&subtab=core&tabid=d4e9e11d78e9dd0b8bd05395b3d82c7f|publisher=Federal Business Opportunities|access-date=23 July 2019|ref=Solicitation 80JSC019GTWYHAB|archive-date=3 September 2019|archive-url=https://web.archive.org/web/20190903173343/https://www.fbo.gov/index.php?tab=documents&tabmode=form&subtab=core&tabid=d4e9e11d78e9dd0b8bd05395b3d82c7f|url-status=live}} {{PD-notice}} A single Falcon Heavy will launch HALO in 2027 along with the PPE module. The HALO is based directly on a Cygnus Cargo resupply module{{cite web|last1=Gebhardt|first1=Chris|title=Northrop Grumman outlines HALO plans for Gateway's central module|date=7 August 2020|url=https://www.nasaspaceflight.com/2020/08/northrop-halo-plans-gateway/|publisher=NASASpaceFlight.com|access-date=13 August 2020|archive-date=10 August 2020|archive-url=https://web.archive.org/web/20200810151335/https://www.nasaspaceflight.com/2020/08/northrop-halo-plans-gateway/|url-status=live}} to the outside of which radial docking ports, body mounted radiators (BMRs), batteries and communications antennae will be added. The HALO will be a scaled-down habitation module,{{cite web|last=Messier|first=Doug|url=http://www.parabolicarc.com/2019/07/23/nasa-awards-contract-to-northrop-grumman-for-lunar-gateway-habitat-module/|title=NASA Awards Contract to Northrop Grumman for Gateway Habitat Module|publisher=Parabolic Arc|date=23 July 2019|access-date=11 December 2019|archive-date=29 July 2019|archive-url=https://web.archive.org/web/20190729005145/http://www.parabolicarc.com/2019/07/23/nasa-awards-contract-to-northrop-grumman-for-lunar-gateway-habitat-module/|url-status=dead}} yet it will feature a functional pressurized volume providing sufficient command, control and data handling capabilities, energy storage and power distribution, thermal control, communications and tracking capabilities, two axial and up to two radial docking ports, stowage volume, environmental control and life support systems to augment the Orion spacecraft and support a crew of four for at least 30 days. The overall HALO mass is expected to be 8–9 tons depending on the final internal layout configuration and launch vehicle lift capability.{{Cite web |last=Evans |first=Ben |date=2021-07-10 |title=NASA, Northrop Grumman Finalize Lunar Gateway Integration Contract|url=https://www.americaspace.com/2021/07/10/nasa-northrop-grumman-finalize-lunar-gateway-integration-contract/ |access-date=2023-08-11 |website=AmericaSpace |language=en-US}} On 5 June 2020, Northrop Grumman Innovation Systems was awarded a contract, by NASA, of US$187 million to complete the preliminary design of HALO.{{cite web|url=https://spaceflightnow.com/2020/06/09/nasa-signs-gateway-habitat-design-contract-with-northrop-grumman/|title=NASA signs Gateway habitat design contract with Northrop Grumman|publisher=Spaceflight Now|date=9 June 2020|access-date=10 June 2020|archive-date=10 June 2020|archive-url=https://web.archive.org/web/20200610222822/https://spaceflightnow.com/2020/06/09/nasa-signs-gateway-habitat-design-contract-with-northrop-grumman/|url-status=live}} On 9 July 2021, NASA signed a separate contract with Northrop for the fabrication of HALO, and for integration with the PPE being built by Maxar, for US$935 million. In July 2022, Northrop Grumman awarded Solstar a contract to supply Wi-Fi access for personnel and equipment in the HALO module.{{Cite web |last=Werner |first=Debra |date=2022-07-18 |title=Northrop Grumman taps Solstar for HALO Module Wi-Fi |url=https://spacenews.com/solstar-halo-wi-fi/ |access-date=2023-01-13 |website=SpaceNews |language=en-US}}{{Cite web |title=NM firm builds Wi-Fi 'hotspot' for NASA moon station |url=https://news.yahoo.com/nm-firm-builds-wi-fi-035900403.html |access-date=2023-01-13 |website=news.yahoo.com |date=3 August 2022 |language=en-US}} On 2 April 2024, it was announced that welding was complete on the module and that the next step was for the module to undergo a series of stress tests upon successful completion of which it would be transported to Northrop Grumman's facility in Arizona for final outfitting.{{Cite web |last=Connell |first=Dylan |date=2024-04-02 |title=A Home for Astronauts around the Moon |url=https://www.nasa.gov/image-article/a-home-for-astronauts-around-the-moon/ |access-date=2024-04-03 |website=NASA}}

