Phoenix (spacecraft)#Confirmation of presence of shallow subsurface ice

The mission had two goals. One was to study the geological history of water, the key to unlocking the story of past climate change. The second was to evaluate past or potential planetary habitability in the ice-soil boundary. Phoenix's instruments were suitable for uncovering information on the geological and possibly biological history of the Martian Arctic. Phoenix was the first mission to return data from either of the poles, and contributed to NASA's main strategy for Mars exploration, "Follow the water."

The primary mission was anticipated to last 90 sols (Martian days)—just over 92 Earth days. However, the craft exceeded its expected operational lifetime{{Cite web |last=Beatty |first=J. Kelly |date=September 5, 2008 |title=Phoenix Surpasses 90-Day Mileston |url=https://skyandtelescope.org/astronomy-news/phoenix-surpasses-90-day-milestone/ |url-status=live |archive-url=https://web.archive.org/web/20211206235223/https://skyandtelescope.org/astronomy-news/phoenix-surpasses-90-day-milestone/ |archive-date=December 6, 2021 |access-date=August 1, 2012 |website=SkyandTelescope.com }} by a little over two months before succumbing to the increasing cold and dark of an advancing Martian winter. Researchers had hoped that the lander would survive into the Martian winter so that it could witness polar ice developing around it – perhaps up to {{convert|1|m|ft|sigfig=1|sp=us}} of solid carbon dioxide ice could have appeared. Even had it survived some of the winter, the intense cold would have prevented it from lasting all the way through.{{Cite news |last=David |first=Leonard |date=February 1, 2007 |title=Phoenix Lander Readied For Mars Exploration |url=https://www.space.com/3409-phoenix-lander-readied-mars-exploration.html |url-status=live |archive-url=https://web.archive.org/web/20230927083735/https://www.space.com/3409-phoenix-lander-readied-mars-exploration.html |archive-date=September 27, 2023 |access-date=February 12, 2023 |work=Space.com }} The mission was chosen to be a fixed lander rather than a rover because:{{cite episode|title=The Phoenix Mars Mission with Dr. Deborah Bass|series=Futures in Biotech podcast|airdate=September 19, 2007|number=24}}

• costs were reduced through reuse of earlier equipment (though this claim is disputed by some observers{{Cite web |last=Cowing |first=Keith |date=June 3, 2005 |title=NASA Has a Problem Calculating – and Admitting – What Space Missions Really Cost |url=https://spaceref.com/uncategorized/nasa-has-a-problem-calculating-and-admitting-what-space-missions-really-cost/ |url-status=live |archive-url=https://archive.today/20240110093111/https://spaceref.com/uncategorized/nasa-has-a-problem-calculating-and-admitting-what-space-missions-really-cost/ |archive-date=January 10, 2024 |access-date=September 29, 2014 |website=SpaceRef }});
• the area of Mars where Phoenix landed is thought to be relatively uniform, thus traveling on the surface is of less value; and
• the weight budget needed for mobility could instead be used for more and better scientific instruments.

The 2003–2004 observations of methane gas on Mars were made remotely by three teams working with separate data. If the methane is truly present in the atmosphere of Mars, then something must be producing it on the planet now, because the gas is broken down by radiation on Mars within 300 years;{{Cite journal |last1=Mumma |first1=M. J. |last2=Novak |first2=R. E. |last3=DiSanti |first3=M. A. |last4=Bonev |first4=B. P. |date=May 2003 |title=A Sensitive Search for Methane on Mars |url=https://www.researchgate.net/publication/253596761 |url-status=live |journal=AAS/Division for Planetary Sciences Meeting Abstracts |volume=35 |issue=5917 |pages=1041–1045 |bibcode=2003DPS....35.1418M |doi=10.1126/science.1165243 |pmid=19150811 |archive-url=https://web.archive.org/web/20240110093507/https://www.researchgate.net/profile/R-Novak/publication/253596761_A_Sensitive_Search_for_Methane_on_Mars/links/55bb81a208aec0e5f44188b1/A-Sensitive-Search-for-Methane-on-Mars.pdf |archive-date=January 10, 2024 }}{{cite web|title=Mars Methane Boosts Chances for Life|author=Michael J. Mumma|publisher=Skytonight.com|url=http://www-mgcm.arc.nasa.gov/MGCM.html|access-date=February 23, 2007|url-status=dead|archive-url=https://web.archive.org/web/20070220100252/http://www-mgcm.arc.nasa.gov/MGCM.html|archive-date=February 20, 2007}}{{cite journal |doi=10.1126/science.1101732 |pmid=15514118 |title=Detection of Methane in the Atmosphere of Mars |journal=Science |volume=306 |issue=5702 |pages=1758–61 |year=2004 |last1=Formisano |first1=V |last2=Atreya |first2=Sushil |last3=Encrenaz |first3=Thérèse |author3-link=Thérèse Encrenaz|last4=Ignatiev |first4=Nikolai |last5=Giuranna |first5=Marco |bibcode=2004Sci...306.1758F |s2cid=13533388 |doi-access=free }}{{cite journal |doi=10.1016/j.icarus.2004.07.004 |title=Detection of methane in the martian atmosphere: Evidence for life? |journal=Icarus |volume=172 |issue=2 |pages=537–47 |year=2004 |last1=Krasnopolsky |first1=Vladimir A |last2=Maillard |first2=Jean Pierre |last3=Owen |first3=Tobias C |bibcode=2004Icar..172..537K }}{{Cite press release |date=March 30, 2004 |title=Mars Express confirms methane in the Martian atmosphere |url=https://www.esa.int/Science_Exploration/Space_Science/Mars_Express/Mars_Express_confirms_methane_in_the_Martian_atmosphere |url-status=live |archive-url=https://web.archive.org/web/20230919181142/https://www.esa.int/Science_Exploration/Space_Science/Mars_Express/Mars_Express_confirms_methane_in_the_Martian_atmosphere |archive-date=September 19, 2023 |access-date=March 17, 2006 |publisher=ESA }} therefore, it was considered important to determine the biological potential or habitability of the Martian arctic's soils.{{cite web|url=http://phoenix.lpl.arizona.edu/mars143.php |title=Phoenix Mars Mission – Habitability and Biology – Methane |publisher=Phoenix.lpl.arizona.edu |date=February 29, 2008 |access-date=July 13, 2012| archive-url= https://web.archive.org/web/20070122183601/http://phoenix.lpl.arizona.edu:80/mars143.php | archive-date= 22 January 2007 | url-status= dead}} Methane could also be the product of a geochemical process or the result of volcanic or hydrothermal activity.{{cite web|url=http://astrobio.net/news/modules.php?op=modload&name=News&file=article&sid=2765&mode=thread&order=0&thold=0 |title=Making Sense of Mars Methane | author1= David Tenenbaum| date= June 2008|work=Astrobiology Magazine |access-date=July 13, 2012 |archive-url=https://web.archive.org/web/20120531234217/http://www.astrobio.net/exclusive/2765/making-sense-of-mars-methane |archive-date=2012-05-31 |url-status=dead}}

While the proposal for Phoenix was being written, the Mars Odyssey orbiter used its gamma-ray spectrometer and found the distinctive signature of hydrogen on some areas of the Martian surface, and the only plausible source of hydrogen on Mars would be water in the form of ice, frozen below the surface. The mission was therefore funded on the expectation that Phoenix would find water ice on the arctic plains of Mars.{{Cite news |date=August 19, 2008 |title=Phoenix diary: Mission to Mars |url=http://news.bbc.co.uk/2/hi/science/nature/7408033.stm |url-status=live |archive-url=https://web.archive.org/web/20230531010521/http://news.bbc.co.uk/2/hi/science/nature/7408033.stm |archive-date=May 31, 2023 |access-date=July 13, 2012 |work=BBC News }} In August 2003 NASA selected the University of Arizona "Phoenix" mission for launch in 2007. It was hoped this would be the first in a new line of smaller, low-cost, Scout missions in the agency's exploration of Mars program.{{Cite press release |last1=Webster |first1=Guy |last2=Stiles |first2=Lori |last3=Savage |first3=Donald |date=August 4, 2003 |title=Mars 2007 'Phoenix' will Study Water near Mars' North Pole |url=https://www.jpl.nasa.gov/news/mars-2007-phoenix-will-study-water-near-mars-north-pole |url-status=live |archive-url=https://web.archive.org/web/20240110094919/https://www.jpl.nasa.gov/news/mars-2007-phoenix-will-study-water-near-mars-north-pole |archive-date=January 10, 2024 |publisher=Jet Propulsion Laboratory |id=2003-107 }} The selection was the result of an intense two-year competition with proposals from other institutions. The $325 million NASA award is more than six times larger than any other single research grant in University of Arizona history.