• {{Anchor|ESPRIT}} File:Team Gateway see you at the moon LR.jpg, France]] The European System Providing Refueling, Infrastructure and Telecommunications (ESPRIT) service module will provide additional xenon and hydrazine capacity, additional communications equipment, and an airlock for science packages.{{cite web|url=https://www.nasaspaceflight.com/2018/09/nasa-lunar-gateway-plans/|title=NASA updates lunar Gateway plans|date=September 11, 2018|first=Philip|last=Sloss|publisher=NASASpaceFlight.com|access-date=15 September 2018|archive-date=6 August 2019|archive-url=https://web.archive.org/web/20190806063256/https://www.nasaspaceflight.com/2018/09/nasa-lunar-gateway-plans/|url-status=live}} It will have a mass of approximately {{cvt|4000|kg}}, and a length of {{cvt|3.91|m}}.Anatoly Zak. [http://www.russianspaceweb.com/imp-lcub.html ESA develops logistics vehicle for cis-lunar outpost] {{Webarchive|url=https://web.archive.org/web/20181004042145/http://russianspaceweb.com/imp-lcub.html|date=4 October 2018}}. RussianSpaceWeb.com, 8 September 2018. ESA has awarded two parallel design studies, one mostly led by Airbus in partnership with Comex and OHB[https://comex.fr/en/2018/11/21/comex-and-airbus-join-forces-around-a-module-of-the-future-lunar-station/ Comex and Airbus join forces around a module of the future lunar station] {{Webarchive|url=https://web.archive.org/web/20190729152604/https://comex.fr/en/2018/11/21/comex-and-airbus-join-forces-around-a-module-of-the-future-lunar-station/|date=29 July 2019}} Comex, press release, 21 November 2018 and one led by Thales Alenia Space.{{cite web|url=https://www.thalesgroup.com/fr/monde-espace/orbital-infrastructure-and-space-transport/magazine/retour-lune-pas-vers-nouvelles|title=Back to the Moon, a step towards future exploration missions|date=5 August 2019 |access-date=7 August 2020|archive-date=22 October 2020|archive-url=https://web.archive.org/web/20201022063112/https://www.thalesgroup.com/fr/monde-espace/orbital-infrastructure-and-space-transport/magazine/retour-lune-pas-vers-nouvelles|url-status=live}} The construction of the module was approved in November 2019.{{Cite web |last=Foust |first=Jeff |date=2 December 2019 |title=Funding Europe's space ambitions |url=https://www.thespacereview.com/article/3843/1 |url-status=live |archive-url=https://web.archive.org/web/20191229115217/https://www.thespacereview.com/article/3843/1 |archive-date=29 December 2019 |access-date= |website=The Space Review}}{{Cite web |last=Hebden |first=Kerry |date=29 November 2019 |title=Hera mission is approved as ESA receives biggest ever budget |url=https://room.eu.com/news/hera-mission-is-approved-as-esa-receives-biggest-ever-budget |archive-url=https://web.archive.org/web/20191210155035/https://room.eu.com/news/hera-mission-is-approved-as-esa-receives-biggest-ever-budget |archive-date=10 December 2019 |access-date= |website=Room The Space Journal of Asgardia}} On 14 October 2020, Thales Alenia Space announced that they had been selected by the European Space Agency (ESA) to build the ESPRIT module.{{cite news |date=2020-10-14 |title=Europe steps up contributions to Artemis Moon plan |url=https://www.bbc.com/news/science-environment-54537906 |url-status=live |archive-url=https://web.archive.org/web/20201014104207/https://www.bbc.com/news/science-environment-54537906 |archive-date=14 October 2020 |access-date=14 October 2020 |work=BBC News}}{{cite web|title=Thales Alenia Space on its way to reach the Moon |url=https://www.thalesgroup.com/en/worldwide/space/press-release/thales-alenia-space-its-way-reach-moon|website=thalesgroup.com|date=14 October 2020 |access-date=14 October 2020}} In early 2021, Thales Alenia Space announced effective contract signature.{{Cite web|url=https://www.thalesgroup.com/en/worldwide/space/news/thales-alenia-space-heart-lunar-industrial-challenges|title=Thales Alenia Space: at the heart of lunar industrial challenges|website=Thales Group|date=7 January 2021 }} The ESPRIT module will consist of two parts. The first part, called Lunar Link{{Cite web |title=Gateway: Lunar Link |url=https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Gateway_Lunar_Link |access-date=2024-06-26 |website=www.esa.int |language=en}} (formerly known as Halo Lunar Communication System – HLCS), will provide the communications for the mini-station Gateway. It will launch in 2027 pre-attached to the HALO module, for which Thales has separately been awarded a contract by NASA to construct its hull and micrometeoroid protection. The second part, called Lunar View{{Cite web |title=Gateway: Lunar View |url=https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Gateway_Lunar_View |access-date=2024-06-26 |website=www.esa.int |language=en}} (formerly known as ESPRIT Refueling Module – ERM), will contain the pressurized fuel tanks, docking ports and small-windowed habitation corridor and launch in 2029.