File:Phoenix_17_sol_20_to_24_change_dodo.jpg

Peter H. Smith of the University of Arizona Lunar and Planetary Laboratory, as Principal Investigator, along with 24 Co-Investigators, were selected to lead the mission. The mission was named after the Phoenix, a mythological bird that is repeatedly reborn from its own ashes. The Phoenix spacecraft contains several previously built components. The lander used was the modified Mars Surveyor 2001 Lander (canceled in 2000), along with several of the instruments from both that and the previous unsuccessful Mars Polar Lander mission. Lockheed Martin, who built the lander, had kept the nearly complete lander in an environmentally controlled clean room from 2001 until the mission was funded by the NASA Scout Program.{{cite web|title=Phoenix Mars Lander- Spacecraft|website=Phoenix Mars Lander|url=http://phoenix.lpl.arizona.edu/science_spacecraft.php

| archive-url= https://web.archive.org/web/20070204073339/http://phoenix.lpl.arizona.edu/science_spacecraft.php | archive-date= 4 February 2007

|access-date=June 9, 2006}}

File:Sojourner, MER, Phoenix lander, and Curiosity comparisons, in Metric units.jpg, the Mars Exploration Rovers, the Phoenix lander and the Mars Science Laboratory.]]

Phoenix was a partnership of universities, NASA centers, and the aerospace industry. The science instruments and operations were a University of Arizona responsibility. NASA's Jet Propulsion Laboratory in Pasadena, California, managed the project and provided mission design and control. Lockheed Martin Space Systems built and tested the spacecraft. The Canadian Space Agency provided a meteorological station, including an innovative laser-based atmospheric sensor.[https://passatltd.com/wp-content/uploads/2012/05/CSA-Certificate-Recognition1.jpg "Certificate of Recognition"] Passat Ltd.[https://passatltd.com website]. Retrieved October 1, 2012. {{webarchive |url=https://web.archive.org/web/20140730193559/http://passatinc.com/certificate-of-recognition/ |date=July 30, 2014 }} The co-investigator institutions included Malin Space Science Systems (California), Max Planck Institute for Solar System Research (Germany), NASA Ames Research Center (California), NASA Johnson Space Center (Texas), MacDonald, Dettwiler and Associates (Canada), Optech Incorporated (Canada), SETI Institute, Texas A&M University, Tufts University, University of Colorado, University of Copenhagen (Denmark), University of Michigan, University of Neuchâtel (Switzerland), University of Texas at Dallas, University of Washington, Washington University in St. Louis, and York University (Canada). Scientists from Imperial College London and the University of Bristol provided hardware for the mission and were part of the team operating the microscope station.{{Cite press release |last=Short |first=Julia |date=May 15, 2008 |title=Phoenix probe due to touch down on Martian surface |url=http://www.scitech.ac.uk/PMC/PRel/STFC/phoenix1.aspx |url-status=dead |archive-url=https://web.archive.org/web/20080521031734/http://www.scitech.ac.uk/PMC/PRel/STFC/phoenix1.aspx |archive-date=May 21, 2008 |access-date=May 17, 2008 |publisher=Science and Technology Facilities Council }}File:070802 phoenix lab 02.jpg

On June 2, 2005, following a critical review of the project's planning progress and preliminary design, NASA approved the mission to proceed as planned.{{Cite press release |last1=Beasley |first1=Dolores |last2=Webster |first2=Guy |last3=Stiles |first3=Lori |date=June 2, 2005 |title=NASA's Phoenix Mars Mission Begins Launch Preparations |url=https://nssdc.gsfc.nasa.gov/planetary/text/phoenix_pr_20050602.txt |url-status=live |archive-url=https://web.archive.org/web/20161222235126/http://nssdc.gsfc.nasa.gov/planetary/text/phoenix_pr_20050602.txt |archive-date=December 22, 2016 |access-date=April 2, 2006 |publisher=NASA |id=05-141 }} The purpose of the review was to confirm NASA's confidence in the mission.

;File:Phoenix Mars Lander in testing PIA01885.jpgLaunched mass

:{{convert|670|kg|lb|abbr=on}} Includes Lander, Aeroshell (backshell and heatshield), parachutes, cruise stage.

;Lander Mass

:{{convert|350|kg|lb|abbr=on}}

;Lander Dimensions

:About {{convert|5.5|m|ft|abbr=on}} long with the solar panels deployed. The science deck by itself is about {{convert|1.5|m|ft|abbr=on}} in diameter. From the ground to the top of the MET mast, the lander measures about {{convert|2.2|m|ft|abbr=on}} tall.

;Communications

:X-band throughout the cruise phase of the mission and for its initial communication after separating from the third stage of the launch vehicle. UHF links, relayed through Mars orbiters during the entry, descent and landing phase and while operating on the surface of Mars. The UHF system on Phoenix is compatible with relay capabilities of NASA's Mars Odyssey, Mars Reconnaissance Orbiter and with the European Space Agency's Mars Express. The interconnections use the Proximity-1 protocol.{{cite web|url=http://phoenix.lpl.arizona.edu/faq.php|title=Phoenix Mars Mission FAQ|access-date=May 25, 2008| archive-url= https://web.archive.org/web/20070204073319/http://phoenix.lpl.arizona.edu/faq.php | archive-date= 4 February 2007 | url-status=dead}}

;Power

:Power for the cruise phase is generated using two decagonal gallium arsenide solar panels (total area {{convert|3.1|m2|ft2|abbr=on}}) mounted to the cruise stage, and for the lander, via two gallium arsenide solar array panels (total area {{convert|7.0|m2|ft2|abbr=on}}) deployed from the lander after touchdown on the Martian surface. NiH₂ battery with a capacity of 16 A·h.{{cite news|url=http://blog.gogreensolar.com/2008/05/phoenix-mars-lander-spreads-it-solar.html|title=Phoenix Mars Lander spreads its solar power wings|date=May 25, 2008|access-date=November 1, 2008|publisher=Go Green Solar|archive-date=June 5, 2008|archive-url=https://web.archive.org/web/20080605210803/http://blog.gogreensolar.com/2008/05/phoenix-mars-lander-spreads-it-solar.html|url-status=dead}}

Lander systems include a RAD6000 based computer system for commanding the spacecraft and handling data.{{cite web|url=http://www.technologynewsdaily.com/node/7629|title=Power Architecture onboard Phoenix Mars Lander|website=Technology News Daily|archive-url=https://web.archive.org/web/20090316041121/http://www.technologynewsdaily.com/node/7629|archive-date=March 16, 2009|access-date=April 13, 2008|url-status=dead}} Other parts of the lander are an electrical system containing solar arrays and batteries, a guidance system to land the spacecraft, eight {{convert|1.0|lbf|abbr=on|order=flip}} and {{convert|5.0|lbf|abbr=on|order=flip}} monopropellant hydrazine engines built by Aerojet-Redmond Operations for the cruise phase, twelve {{convert|68.0|lbf|abbr=on|order=flip}} Aerojet monopropellant hydrazine thrusters to land the Phoenix, mechanical and structural elements, and a heater system to ensure the spacecraft does not get too cold.

File:Phoenix Mars Lander.jpg. Each Martian day is 40 minutes longer than an Earth Day.]]

Phoenix carried improved versions of University of Arizona panoramic cameras and volatiles-analysis instrument from the ill-fated Mars Polar Lander, as well as experiments that had been built for the canceled Mars Surveyor 2001 Lander, including a JPL trench-digging robotic arm, a set of wet chemistry laboratories, and optical and atomic force microscopes. The science payload also included a descent imager and a suite of meteorological instruments.{{cite journal |doi=10.1016/j.actaastro.2005.03.038 |pmid=16010756 |title=Phoenix—the first Mars Scout mission |journal=Acta Astronautica |volume=57 |issue=2–8 |pages=121–134 |year=2005 |last1=Shotwell |first1=Robert |bibcode=2005AcAau..57..121S |s2cid=972265 }}

During EDL, the Atmospheric Structure Experiment was conducted. This used accelerometer and gyroscope data recorded during the lander's descent through the atmosphere to create a vertical profile of the temperature, pressure, and density of the atmosphere above the landing site, at that point in time.{{Cite journal |last1=Withers |first1=Paul |last2=Catling |first2=D.C. |date=December 23, 2010 |title=Observations of atmospheric tides on Mars at the season and latitude of the Phoenix atmospheric entry |url=https://faculty.washington.edu/dcatling/Withers2010_CatlingGRL.pdf |url-status=live |journal=Geophysical Research Letters |volume=37 |issue=24 |bibcode=2010GeoRL..3724204W |doi=10.1029/2010GL045382 |archive-url=https://web.archive.org/web/20220123144305/https://faculty.washington.edu/dcatling/Withers2010_CatlingGRL.pdf |archive-date=January 23, 2022 |doi-access=free }}

File:Arm Stowed.jpg

The robotic arm was designed to extend {{cvt|2.35|m|ft}} from its base on the lander, and had the ability to dig down to {{cvt|0.5|m|ft}} below a sandy surface. It took samples of dirt and ice that were analyzed by other instruments on the lander. The arm was designed and built for the Jet Propulsion Laboratory by Alliance Spacesystems, LLC{{cite web|url=http://www.alliancespacesystems.com/index.php?option=com_content&task=view&id=121&Itemid=130|archive-url=https://web.archive.org/web/20110515101513/http://www.alliancespacesystems.com/index.php?option=com_content&task=view&id=121&Itemid=130|url-status=dead|archive-date=May 15, 2011|publisher=Alliance Spacesystems|title=Mars '01 Robotic Arm|access-date=May 25, 2008}} (now Maxar Space Robotics, LLC) in Pasadena, California. A rotating rasp-tool located in the heel of the scoop was used to cut into the strong permafrost. Cuttings from the rasp were ejected into the heel of the scoop and transferred to the front for delivery to the instruments. The rasp tool was conceived of at the Jet Propulsion Laboratory. The flight version of the rasp was designed and built by HoneyBee Robotics. Commands were sent for the arm to be deployed on May 28, 2008, beginning with the pushing aside of a protective covering intended to serve as a redundant precaution against potential contamination of Martian soil by Earthly life-forms.

The Robotic Arm Camera (RAC) attached to the robotic arm just above the scoop was able to take full-color pictures of the area, as well as verify the samples that the scoop returned, and examined the grains of the area where the robotic arm had just dug. The camera was made by the University of Arizona and Max Planck Institute for Solar System Research,{{cite web|url=http://www.mps.mpg.de/en/projekte/phoenix/rac/ |title=RAC Robotic Arm Camera |publisher=Max Planck Institute for Solar System Research |url-status=dead |archive-url=https://web.archive.org/web/20120410015404/http://www.mps.mpg.de/en/projekte/phoenix/rac/ |archive-date=April 10, 2012 }} Germany.{{cite journal |doi=10.1029/1999JE001123 |title=The MVACS Robotic Arm Camera |journal=Journal of Geophysical Research: Planets |volume=106 |issue=E8 |pages=17609–22 |year=2001 |last1=Keller |first1=H. U |last2=Hartwig |first2=H |last3=Kramm |first3=R |last4=Koschny |first4=D |last5=Markiewicz |first5=W. J |last6=Thomas |first6=N |last7=Fernades |first7=M |last8=Smith |first8=P. H |last9=Reynolds |first9=R |last10=Lemmon |first10=M. T |last11=Weinberg |first11=J |last12=Marcialis |first12=R |last13=Tanner |first13=R |last14=Boss |first14=B. J |last15=Oquest |first15=C |last16=Paige |first16=D. A |bibcode=2001JGR...10617609K |doi-access=free }}

File:181451main surface stereo imager-hires.jpg

The Surface Stereo Imager (SSI) was the primary camera on the lander. It is a stereo camera that is described as "a higher resolution upgrade of the imager used for Mars Pathfinder and the Mars Polar Lander".{{cite web|title=Phoenix Mars Lander- SSI |website=Phoenix Mars Lander |url=http://phoenix.lpl.arizona.edu/technology/ssi.php |access-date=May 25, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20061011012548/http://phoenix.lpl.arizona.edu/technology/ssi.php |archive-date=October 11, 2006 }} It took several stereo images of the Martian Arctic, and also used the Sun as a reference to measure the atmospheric distortion of the Martian atmosphere due to dust, air and other features. The camera was provided by the University of Arizona in collaboration with the Max Planck Institute for Solar System Research.{{cite journal |doi=10.1029/1999JE001116 |title=The MVACS Surface Stereo Imager on Mars Polar Lander |journal=Journal of Geophysical Research: Planets |volume=106 |issue=E8 |pages=17589–608 |year=2001 |last1=Smith |first1=P. H |last2=Reynolds |first2=R |last3=Weinberg |first3=J |last4=Friedman |first4=T |last5=Lemmon |first5=M. T |last6=Tanner |first6=R |last7=Reid |first7=R. J |last8=Marcialis |first8=R. L |last9=Bos |first9=B. J |last10=Oquest |first10=C |last11=Keller |first11=H. U |last12=Markiewicz |first12=W. J |last13=Kramm |first13=R |last14=Gliem |first14=F |last15=Rueffer |first15=P |bibcode=2001JGR...10617589S |s2cid=58887184 |doi-access=free }}{{cite journal |doi=10.1109/19.903879 |title=The design of Mars lander cameras for Mars Pathfinder, Mars Surveyor '98 and Mars Surveyor '01 |journal=IEEE Transactions on Instrumentation and Measurement |volume=50 |issue=1 |pages=63–71 |year=2001 |last1=Reynolds |first1=R.O |last2=Smith |first2=P.H |last3=Bell |first3=L.S |last4=Keller |first4=H.U |bibcode=2001ITIM...50...63R }}

File:183833main wb1-tega-hires.jpg

The Thermal and Evolved Gas Analyzer (TEGA) is a combination of a high-temperature furnace with a mass spectrometer. It was used to bake samples of Martian dust and determine the composition of the resulting vapors. It has eight ovens, each about the size of a large ball-point pen, which were able to analyze one sample each, for a total of eight separate samples. Team members measured how much water vapor and carbon dioxide gas were given off, how much water ice the samples contained, and what minerals are present that may have formed during a wetter, warmer past climate. The instrument also measured organic volatiles, such as methane, down to 10 parts per billion. TEGA was built by the University of Arizona and University of Texas at Dallas.{{cite journal |doi=10.1029/1999JE001153 |title=Thermal and Evolved Gas Analyzer: Part of the Mars Volatile and Climate Surveyor integrated payload |journal=Journal of Geophysical Research: Planets |volume=106 |issue=E8 |pages=17683–98 |year=2001 |last1=Boynton |first1=William V |last2=Bailey |first2=Samuel H |last3=Hamara |first3=David K |last4=Williams |first4=Michael S |last5=Bode |first5=Rolfe C |last6=Fitzgibbon |first6=Michael R |last7=Ko |first7=Wenjeng |last8=Ward |first8=Michael G |last9=Sridhar |first9=K. R |last10=Blanchard |first10=Jeff A |last11=Lorenz |first11=Ralph D |last12=May |first12=Randy D |last13=Paige |first13=David A |last14=Pathare |first14=Asmin V |last15=Kring |first15=David A |last16=Leshin |first16=Laurie A |last17=Ming |first17=Douglas W |last18=Zent |first18=Aaron P |last19=Golden |first19=D. C |last20=Kerry |first20=Kristopher E |last21=Lauer |first21=H. Vern |last22=Quinn |first22=Richard C |bibcode=2001JGR...10617683B |doi-access=free }}

On May 29, 2008 (sol {{age in sols|2008|05|25|2008|05|29}}), electrical tests indicated an intermittent short circuit in TEGA,{{Cite press release |last1=Webster |first1=Guy |last2=Brown |first2=Dwayne |last3=Hammond |first3=Sara |date=May 30, 2008 |title=NASA'S Phoenix Lander Robotic Arm Camera Sees Possible Ice |url=https://www.jpl.nasa.gov/news/nasas-phoenix-lander-robotic-arm-camera-sees-possible-ice |url-status=live |archive-url=https://web.archive.org/web/20240110100557/https://www.jpl.nasa.gov/news/nasas-phoenix-lander-robotic-arm-camera-sees-possible-ice |archive-date=January 10, 2024 |access-date=May 30, 2008 |publisher=Jet Propulsion Laboratory |id=2008-090 }} resulting from a glitch in one of the two filaments responsible for ionizing volatiles.{{Cite news |last1=Thompson |first1=Andrea |date=May 30, 2008 |title=Mars lander hunts ice and hits a snag |url=https://www.nbcnews.com/id/wbna24896021 |url-status=live |archive-url=https://web.archive.org/web/20220128003342/https://www.nbcnews.com/id/wbna24896021 |archive-date=January 28, 2022 |access-date=May 19, 2020 |work=NBC News }} NASA worked around the problem by configuring the backup filament as the primary and vice versa.NASA press conference, June 2, 2008.