• {{anchor|I-HAB|International Habitation Module|IHAB}} The Lunar I-HAB{{Cite web |title=Gateway: Lunar I-Hab |url=https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Gateway_Lunar_I-Hab |access-date=2024-06-26 |website=www.esa.int |language=en}} (Lunar International Habitation Module) will be an additional habitation module built by ESA in collaboration with Japan. On 14 October 2020, Thales Alenia Space announced that they had been selected by ESA to build the I-HAB module. The module will include contributions from the other station partners, including a life support system from JAXA, avionics and software from NASA and robotics from the Canadian Space Agency (CSA). The module is slated to launch in 2028 on the Artemis IV mission as a co-manifested payload on the SLS Block 1B along with a crewed Orion spacecraft.{{cite web |last=Foust |first=Jeff |url=https://spacenews.com/nasa-planning-to-spend-up-to-1-billion-on-space-station-deorbit-module/ |title=NASA planning to spend up to $1 billion on space station deorbit module |work=SpaceNews |date=13 March 2023 |access-date=13 March 2023}} The I-HAB would have a maximum launch mass of {{cvt|10000|kg}} and provide a habitable volume of {{cvt|10|m3}} (the gross pressurized volume is {{cvt|35|m3}}.{{cite web |last= |first= |url=https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Orion/Artemis_IV |title=Artemis IV |work=European Space Agency |date= |access-date=26 August 2023}} In 2019, NASA proposed the addition of a second large U.S. habitation module (to be developed by U.S. industry) in order to increase the station's combined habitable volume to {{cvt|125|m3}}.
• {{anchor|Canadarm3|Canadarm 3}} The Canadarm3, a pair of robotic remote manipulator arms, one large and one small, broadly similar to the Space Shuttle Canadarm and International Space Station Canadarm2, and associated dextrous manipulator. The arm is to operate autonomously; however, it is also capable of accepting control from ground stations or from astronauts aboard Gateway.{{Cite web |last=Agency |first=Canadian Space |date=2020-06-26 |title=About Canadarm3 |url=https://www.asc-csa.gc.ca/eng/canadarm3/about.asp |access-date=2023-09-19 |website=Canadian Space Agency}} The Canadarm3 is to be the contribution of the Canadian Space Agency (CSA) to this international endeavor. CSA contracted MDA (formerly MacDonald, Dettwiler and Associates) to build the arm. MDA previously built Canadarm2, while its former subsidiary, Spar Aerospace, built Canadarm.{{cite web |author= |date=26 June 2020 |title=Building the next Canadarm |url=https://www.canada.ca/en/space-agency/news/2020/06/building-the-next-canadarm.html |website=Canadian Space Agency |publisher=Government of Canada}}{{cite news |date=8 December 2020 |title=Canadian Space Agency awards Canadarm3 contract worth $22.8 million to MDA |publisher=CTV News |agency=The Canadian Press |url=https://www.ctvnews.ca/sci-tech/canadian-space-agency-awards-canadarm3-contract-worth-22-8m-to-mda-1.5221827}}{{cite news |author=MDA |date=8 December 2020 |title=MDA Announces Contract for Canadarm3 on NASA-led Gateway |publisher=Yahoo News |agency=CNW |url=https://www.yahoo.com/now/mda-announces-contract-canadarm3-nasa-143000109.html |url-status=dead |access-date=17 December 2020 |archive-url=https://web.archive.org/web/20210428040544/https://www.yahoo.com/now/mda-announces-contract-canadarm3-nasa-143000109.html |archive-date=28 April 2021}}