In early June, first attempts to get soil into TEGA were unsuccessful as it seemed too "cloddy" for the screens.{{Cite news |last=Thompson |first=Andrea |date=June 11, 2008 |title=Martian Soil Sample Clogs Phoenix Probe's Oven |url=https://www.space.com/5475-martian-soil-sample-clogs-phoenix-probe-oven.html |url-status=live |archive-url=https://web.archive.org/web/20231120025501/https://www.space.com/5475-martian-soil-sample-clogs-phoenix-probe-oven.html |archive-date=November 20, 2023 |access-date=February 12, 2023 |work=Space.com }}{{Cite news |last1=Thompson |first1=Andrea |date=June 11, 2008 |title=Clumpy Martian Soil Refuses to Budge |url=https://www.space.com/5482-clumpy-martian-soil-refuses-budge.html |url-status=live |archive-url=https://web.archive.org/web/20230607115858/https://www.space.com/5482-clumpy-martian-soil-refuses-budge.html |archive-date=June 7, 2023 |access-date=February 12, 2023 |work=Space.com }}

On June 11 the first of the eight ovens was filled with a soil sample after several tries to get the soil sample through the screen of TEGA.{{citation needed|date=July 2020}} On June 17, it was announced that no water was found in this sample; however, since it had been exposed to the atmosphere for several days prior to entering the oven, any initial water ice it might have contained could have been lost via sublimation.{{citation needed|date=January 2018}}

File:181445main mardi-hires.jpg

The Mars Descent Imager (MARDI) was intended to take pictures of the landing site during the last three minutes of descent. As originally planned, it would have begun taking pictures after the aeroshell departed, about {{cvt|8|km|mi}} above the Martian soil.{{citation needed|date=January 2018}}

Before launch, testing of the assembled spacecraft uncovered a potential data corruption problem with an interface card that was designed to route MARDI image data as well as data from various other parts of the spacecraft. The potential problem could occur if the interface card were to receive a MARDI picture during a critical phase of the spacecraft's final descent, at which point data from the spacecraft's Inertial Measurement Unit could have been lost; this data was critical to controlling the descent and landing. This was judged to be an unacceptable risk, and it was decided to not use MARDI during the mission.{{cite web|url=http://phoenix.lpl.arizona.edu/science_mardi.php|title=Mars Descent Imager (MARDI)|date=May 27, 2008|publisher=University of Arizona|access-date=February 9, 2016|archive-url=https://web.archive.org/web/20160221082421/http://phoenix.lpl.arizona.edu/science_mardi.php|archive-date=February 21, 2016|url-status=dead}} As the flaw was discovered too late for repairs, the camera remained installed on Phoenix but it was not used to take pictures, nor was its built-in microphone used.{{cite web|url=http://www.msss.com/msl/mardi/news/12Nov07/index.html|title=Mars Descent Imager (MARDI) Update|date=November 12, 2007|publisher=Malin Space Science Systems|access-date=December 3, 2007|archive-url=https://web.archive.org/web/20120904020224/http://www.msss.com/msl/mardi/news/12Nov07/index.html|archive-date=September 4, 2012|url-status=dead}}

MARDI images had been intended to help pinpoint exactly where the lander landed, and possibly help find potential science targets. It was also to be used to learn if the area where the lander lands is typical of the surrounding terrain. MARDI was built by Malin Space Science Systems.{{cite journal |doi=10.1029/1999JE001144 |title=Mars Descent Imager (MARDI) on the Mars Polar Lander |journal=Journal of Geophysical Research: Planets |volume=106 |issue=E8 |pages=17635–50 |year=2001 |last1=Malin |first1=M. C |last2=Caplinger |first2=M. A |last3=Carr |first3=M. H |last4=Squyres |first4=S |last5=Thomas |first5=P |last6=Veverka |first6=J |bibcode=2001JGR...10617635M |s2cid=62829221 |doi-access=free }} It would have used only 3 watts of power during the imaging process, less than most other space cameras. It had originally been designed and built to perform the same function on the Mars Surveyor 2001 Lander mission; after that mission was canceled, MARDI spent several years in storage until it was deployed on the Phoenix lander.

File:A prototype wet chemistry beaker.jpg showing some of the electrochemistry sensors on the sides of the beaker.]]

The Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) is an instrument package originally designed for the canceled Mars Surveyor 2001 Lander mission. It consists of a wet chemistry lab (WCL), optical and atomic force microscopes, and a thermal and electrical conductivity probe.{{Cite web |title=Spacecraft and Science Instruments |url=http://phoenix.lpl.arizona.edu/science05.php |url-status=dead |archive-url=https://web.archive.org/web/20070104223635/http://phoenix.lpl.arizona.edu/science05.php |archive-date=January 4, 2007 |access-date=March 10, 2007 |website=Phoenix Mars Lander }} The Jet Propulsion Laboratory built MECA. A Swiss consortium led by the University of Neuchatel contributed the atomic force microscope.{{cite web |url=http://www.mars-afm.ch/ |title=Atomic Force Microscope on Mars |access-date=May 25, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20080531151057/http://www.mars-afm.ch/ |archive-date=May 31, 2008 }}

Using MECA, researchers examined soil particles as small as 16 μm across; additionally, they attempted to determine the chemical composition of water-soluble ions in the soil. They also measured electrical and thermal conductivity of soil particles using a probe on the robotic arm scoop.{{cite web |url=http://www.decagon.com/thermal/info/mars.php |title=Decagon designs part of the Phoenix Mars Lander |access-date=May 25, 2008 |publisher=Decagon Devices, Inc. |url-status=dead |archive-url=https://web.archive.org/web/20080528153334/http://www.decagon.com/thermal/info/mars.php |archive-date=May 28, 2008 }}

This instrument presents 6 of 69 sample holders to an opening in the MECA instrument to which the robotic arm delivers the samples and then brings the samples to the optical microscope and the atomic force microscope.{{cite web|title=Transfer Engineering Devices Aboard Historic Phoenix Mars Mission|publisher=Nano Science and Technology Institute|url=http://www.nsti.org/press/PRshow.html?id=2185|access-date=June 15, 2008|archive-url=https://web.archive.org/web/20081230223910/http://www.nsti.org/press/PRshow.html?id=2185|archive-date=December 30, 2008|url-status=dead}} Imperial College London provided the microscope sample substrates.{{cite web |title=Imperial technology scanning for life on Mars |website=Science Business |url=http://bulletin.sciencebusiness.net/ebulletins/showissue.php3?page=/548/2463/8423 |access-date=May 26, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20080529005625/http://bulletin.sciencebusiness.net/ebulletins/showissue.php3?page=%2F548%2F2463%2F8423 |archive-date=May 29, 2008 }}

The optical microscope, designed by the University of Arizona, is capable of making images of the Martian regolith with a resolution of 256 pixels/mm or 16 micrometers/pixel. The field of view of the microscope is a {{cvt|2|×|2|mm|in}} sample holder to which the robotic arm delivers the sample. The sample is illuminated either by 9 red, green and blue LEDs or by 3 LEDs emitting ultraviolet light. The electronics for the readout of the CCD chip are shared with the robotic arm camera which has an identical CCD chip.

The atomic force microscope has access to a small area of the sample delivered to the optical microscope. The instrument scans over the sample with one of 8 silicon crystal tips and measures the repulsion of the tip from the sample. The maximum resolution is 0.1 micrometres. A Swiss consortium led by the University of Neuchatel contributed the atomic force microscope.

File:Phoenix wet chemistry lab.gif

The wet chemistry lab (WCL) sensor assembly and leaching solution were designed and built by Thermo Fisher Scientific.{{cite journal |pmid=11543343 |year=1999 |last1=West |first1=S. J |title=Electrochemistry on Mars |journal=American Laboratory |volume=31 |issue=20 |pages=48–54 |last2=Frant |first2=M. S |last3=Wen |first3=X |last4=Geis |first4=R |last5=Herdan |first5=J |last6=Gillette |first6=T |last7=Hecht |first7=M. H |last8=Schubert |first8=W |last9=Grannan |first9=S |last10=Kounaves |first10=S. P }} The WCL actuator assembly was designed and built by Starsys Research in Boulder, Colorado. Tufts University developed the reagent pellets, barium ISE, and ASV electrodes, and performed the preflight characterization of the sensor array.{{cite web|work=Tufts Journal|url=http://tuftsjournal.tufts.edu/archive/2007/september/corner/index.shtml|title=A decade of lab work hurtles toward Mars

|author1= Marjorie Howard|date= September 2007|access-date=May 29, 2008 }}

The robotic arm scooped up some soil and put it in one of four wet chemistry lab cells, where water was added, and, while stirring, an array of electrochemical sensors measured a dozen dissolved ions such as sodium, magnesium, calcium, and sulfate that leached out from the soil into the water. This provided information on the biological compatibility of the soil, both for possible indigenous microbes and for possible future Earth visitors.{{cite journal |doi=10.1029/2002JE001978 |pmid=14686320 |title=Mars Surveyor Program '01 Mars Environmental Compatibility Assessment wet chemistry lab: A sensor array for chemical analysis of the Martian soil |journal=Journal of Geophysical Research |volume=108 |issue=E7 |pages=13-1 - 13-12 |year=2003 |last1=Kounaves |first1=Samuel P |last2=Lukow |first2=Stefan R |last3=Comeau |first3=Brian P |last4=Hecht |first4=Michael H |last5=Grannan-Feldman |first5=Sabrina M |last6=Manatt |first6=Ken |last7=West |first7=Steven J |last8=Wen |first8=Xiaowen |last9=Frant |first9=Martin |last10=Gillette |first10=Tim |bibcode=2003JGRE..108.5077K |doi-access=free }}