• {{anchor|Crew and Science Airlock Module}} The Crew and Science Airlock Module will be used for performing extravehicular activities outside the mini-space station and would have the docking port for the proposed Deep space transporter. It will be built by the UAE's Mohammed bin Rashid Space Centre (MBRSC), and is slated for launch around 2030.{{cite web |last=Foust |first=Jeff |url=https://spacenews.com/uae-to-build-airlock-for-lunar-gateway/ |title=UAE to build airlock for lunar Gateway |work=SpaceNews |date=7 January 2024 |access-date=7 January 2024}}

File:Lunar Orbital Platform-Gateway.jpg. The Orion MPCV is docked on the left.]]

The concept for the Gateway is still evolving, and is intended to include the following modules:{{cite web|url=https://www.nasa.gov/sites/default/files/atoms/files/20180327-crusan-nac-heoc-v8.pdf |title=Future Human Exploration Planning:Lunar Orbital Platform – Gateway and Science Workshop Findings|last=Cursan|first=Jason|date=March 27, 2018|access-date=13 April 2018|archive-date=1 June 2019|archive-url=https://web.archive.org/web/20190601195248/https://www.nasa.gov/sites/default/files/atoms/files/20180327-crusan-nac-heoc-v8.pdf|url-status=live}} {{PD-notice}}

• {{anchor|Gateway Logistics Module|Gateway Logistics Modules}} The Gateway Logistics Modules will be used to refuel, resupply and provide logistics on board the mini-space station. The first logistics module sent to the Gateway will also arrive with a robotic arm, which will be built by the Canadian Space Agency (CSA).{{cite news|title=Canada's heading to the moon: A look at the Gateway |url=https://www.cbc.ca/news/technology/canada-lunar-gateway-1.5037522|last1=Mortillaro|first1=Nicole|publisher=CBC News|date=February 28, 2019|access-date=2 March 2019|archive-date=2 March 2019|archive-url=https://web.archive.org/web/20190302004136/https://www.cbc.ca/news/technology/canada-lunar-gateway-1.5037522|url-status=live}}{{cite news|url=https://globalnews.ca/news/3775926/canadian-space-agency-robotic-arms/|title=Canadian Space Agency to build robotic arms for lunar space station|publisher=Global News|access-date=29 September 2017|archive-date=29 September 2017|archive-url=https://web.archive.org/web/20170929130437/https://globalnews.ca/news/3775926/canadian-space-agency-robotic-arms/|url-status=live}}

Crewed flights to the Gateway are expected to use Orion and SLS, while other missions are expected to be done by commercial launch providers. In March 2020, NASA announced SpaceX with its future spacecraft Dragon XL as the first commercial partner to deliver supplies to the Gateway (see Gateway Logistics Services).{{cite web |last=Foust |first=Jeff |url=https://spacenews.com/spacex-wins-nasa-commercial-cargo-contract-for-lunar-gateway/ |title=SpaceX wins NASA commercial cargo contract for lunar Gateway |work=SpaceNews |date=27 March 2020 |access-date=27 March 2020}}

The first two modules (PPE and HALO) will be launched together on a Falcon Heavy rocket no earlier than 2027.{{Cite web |last=Sloss |first=Philip |date=2024-05-23 |title=Initial Gateway elements beginning systems integration while NASA works on a launch date |url=https://www.nasaspaceflight.com/2024/05/gateway-launch-date/ |access-date=2024-05-24 |website=NASASpaceFlight.com |language=en-US}}

NASA officials promote the Gateway as a "reusable command module" that could direct activities on the lunar surface.{{Cite web |last=Foust |first=Jeff |date=2018-12-25 |title=Is the Gateway the right way to the moon? |url=https://spacenews.com/is-the-gateway-the-right-way-to-the-moon/ |access-date=2024-05-08 |website=SpaceNews |language=en-US}} However, Gateway has received some negative reactions.