All of the four wet chemistry labs were identical, each containing 26 chemical sensors and a temperature sensor. The polymer Ion Selective Electrodes (ISE) were able to determine the concentration of ions by measuring the change in electric potential across their ion-selective membranes as a function of concentration. Two gas sensing electrodes for oxygen and carbon dioxide worked on the same principle but with gas-permeable membranes. A gold micro-electrode array was used for the cyclic voltammetry and anodic stripping voltammetry. Cyclic voltammetry is a method to study ions by applying a waveform of varying potential and measuring the current–voltage curve. Anodic stripping voltammetry first deposits the metal ions onto the gold electrode with an applied potential. After the potential is reversed, the current is measured while the metals are stripped off the electrode.{{citation needed|date=January 2018}}

File:Phoenix thermal and electrical conductivity probe.jpg

The MECA contains a Thermal and Electrical Conductivity Probe (TECP). The TECP, designed by Decagon Devices, has four probes that made the following measurements: Martian soil temperature, relative humidity, thermal conductivity, electrical conductivity, dielectric permittivity, wind speed, and atmospheric temperature.

Three of the four probes have tiny heating elements and temperature sensors inside them. One probe uses internal heating elements to send out a pulse of heat, recording the time the pulse is sent and monitoring the rate at which the heat is dissipated away from the probe. Adjacent needles sense when the heat pulse arrives. The speed that the heat travels away from the probe as well as the speed that it travels between probes allows scientists to measure thermal conductivity, specific heat (the ability of the regolith to conduct heat relative to its ability to store heat) and thermal diffusivity (the speed at which a thermal disturbance is propagated in the soil).{{Cite journal |last=Zent |first=Aaron |date=July 30, 2008 |title=The Thermal Electrical Conductivity Probe (TECP) for Phoenix |url=https://ntrs.nasa.gov/api/citations/20090033138/downloads/20090033138.pdf#page=21 |url-status=live |journal=Journal of Geophysical Research: Planets |archive-url=https://web.archive.org/web/20230131130648/https://ntrs.nasa.gov/api/citations/20090033138/downloads/20090033138.pdf |archive-date=January 31, 2023 |access-date=April 30, 2018 |via=NASA Technical Reports Server }}

The probes also measured the dielectric permittivity and electrical conductivity, which can be used to calculate moisture and salinity of the regolith. Needles 1 and 2 work in conjunction to measure salts in the regolith, heat the soil to measure thermal properties (thermal conductivity, specific heat and thermal diffusivity) of the regolith, and measure soil temperature. Needles 3 and 4 measure liquid water in the regolith. Needle 4 is a reference thermometer for needles 1 and 2.

The TECP humidity sensor is a relative humidity sensor, so it must be coupled with a temperature sensor in order to measure absolute humidity. Both the relative humidity sensor and a temperature sensor are attached directly to the circuit board of the TECP and are, therefore, assumed to be at the same temperature.

The Meteorological Station (MET) recorded the daily weather of Mars during the course of the Phoenix mission. It is equipped with a wind indicator and pressure and temperature sensors. The MET also contains a lidar (light detection and ranging) device for sampling the number of dust particles in the air. It was designed in Canada by Optech and MDA, supported by the Canadian Space Agency. A team initially led by York University's Professor Diane Michelangeli{{Cite news |date=September 7, 2007 |title=Former lead scientist behind Canada's Mars weather station dies |url=https://www.cbc.ca/news/science/former-lead-scientist-behind-canada-s-mars-weather-station-dies-1.656658 |url-status=live |archive-url=https://web.archive.org/web/20210604062419/https://www.cbc.ca/news/science/former-lead-scientist-behind-canada-s-mars-weather-station-dies-1.656658 |archive-date=June 4, 2021 |access-date=May 29, 2020 }}{{Cite web|title=Phoenix Mars Mission - Mission - Teams - Diane Michelangeli|url=http://phoenix.lpl.arizona.edu/michelangeliDiane.php|website=phoenix.lpl.arizona.edu|access-date=2020-05-30|archive-date=May 8, 2020|archive-url=https://web.archive.org/web/20200508191527/http://phoenix.lpl.arizona.edu/michelangeliDiane.php|url-status=dead}} until her death in 2007, when Professor James Whiteway took over,{{Cite news|title=Canadians feel loss of Mars mission scientist|url=https://www.thestar.com/news/gta/2008/05/27/canadians_feel_loss_of_mars_mission_scientist.html|date=2008-05-27| author1= Sarah Barmak|newspaper=The Toronto Star|language=en|access-date=2020-05-30}} oversaw the science operations of the station. The York University team includes contributions from the University of Alberta, University of Aarhus (Denmark),{{cite web|title=The Telltale project |url=http://www.marslab.dk/TelltaleProject.html |publisher=marslab, Aarhus university, Denmark |access-date=May 27, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20080407164531/http://www.marslab.dk/TelltaleProject.html |archive-date=April 7, 2008 }} Dalhousie University,{{cite web|title=Mission: Mars|url=http://dalnews.dal.ca/2005/08/19/phoenix.html|access-date=December 28, 2007}} Finnish Meteorological Institute,{{cite web|title="Phoenix probe takes FMI's pressure sensor to Mars" | language= fi |url=http://www.fmi.fi/uutiset/index.html?A=1&Id=1185859119.html|access-date=August 6, 2007|archive-url=https://web.archive.org/web/20080412091649/http://www.fmi.fi/uutiset/index.html?A=1&Id=1185859119.html|archive-date=April 12, 2008|url-status=dead}} Optech, and the Geological Survey of Canada. Canadarm maker MacDonald Dettwiler and Associates (MDA) of Richmond, B.C. built the MET.{{cite news|title=Mars robot with Canadian component set for Saturday launch|work=Phoenix Mars Lander|url=https://www.cbc.ca/news/science/mars-robot-with-canadian-component-set-for-saturday-launch-1.640348|access-date=August 3, 2007 | date=August 3, 2007}}

File:181448main met-hires.jpg

File:Phoenix MET telltale Sol 2 cropped part gamma 4.01.png at a height of 2.3 m. This enhanced image shows wind from the northeast on Sol 3.]]

The surface wind velocity, pressure, and temperature were also monitored over the mission (from the tell-tale, pressure, and temperature sensors) and show the evolution of the atmosphere with time. To measure dust and ice contribution to the atmosphere, a lidar was employed. The lidar collected information about the time-dependent structure of the planetary boundary layer by investigating the vertical distribution of dust, ice, fog, and clouds in the local atmosphere.{{citation needed|date=January 2018}}

File:279902main Temperature SD.jpg

There are three temperature sensors (thermocouples) on a {{cvt|1|m|ft}} vertical mast (shown in its stowed position) at heights of approximately {{cvt|250|,|500|and|1000|mm|in}} above the lander deck. The sensors were referenced to a measurement of absolute temperature at the base of the mast. A pressure sensor built by Finnish Meteorological Institute is located in the Payload Electronics Box, which sits on the surface of the deck, and houses the acquisition electronics for the MET payload. The Pressure and Temperature sensors commenced operations on Sol 0 (May 26, 2008) and operated continuously, sampling once every 2 seconds.{{citation needed|date=January 2018}}

The Telltale is a joint Canadian/Danish instrument (right) which provides a coarse estimate of wind speed and direction. The speed is based on the amount of deflection from vertical that is observed, while the wind direction is provided by which way this deflection occurs. A mirror, located under the telltale, and a calibration "cross," above (as observed through the mirror) are employed to increase the accuracy of the measurement. Either camera, SSI or RAC, could make this measurement, though the former was typically used. Periodic observations both day and night aid in understanding the diurnal variability of wind at the Phoenix landing site.{{citation needed|date=January 2018}}

The wind speeds ranged from {{cvt|11|to|58|km/h|mph}}. The usual average speed was {{cvt|36|km/h|mph}}.