Michael D. Griffin, a former NASA administrator, said that the Gateway could be useful only after there are facilities on the Moon producing propellant that could be transported to the Gateway. Griffin thinks that after that is achieved, the Gateway would then serve as a fuel depot. In a written testimony to Congress, Griffin stated that the current architecture requiring staging operations at a Gateway based in a lunar polar near-rectilinear halo orbit (NRHO) with a 6.5-day period was disadvantageous in that immediate return to the Gateway from the lunar surface is possible only on 6.5-day centers and that no early human lunar mission should knowingly accept the risk of stranding a crew, whether on the surface or in lunar orbit, for days at a time.{{cite web|last1=Griffin|first1=Michael|title=Returning to the Moon: Keeping Artemis on Track|url=https://republicans-science.house.gov/_cache/files/2/d/2dc97bb6-040b-4d15-ae69-6b8de637174d/448A0B95841995613C9A9B19135C104C.2024-01-17-griffin---testimony.pdf/|date=17 January 2024|access-date=19 January 2024}}

Clive Neal, a University of Notre Dame geologist and advocate for the lunar exploration program, called the Gateway "a waste of money" and stated that NASA is "not fulfilling space policy by building an orbital space station around the Moon".{{cite web|last1=Berger|first1=Eric|author-link=Eric Berger (meteorologist)|title=We got a leaked look at NASA's future Moon missions—and likely delays|url=https://arstechnica.com/science/2022/06/we-got-a-leaked-look-at-nasas-future-moon-missions-and-likely-delays/|newspaper=Ars Technica|date=20 June 2022|access-date=27 June 2020}}

Former NASA Associate Administrator Doug Cooke wrote in an article on The Hill stating, "NASA can significantly increase speed, simplicity, cost and probability of mission success by deferring Gateway, leveraging SLS, and reducing critical mission operations". He also wrote, "NASA should launch the lander elements (ascent and descent/transfer) on an SLS Block 1B. If an independent transfer element is required, it can be launched on a commercial launcher".{{cite web|last1=Cooke|first1=Doug|title=Getting back to the moon requires speed and simplicity |url=https://thehill.com/opinion/technology/461299-getting-back-to-the-moon-requires-speed-and-simplicity|newspaper=The Hill|date=13 September 2019|access-date=20 September 2019|archive-date=20 September 2019|archive-url=https://web.archive.org/web/20190920121323/https://thehill.com/opinion/technology/461299-getting-back-to-the-moon-requires-speed-and-simplicity|url-status=live}}

George Abbey, a former director of NASA's Johnson Space Center, said, "The Gateway is, in essence, building a space station to orbit a natural space station, namely the Moon. [...] If we are going to return to the Moon, we should go directly there, not build a space station to orbit it".{{cite news |last1=Abbey |first1=George |date=13 July 2019 |title=The Moon is "a God-given space station orbiting Earth" [Opinion] |url=https://www.houstonchronicle.com/opinion/outlook/article/The-moon-is-a-God-given-space-station-orbiting-14092345.php |url-status=live |archive-url=https://web.archive.org/web/20190920155132/https://www.houstonchronicle.com/opinion/outlook/article/The-moon-is-a-God-given-space-station-orbiting-14092345.php |archive-date=20 September 2019 |access-date=20 September 2019 |language=en-us |publication-place=Houston, Texas |newspaper=Houston Chronicle}}

Former NASA astronaut Terry W. Virts, who was a pilot of STS-130 aboard {{OV|105}} and commander of the ISS on Expedition 43, wrote in an op-ed on Ars Technica that the Gateway would "shackle human exploration, not enable it". He also said, "If we don't have the goal [of Gateway], we are putting the proverbial chicken before the egg by developing "Gemini" before we know what "Apollo" will look like. Regardless of a future destination, as someone who lived on the ISS for 200 days, I cannot envision a new technology that would be developed or validated by building another modular space station. Without a specific goal, we're unlikely to ever identify one". Virts further criticized NASA for abandoning its planned goal of separating crew from cargo, which was put in place following the Space Shuttle Columbia disaster in 2003.{{cite web|title=Op-ed: The Deep Space Gateway would shackle human exploration, not enable it|date=28 September 2017|url=https://arstechnica.com/science/2017/09/op-ed-the-deep-space-gateway-would-shackle-human-exploration-not-enable-it/|publisher=Ars Technica|access-date=20 May 2018|archive-date=21 May 2018|archive-url=https://web.archive.org/web/20180521104209/https://arstechnica.com/science/2017/09/op-ed-the-deep-space-gateway-would-shackle-human-exploration-not-enable-it/|url-status=live}}

Apollo 11 astronaut Buzz Aldrin stated that he is "quite opposed to the Gateway" and that "using the Gateway as a staging area for robotic or human missions to the lunar surface is absurd". Aldrin also questioned the benefit of the idea of sending "a crew to an intermediate point in space, pick up a lander there and go down". Conversely, Aldrin expressed support for Robert Zubrin's Moon Direct concept which involves lunar landers traveling from Earth orbit to the lunar surface and back.{{cite web|url=https://spacenews.com/advisory-group-skeptical-of-nasa-lunar-exploration-plans/ |title=Advisory group skeptical of NASA lunar exploration plans|last1=Foust|first1=Jeff|date=16 November 2018|publisher=SpaceNews|access-date=20 December 2018}}

Architect René Waclavicek, who was involved with the design of the I-HAB module, noted the difficulty of designing a comfortable living quarter for astronauts visiting Gateway. His team was forced to shrink the size of the module to the point where its diameter is just 1.2 meters (4 feet), owing to the limited amount of weight current launch vehicles can carry to Lunar orbit and other technical limits. Additionally, most of I-HAB's 8 cubic meters (280 cubic feet) of available space will be filled with life support equipment, leaving a narrow corridor and a total of 1.5 cubic meters (53 cubic feet) of personal space to be shared by four astronauts.{{Cite web |last=Pultarova |first=Tereza |date=2023-01-08 |title=NASA's moon-orbiting space station will be claustrophobic, architect says |url=https://www.space.com/lunar-gateway-station-claustrophobic-architect-says |access-date=2023-04-04 |website=Space.com |language=en}}

Mars Society founder Robert Zubrin called the Gateway "NASA's worst plan yet" in an article in the National Review. He said, "We do not need a lunar-orbiting station to go to the Moon. We do not need such a station to go to Mars. We do not need it to go to near-Earth asteroids. We do not need it to go anywhere. Nor can we accomplish anything in such a station that we cannot do in the Earth-orbiting International Space Station, except to expose human subjects to irradiation – a form of medical research for which a number of Nazi doctors were hanged". Zubrin also stated, "If the goal is to build a Moon base, it should be built on the surface of the Moon. That is where the science is, that is where the shielding material is, and that is where the resources to make propellant and other useful things are to be found".{{cite web|title=NASA's Worst Plan Yet|date=16 May 2017 |url=https://www.nationalreview.com/2017/05/nasa-lunar-orbit-space-station-terrible-idea/ |publisher=National Review|access-date=20 May 2018|archive-date=2 March 2018|archive-url=https://web.archive.org/web/20180302014801/https://www.nationalreview.com/2017/05/nasa-lunar-orbit-space-station-terrible-idea/|url-status=live}}

Retired aerospace engineer Gerald Black wrote in an article on The Space Review stating that the Gateway is "useless for supporting human return to the lunar surface and a lunar base". He added that it was not planned to be used as a rocket fuel depot and that stopping at the Gateway on the way to or from the Moon would serve no useful purpose and cost propellant.Gerald Black. [http://thespacereview.com/article/3494/1 The Lunar Orbital Platform – Gateway: an unneeded and costly diversion], {{Webarchive|url=https://web.archive.org/web/20180521104510/http://thespacereview.com/article/3494/1|date=21 May 2018}}. The Space Review, 14 May 2018.