File:Lidar open.jpg

The vertical-pointing lidar was capable of detecting multiple types of backscattering (for example Rayleigh scattering and Mie Scattering), with the delay between laser pulse generation and the return of light scattered by atmospheric particles determining the altitude at which scattering occurs. Additional information was obtained from backscattered light at different wavelengths (colors), and the Phoenix system transmitted both 532 nm and 1064 nm. Such wavelength dependence may make it possible to discriminate between ice and dust, and serve as an indicator of the effective particle size.{{citation needed|date=January 2018}}

File:Sol 004 lidar.jpg

The Phoenix lidar's laser was a passive Q-switched Nd:YAG laser with the dual wavelengths of 1064 nm and 532 nm. It operated at 100 Hz with a pulse width of 10 ns. The scattered light was received by two detectors (green and IR) and the green signal was collected in both analog and photon counting modes.{{cite conference|title=LIDAR for Mars Atmospheric Studies on 2007 Scout Mission "Phoenix" |author=Carswell, Allan Ian |bibcode=2004ESASP.561..973C |volume=561 |date=2004 |page=973 |conference=22nd International Laser Radar Conference (ILRC 2004)|display-authors=etal|author-link=Allan Ian Carswell }}{{cite web|url=http://www.lpi.usra.edu/meetings/polar2006/pdf/8082.pdf|title=Phoenix LIDAR Characterization |author=Whiteway, J. |display-authors=4 |author2=Cook, C. |author3=Komguem, L. |author4=Ilnicki, M. |author5=Greene, M. |author6=Dickinson, C. |author7=Heymsfield, A.|date=2006|access-date=May 17, 2008}}

File:Phoenix Lidar Laser Movie.gif

The lidar was operated for the first time at noon on Sol 3 (May 29, 2008), recording the first surface extraterrestrial atmospheric profile. This first profile indicated well-mixed dust in the first few kilometers of the atmosphere of Mars, where the planetary boundary layer was observed by a marked decrease in scattering signal. The contour plot (right) shows the amount of dust as a function of time and altitude, with warmer colors (red, orange) indicating more dust, and cooler colors (blue, green), indicating less dust. There is also an instrumentation effect of the laser warming up, causing the appearance of dust increasing with time. A layer at {{cvt|3.5|km|mi}} can be observed in the plot, which could be extra dust, or—less likely, given the time of sol this was acquired—a low altitude ice cloud.{{citation needed|date=January 2018}}

The image on the left shows the lidar laser operating on the surface of Mars, as observed by the SSI looking straight up; the laser beam is the nearly-vertical line just right of center. Overhead dust can be seen both moving in the background, as well as passing through the laser beam in the form of bright sparkles.{{cite web |url=https://www.jpl.nasa.gov/spaceimages/details.php?id=PIA11030 |title=Zenith Movie showing Phoenix's Lidar Beam (Animation) |website=Jet Propulsion Laboratory |publisher=NASA |date=August 4, 2008 |access-date=August 28, 2018 }} The fact that the beam appears to terminate is the result of the extremely small angle at which the SSI is observing the laser—it sees farther up along the beam's path than there is dust to reflect the light back down to it.{{citation needed|date=January 2018}}

The laser device discovered snow falling from clouds; this was not known to occur before the mission.[http://www.jpl.nasa.gov/news/news.cfm?release=2009-106 NASA Phoenix Results Point to Martian Climate Cycles.] July 2, 2009 {{webarchive |url=https://web.archive.org/web/20090702223733/http://www.jpl.nasa.gov/news/news.cfm?release=2009-106 |date=July 2, 2009 }} It was also determined that cirrus clouds formed in the area.{{cite journal |doi=10.1126/science.1172344 |pmid=19574386 |title=Mars Water-Ice Clouds and Precipitation |journal=Science |volume=325 |issue=5936 |pages=68–70 |year=2009 |last1=Whiteway |first1=J. A |last2=Komguem |first2=L |last3=Dickinson |first3=C |last4=Cook |first4=C |last5=Illnicki |first5=M |last6=Seabrook |first6=J |last7=Popovici |first7=V |last8=Duck |first8=T. J |last9=Davy |first9=R |last10=Taylor |first10=P. A |last11=Pathak |first11=J |last12=Fisher |first12=D |last13=Carswell |first13=A. I |last14=Daly |first14=M |last15=Hipkin |first15=V |last16=Zent |first16=A. P |last17=Hecht |first17=M. H |last18=Wood |first18=S. E |last19=Tamppari |first19=L. K |last20=Renno |first20=N |last21=Moores |first21=J. E |last22=Lemmon |first22=M. T |last23=Daerden |first23=F |last24=Smith |first24=P. H |bibcode=2009Sci...325...68W |citeseerx=10.1.1.1032.6898 |s2cid=206519222 }}

File:Animation of Phoenix trajectory.gif}}{{·}}{{legend2| RoyalBlue |Earth}}{{·}}{{legend2| Lime |Mars}}]]

{{multiple image

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| caption1 = Phoenix is launched atop a Delta II 7925 rocket

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| caption2 = Noctilucent cloud created from the launch vehicle's exhaust gas.

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Phoenix was launched on August 4, 2007, at 5:26:34 a.m. EDT (09:26:34 UTC) on a Delta II 7925 launch vehicle from Pad 17-A of the Cape Canaveral Air Force Station. The launch was nominal with no significant anomalies. The Phoenix lander was placed on a trajectory of such precision that its first trajectory course correction burn, performed on August 10, 2007, at 7:30 a.m. EDT (11:30 UTC), was only 18 m/s. The launch took place during a launch window extending from August 3, 2007, to August 24, 2007. Due to the small launch window, the rescheduled launch of the Dawn mission (originally planned for July 7) had to be launched after Phoenix in September. The Delta II rocket was chosen due to its successful launch history, which includes launches of the Spirit and Opportunity Mars Exploration Rovers in 2003 and Mars Pathfinder in 1996.{{cite web|url=http://phoenix.lpl.arizona.edu/phases02.php|title=Phoenix Mars Mission – Launch|publisher=University of Arizona|archive-url=https://web.archive.org/web/20070208055806/http://phoenix.lpl.arizona.edu/phases02.php|archive-date= 8 February 2007|access-date=August 6, 2007}}

A noctilucent cloud was created by the exhaust gas from the Delta II 7925 rocket used to launch Phoenix.{{cite web|url=http://phoenix.lpl.arizona.edu/images.php?gID=187&cID=5|title=Phoenix Noctilucent Cloud|publisher=University of Arizona|access-date=August 4, 2007| archive-url=https://web.archive.org/web/20071103000228/http://phoenix.lpl.arizona.edu/images.php?gID=187&cID=5|archive-date= 3 November 2007}} The colors in the cloud formed from the prism-like effect of the ice particles present in the exhaust trail.

{{Clear}}

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{{Multiple image

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| image1 = Descent of Phoenix with a crater in the background taken by Mars Reconnaissance Orbiter.jpg

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| image2 = Phoenix Lander seen from MRO during EDL2.jpg

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| image3 = Mars Phoenix lander close 125.74922W 68.21883N.png

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| footer = Top: Mars Reconnaissance Orbiter (MRO) imaged Phoenix (lower left corner) in the line of sight to the 10-km-wide Heimdal Crater (the craft is actually 20 km from it). (left) MRO imaged Phoenix suspended from its parachute during descent through the Martian atmosphere. (right)

Bottom: Phoenix landing site near N. polar cap (left); MRO image of Phoenix on the surface of Mars. Also see [http://www.nasa.gov/mission_pages/phoenix/images/press/PSP_008591_2485_RGB_Lander_Inserts.html a larger image] showing the parachute / backshell, and heat shield. (right)

}}

The Jet Propulsion Laboratory made adjustments to the orbits of its two active satellites around Mars, Mars Reconnaissance Orbiter and Mars Odyssey, and the European Space Agency similarly adjusted the orbit of its Mars Express spacecraft to be in the right place on May 25, 2008, to observe Phoenix as it entered the atmosphere and then landed on the surface. This information helps designers to improve future landers.{{cite web|url=http://www.nasa.gov/mission_pages/phoenix/news/phoenix-20080228.html|title=Spacecraft at Mars Prepare to Welcome New Kid on the Block|access-date=May 25, 2008|archive-date=May 22, 2008|archive-url=https://web.archive.org/web/20080522154531/http://www.nasa.gov/mission_pages/phoenix/news/phoenix-20080228.html|url-status=dead}} The projected landing area was an ellipse {{cvt|100|by|20|km|mi}} covering terrain which has been informally named "Green Valley"{{cite web|url=http://www.nasa.gov/mission_pages/phoenix/news/phoenix-20080410.html|title=NASA Spacecraft Fine Tunes Course for Mars Landing|publisher=NASA|access-date=May 25, 2008|archive-date=May 15, 2008|archive-url=https://web.archive.org/web/20080515013244/http://www.nasa.gov/mission_pages/phoenix/news/phoenix-20080410.html|url-status=dead}} and contains the largest concentration of water ice outside the poles.