Mark Whittington, a contributor to The Hill newspaper and an author of several space exploration studies, stated in an article that the "lunar orbit project doesn't help us get back to the Moon". Whittington also pointed out that a lunar orbiting space station was not used during the Apollo program and that a "reusable lunar lander could be refueled from a depot on the lunar surface and left in a parking orbit between missions without the need for a big, complex space station".{{cite web|last1=Whittington|first1=Mark|title=NASA's unnecessary US$504 million lunar orbit project doesn't help us get back to the Moon|url=https://thehill.com/opinion/technology/392611-nasas-unnecessary-504-million-lunar-orbit-project-doesnt-help-us-get-back|newspaper=The Hill|date=16 June 2018|access-date=20 December 2018|archive-date=14 November 2019|archive-url=https://web.archive.org/web/20191114223317/https://thehill.com/opinion/technology/392611-nasas-unnecessary-504-million-lunar-orbit-project-doesnt-help-us-get-back|url-status=live}}

Astrophysicist Ethan Siegel wrote an article in Forbes titled "NASA's Idea For A Space Station In Lunar Orbit Takes Humanity Nowhere". Siegel stated that "Orbiting the Moon represents barely incremental progress; the only scientific "advantages" to being in lunar orbit as opposed to low Earth orbit are twofold: 1. You're outside of the Van Allen belts. 2. You're closer to the lunar surface", reducing the time delay. His final opinion was that the Gateway is "a great way to spend a great deal of money, advancing science and humanity in no appreciable way".{{cite web|last1=Siegel|first1=Ethan|title=NASA's Idea For A Space Station In Lunar Orbit Takes Humanity Nowhere|url=https://www.forbes.com/sites/startswithabang/2017/05/18/nasas-idea-for-a-space-station-in-lunar-orbit-takes-humanity-nowhere/#221e7593d145 |work=Forbes|access-date=15 February 2019|archive-date=16 February 2019|archive-url=https://web.archive.org/web/20190216153303/https://www.forbes.com/sites/startswithabang/2017/05/18/nasas-idea-for-a-space-station-in-lunar-orbit-takes-humanity-nowhere/#221e7593d145|url-status=live}}

On July 31, 2024, the United States Government Accountability Office found that the Gateway has run into technical problems in its communications and propulsion systems which have yet to be addressed by NASA. Its proposed 15-year lifespan is also considered to be too short to properly support a manned mission to Mars.{{cite web|last1=Berger|first1=Eric|title=NASA’s Lunar Gateway has a big visiting vehicles problem |url=https://arstechnica.com/space/2024/08/nasas-lunar-gateway-has-a-big-visiting-vehicles-problem/ |work=Ars Technica|date=1 August 2024|access-date=5 January 2025|url-status=live}}{{cite web|title=Artemis Programs: NASA Should Document and Communicate Plans to Address Gateway's Mass Risk |url=https://www.gao.gov/assets/gao-24-106878.pdf |work=GAO|date=31 July 2024|access-date=5 January 2025|url-status=live}}

On 10 December 2018, NASA Administrator Jim Bridenstine said at a presentation "There are people who say we need to get there, and we need to get there tomorrow", speaking of a crewed mission to the Moon, countering with "What we're doing here at NASA is following Space Policy Directive 1", speaking of the Gateway and following up with "I would argue that we got there in 1969. That race is over, and we won. The time now is to build a sustainable, reusable architecture. [...] The next time we go to the Moon, we're going to have American boots on the Moon with the American flag on their shoulders, and they're going to be standing side-by-side with our international partners who have never been to the Moon before".{{cite web|website=spacenews.com|date=15 December 2018|title=Is the Gateway the right way to the moon?|first=Jeff|last=Foust|url=https://spacenews.com/is-the-gateway-the-right-way-to-the-moon/|access-date=20 August 2019}}

Dan Hartman, the program manager for Gateway, on 30 March 2020, told Ars Technica that the benefits of using Gateway are extending the mission duration, buying down risk, providing research capability and the capability to re-use ascent modules.