Phoenix entered the Martian atmosphere at nearly {{cvt|21,000|km/h|mph|abbr=on}}, and within 7 minutes had decreased its speed to {{cvt|8|km/h|mph}} before touching down on the surface. Confirmation of atmospheric entry was received at 4:46 p.m. PDT (23:46 UTC). Radio signals received at 4:53:44 p.m. PDT{{cite web|url=http://www.skyandtelescope.com/community/skyblog/newsblog/19252334.html|title=Phoenix: Redemption at Mars|publisher=SkyandTelescope.com|date=May 25, 2008|access-date=August 1, 2012| archive-url=https://web.archive.org/web/20131230232752/http://www.skyandtelescope.com/community/skyblog/newsblog/19252334.html| archive-date= 30 December 2013 | author1= Kelly Beatty| url-status= dead}} confirmed that Phoenix had survived its difficult descent and landed 15 minutes earlier, thus completing a 680 million km (422 million miles) flight from Earth.{{cite web|url=https://science.nasa.gov/headlines/y2008/25may_phoenix2.htm|title=Phoenix Lands on Mars!|date=May 25, 2008|publisher=NASA|url-status=dead|archive-url=https://web.archive.org/web/20090706055458/http://science.nasa.gov/headlines/y2008/25may_phoenix2.htm|archive-date=July 6, 2009}}

For unknown reasons, the parachute was deployed about 7 seconds later than expected, leading to a landing position some {{cvt|25|–|28|km|mi}} east, near the edge of the predicted 99% landing ellipse.

Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment (HiRISE) camera photographed Phoenix suspended from its parachute during its descent through the Martian atmosphere. This marked the first time ever one spacecraft photographed another in the act of landing on a planet{{cite web|url=http://www.nasa.gov/mission_pages/phoenix/images/press/9227-PHX_Lander.html|title=Phoenix Makes a Grand Entrance|date=May 26, 2008|publisher=NASA|access-date=May 27, 2008|archive-date=May 28, 2008|archive-url=https://web.archive.org/web/20080528034655/http://www.nasa.gov/mission_pages/phoenix/images/press/9227-PHX_Lander.html|url-status=dead}}{{cite news|url=http://www.jpl.nasa.gov/news/phoenix/images.php?fileID=9227|access-date=May 27, 2008|title=Phoenix Makes a Grand Entrance|publisher=NASA|archive-date=June 5, 2022|archive-url=https://web.archive.org/web/20220605122254/https://www.jpl.nasa.gov/news/phoenix/images.php?fileID=9227|url-status=dead}} (the Moon not being a planet, but a satellite). The same camera also imaged Phoenix on the surface with enough resolution to distinguish the lander and its two solar cell arrays. Ground controllers used Doppler tracking data from Odyssey and Mars Reconnaissance Orbiter to determine the lander's precise location as {{Coord|68.218830|N|234.250778|E|globe:Mars|display=inline,title}}.{{cite web|last=Lakdawalla|first=Emily|title=Phoenix Sol 2 press conference, in a nutshell|website=The Planetary Society weblog|publisher=Planetary Society|date=May 27, 2008|url=http://planetary.org/blog/article/00001470/|access-date=May 28, 2008|archive-date=April 22, 2014|archive-url=https://web.archive.org/web/20140422150353/http://www.planetary.org/blogs/emily-lakdawalla/2008/1470.html|url-status=dead}}The landing site is here [worldwind://goto/world=Mars&lat=68.21883&lon=234.250778&alt=1200000] on the NASA World Wind planetary viewer (free installation required)

Phoenix landed in the Green Valley of Vastitas Borealis on May 25, 2008,{{cite web|url=http://phoenix.lpl.arizona.edu/|title=Phoenix Mars Mission|url-status=dead|archive-url=https://web.archive.org/web/20080228000225/http://phoenix.lpl.arizona.edu/|archive-date=February 28, 2008}} in the late Martian northern hemisphere spring (L_s=76.73), where the Sun shone on its solar panels the whole Martian day.{{Cite web|title=NASA GISS: Mars24 Sunclock — Time on Mars|url=https://www.giss.nasa.gov/tools/mars24/|access-date=2023-02-12|website=www.giss.nasa.gov}} By the Martian northern Summer solstice (June 25, 2008), the Sun appeared at its maximum elevation of 47.0 degrees. Phoenix experienced its first sunset at the start of September 2008.

The landing was made on a flat surface, with the lander reporting only 0.3 degrees of tilt. Just before landing, the craft used its thrusters to orient its solar panels along an east–west axis to maximize power generation. The lander waited 15 minutes before opening its solar panels, to allow dust to settle. The first images from the lander became available around 7:00 p.m. PDT (2008-05-26 02:00 UTC).{{cite web|url=http://fawkes1.lpl.arizona.edu/gallery.php |title=Phoenix Mars Mission – Gallery |date=May 26, 2008 |publisher=Arizona University |url-status=dead |archive-url=https://web.archive.org/web/20110816020709/http://fawkes1.lpl.arizona.edu/gallery.php |archive-date=August 16, 2011 }} The images show a surface strewn with pebbles and incised with small troughs into polygons about {{cvt|5|m|ft}} across and {{cvt|10|cm|in}} high, with the expected absence of large rocks and hills.

Like the 1970s era Viking spacecraft, Phoenix used retrorockets for its final descent.{{cite web|url=https://www.newscientist.com/article/dn12421-phoenix-mars-lander-set-to-lift-off.html |title=Phoenix Mars lander set to lift off |publisher=New Scientist |access-date=August 4, 2007 |date=August 3, 2007 |url-status=dead |archive-url=https://web.archive.org/web/20070930014745/http://space.newscientist.com/article/dn12421-phoenix-mars-lander-set-to-lift-off.html |archive-date=September 30, 2007 }} Experiments conducted by Nilton Renno, mission co-investigator from the University of Michigan, and his students have investigated how much surface dust would be kicked up on landing.{{cite web|title=U-M scientists simulate the effects of blowing Mars dust on NASA's Phoenix lander, due for August launch|url=http://www.ns.umich.edu/htdocs/releases/story.php?id=5903|author=Jim Erickson|publisher=University of Michigan News Service|date=June 7, 2007}} Researchers at Tufts University, led by co-investigator Sam Kounaves, conducted additional in-depth experiments to identify the extent of the ammonia contamination from the hydrazine propellant and its possible effects on the chemistry experiments. In 2007, a report to the American Astronomical Society by Washington State University professor Dirk Schulze-Makuch, suggested that Mars might harbor peroxide-based life forms which the Viking landers failed to detect because of the unexpected chemistry.{{cite web|title=Did probes find Martian life ... or kill it off?|url=http://www.nbcnews.com/id/16516952|archive-url=https://web.archive.org/web/20131205002852/http://www.nbcnews.com/id/16516952/|url-status=dead|archive-date=December 5, 2013|author=Seth Borenstein|agency=Associated Press |work=NBC News|date=January 8, 2007|access-date=May 31, 2007}} The hypothesis was proposed long after any modifications to Phoenix could be made. One of the Phoenix mission investigators, NASA astrobiologist Chris McKay, stated that the report "piqued his interest" and that ways to test the hypothesis with Phoenix's instruments would be sought.

File:Phoenix mission horizon stitched high definition.jpg.]]

The robotic arm's first movement was delayed by one day when, on May 27, 2008, commands from Earth were not relayed to the Phoenix lander on Mars. The commands went to NASA's Mars Reconnaissance Orbiter as planned, but the orbiter's Electra UHF radio system for relaying commands to Phoenix temporarily shut off. Without new commands, the lander instead carried out a set of backup activities. On May 27 the Mars Reconnaissance Orbiter relayed images and other information from those activities back to Earth.