When you go single, I'll say direct mission to the Moon, you're limited on the supplies, either with the Lander or with Orion. With the Gateway, with just with one logistics module, we think we can extend to about twice the mission duration, so 30 days to 60 days. Obviously, the more crew time you have in lunar orbit helps us with research in the human aspects of living in deep space. The more duration we have, certainly that'll help us buy down significant risk with the extreme environments that we're going to be subjecting our crews to. Because we've got to go figure out how to operate in deep space. Obviously we'll demonstrate new hardware and offer that sustainable flexible path for our Lunar Lander system. With the Gateway, the thinking is we'll be able to reuse the ascent modules potentially multiple times. And again, if we can get mission duration beyond the 30 days, it's going to offer us some additional environmental capabilities. We think it's a tremendous risk buy down asset, not only to explore the Moon sustainably, but to prove out some things that we need to do to get to Mars.{{cite web |last1=Berger |first1=Eric |date=30 March 2020 |title=NASA officials outline plans for building a lunar Gateway in the mid-2020s |url=https://arstechnica.com/science/2020/03/nasa-officials-outline-plans-for-building-a-lunar-gateway-in-the-mid-2020s/ |url-status=live |archive-url=https://web.archive.org/web/20200513134610/https://arstechnica.com/science/2020/03/nasa-officials-outline-plans-for-building-a-lunar-gateway-in-the-mid-2020s/ |archive-date=13 May 2020 |access-date=25 April 2020 |publisher=Ars Technica}}

On May 2, 2025, the Trump administration released its fiscal year 2026 budget proposal for NASA, which calls for ending the Gateway program and potentially repurposing already produced components for use in other missions.{{Cite news |last=Berger |first=Eric |author-link=Eric Berger (journalist) |date=2 May 2025 |title=White House budget seeks to end SLS, Orion, and Lunar Gateway programs |url=https://arstechnica.com/space/2025/05/white-house-budget-seeks-to-end-sls-orion-and-lunar-gateway-programs/ |access-date=2 May 2025 |work=Ars Technica}}{{Cite press release |title=President Trump's FY26 Budget Revitalizes Human Space Exploration |date=2 May 2025 |publisher=NASA |url=https://www.nasa.gov/news-release/president-trumps-fy26-budget-revitalizes-human-space-exploration/ |last1=Dooren |first1=Jennifer M. |last2=Stevens |first2=Bethany |access-date=2 May 2025}}{{Cite web |date=2 May 2025 |title=Fiscal Year 2026 Discretionary Budget Request |url=https://www.whitehouse.gov/wp-content/uploads/2025/05/Fiscal-Year-2026-Discretionary-Budget-Request.pdf |access-date=2 May 2025 |website=United States Office of Management and Budget |page=37}}

{{Portal|Spaceflight}}

• {{Annotated link|CAPSTONE (spacecraft)}}
• {{Annotated link|Commercial Resupply Services}}
• {{Annotated link|Exploration Gateway Platform}}
• {{Annotated link|Lunar Orbital Station}}
• {{Annotated link|Moonbase}}
• {{Annotated link|Lunar cycler}}
• {{Annotated link|Orbital Piloted Assembly and Experiment Complex}}
• {{Annotated link|Project Prometheus}}
• {{Annotated link|Mars Base Camp}}
• {{Annotated link|Mars Piloted Orbital Station}}
• {{Annotated link|Starship HLS}}
• {{Annotated link|International Lunar Research Station}}

{{Reflist}}

• [https://www.nasa.gov/feature/deep-space-gateway-to-open-opportunities-for-distant-destinations Deep Space Gateway to Open Opportunities for Distant Destinations] – NASA Moon to Mars
• [http://www.russianspaceweb.com/imp.html First human outpost near the Moon] – RussianSpaceWeb page about the Gateway
• [http://www.russianspaceweb.com/imp-2017.html History of the Gateway planning]

{{NASA space program}}

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{{Moon spacecraft}}

{{Artemis program}}

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