The robotic arm was a critical part of the Phoenix Mars mission. On May 28, scientists leading the mission sent commands to unstow its robotic arm and take more images of its landing site. The images revealed that the spacecraft landed where it had access to digging down a polygon across the trough and digging into its center.{{Cite web|title=Mission Involvement|url=https://www.lpl.arizona.edu/missions/phoenix05_28_pr.php|access-date=2023-02-12|website=Lunar and Planetary Laboratory & Department of Planetary Sciences | The University of Arizona|language=en|archive-date=February 12, 2023|archive-url=https://web.archive.org/web/20230212180444/https://www.lpl.arizona.edu/missions/phoenix05_28_pr.php|url-status=dead}}

The lander's robotic arm touched soil on Mars for the first time on May 31, 2008 (sol {{age in sols|2008|05|25|2008|05|31}}). It scooped dirt and started sampling the Martian soil for ice after days of testing its systems.{{cite web|author=James Wray |author2=Ulf Stabe |name-list-style=amp |url=http://www.thetechherald.com/article.php/200822/1121/Surface-ice-found-as-Phoenix-prepares-to-dig |title=thetechherald.com, Surface ice found as Phoenix prepares to dig |publisher=Thetechherald.com |access-date=July 13, 2012 |url-status=dead |archive-url=https://web.archive.org/web/20111003142810/http://www.thetechherald.com/article.php/200822/1121/Surface-ice-found-as-Phoenix-prepares-to-dig |archive-date=October 3, 2011 }}

{{See also|Geology of mars#Polar ice caps|l1=Martian polar ice caps|Water on Mars}}

The polygonal cracking at the landing zone had previously been observed from orbit, and is similar to patterns seen in permafrost areas in polar and high altitude regions of Earth.{{cite web|last=Harwood|first=William|title=Satellite orbiting Mars imaged descending Phoenix|website=Spaceflight Now|publisher=CBS News|date=May 26, 2008|url=http://spaceflightnow.com/mars/phoenix/080526mrochute.html|access-date=May 26, 2008}} Phoenix{{'}}s robotic arm camera took an image underneath the lander on sol 5 that shows patches of a smooth bright surface uncovered when thruster exhaust blew off overlying loose soil.{{cite web|last=Rayl |first=A. J. S. |title=Holy Cow, Snow Queen! Phoenix Landed on Ice Team Thinks |website=The Planetary Society |publisher=Planetary Society |date=June 1, 2008 |url=http://www.planetary.org/news/2008/0601_Holy_Cow_Snow_Queen_Phoenix_Landed_on.html |access-date=June 3, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20080605010056/http://www.planetary.org/news/2008/0601_Holy_Cow_Snow_Queen_Phoenix_Landed_on.html |archive-date=June 5, 2008 }} It was later shown to be water ice.{{cite journal|vauthors=Smith PH, Tamppari LK, Arvidson RE, Bass D, Blaney D, Boynton WV, Carswell A, Catling DC, Clark BC, Duck T, DeJong E |title=H2O at the Phoenix landing site |journal=Science |year=2009 |volume=325 |issue=5936 |pages=58–61 |doi=10.1126/science.1172339 |pmid=19574383 |bibcode=2009Sci...325...58S |s2cid=206519214 }}Mellon, M., et al. 2009. The periglacial landscape at the Phoenix landing site. Journal of Geophys. Res. 114. E00E07

On June 19, 2008 (sol {{age in sols|2008|05|25|2008|06|19}}), NASA announced that dice-sized clumps of bright material in the "Dodo-Goldilocks" trench dug by the robotic arm had vaporized over the course of four days, strongly implying that they were composed of water ice which sublimed following exposure. While dry ice also sublimes, under the conditions present it would do so at a rate much faster than observed.{{Cite web|title=NASA - Bright Chunks at Phoenix Lander's Mars Site Must Have Been Ice|url=https://www.nasa.gov/mission_pages/phoenix/news/phoenix-20080619.html|access-date=2023-02-12|website=www.nasa.gov|language=en|archive-date=September 24, 2017|archive-url=https://web.archive.org/web/20170924053119/https://www.nasa.gov/mission_pages/phoenix/news/phoenix-20080619.html|url-status=dead}}{{cite web|last=Rayl |first=A. J. S. |title=Phoenix Scientists Confirm Water-Ice on Mars |website=The Planetary Society |publisher=Planetary Society |date=June 21, 2008 |url=http://www.planetary.org/news/2008/0621_Phoenix_Scientists_Confirm_WaterIce_on.html |access-date=June 23, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20080627110632/http://www.planetary.org/news/2008/0621_Phoenix_Scientists_Confirm_WaterIce_on.html |archive-date=June 27, 2008 }}{{cite web |url=http://www.nasa.gov/mission_pages/phoenix/news/phoenix-20080620.html |title=Confirmation of Water on Mars |publisher=Nasa.gov |date=June 20, 2008 |access-date=July 13, 2012 |archive-date=July 1, 2008 |archive-url=https://web.archive.org/web/20080701104400/http://www.nasa.gov/mission_pages/phoenix/news/phoenix-20080620.html |url-status=dead }}

On July 31, 2008 (sol {{age in sols|2008|05|25|2008|07|31}}), NASA announced that Phoenix confirmed the presence of water ice on Mars, as predicted in 2002 by the Mars Odyssey orbiter. During the initial heating cycle of a new sample, TEGA's mass spectrometer detected water vapor when the sample temperature reached 0 °C.{{cite news|last=Johnson|first=John|title=There's water on Mars, NASA confirms|work=Los Angeles Times|date=August 1, 2008|url=http://www.latimes.com/news/science/la-sci-phoenix1-2008aug01,0,3012423.story|access-date=August 1, 2008}}

Liquid water cannot exist on the surface of Mars with its present low atmospheric pressure, except at the lowest elevations for short periods.{{cite journal |doi=10.1029/2004JE002261 |title=Formation of Martian gullies by the action of liquid water flowing under current Martian environmental conditions |journal=Journal of Geophysical Research |volume=110 |issue=E5 |pages=E05004 |year=2005 |last1=Heldmann |first1=Jennifer L |last2=Toon |first2=Owen B |last3=Pollard |first3=Wayne H |last4=Mellon |first4=Michael T |last5=Pitlick |first5=John |last6=McKay |first6=Christopher P |last7=Andersen |first7=Dale T |bibcode=2005JGRE..110.5004H |hdl=2060/20050169988 |s2cid=1578727 |hdl-access=free }}{{cite journal |doi=10.1029/2006GL025946 |title=Recent high-latitude icy mantle in the northern plains of Mars: Characteristics and ages of emplacement |journal=Geophysical Research Letters |volume=33 |issue=11 |pages=L11201 |year=2006 |last1=Kostama |first1=V.-P |last2=Kreslavsky |first2=M. A |last3=Head |first3=J. W |bibcode=2006GeoRL..3311201K |s2cid=17229252 |doi-access=free }}

With Phoenix in good working order, NASA announced operational funding through September 30, 2008 (sol {{age in sols|2008|05|25|2008|09|30}}). The science team worked to determine whether the water ice ever thaws enough to be available for life processes and if carbon-containing chemicals and other raw materials for life are present.

Additionally during 2008 and early 2009 a debate emerged within NASA over the presence of 'blobs' which appeared on photos of the vehicle's landing struts, which have been variously described as being either water droplets or 'clumps of frost'. Due to the lack of consensus within the Phoenix science project, the issue had not been raised in any NASA news conferences.{{Cite news|last=Chang|first=Kenneth|date=2009-03-17|title=Blobs in Photos of Mars Lander Stir a Debate: Are They Water?|language=en-US|work=The New York Times|url=https://www.nytimes.com/2009/03/17/science/17mars.html|access-date=2023-02-12|issn=0362-4331|url-access= subscription}}

One scientist thought that the lander's thrusters splashed a pocket of brine from just below the Martian surface onto the landing strut during the vehicle's landing. The salts would then have absorbed water vapor from the air, which would have explained how they appeared to grow in size during the first 44 sols (Martian days) before slowly evaporating as Mars temperature dropped.

Image:PIA10775 First trenches dug by Phoenix.jpg|The first two trenches dug by Phoenix in Martian soil. The trench on the right, informally called "Baby Bear", is the source of the [https://web.archive.org/web/20120318214753/http://www.planetary.org/news/2008/0612_Phoenix_Fledges_Science_Begins_on.html first samples delivered] to the onboard TEGA and the optical microscope for analysis.

Image:Ice sublimating in the Dodo-Goldilocks trench.gif|Clumps of bright material in the enlarged "Dodo-Goldilocks" trench vanished over the course of four days, implying that they were composed of ice which sublimated following exposure.

Image:Evaporating ice on Mars Phoenix lander image.jpg|Color versions of the photos showing ice sublimation, with the lower left corner of the trench enlarged in the insets in the upper right of the images.

On June 24, 2008 (sol {{age in sols|2008|05|25|2008|06|24}}), NASA's scientists launched a series of scientific tests. The robotic arm scooped up more soil and delivered it to 3 different on-board analyzers: an oven that baked it and tested the emitted gases, a microscopic imager, and a wet chemistry laboratory (WCL).{{cite web |url=http://www.computerworld.com.au/index.php/id;1266131885 |title=NASA: With Martian ice discovered, major tests beginning |publisher=Computerworld.com.au |date=June 24, 2008 |access-date=July 13, 2012 |url-status=dead |archive-url=https://web.archive.org/web/20081230220352/http://www.computerworld.com.au/index.php/id%3B1266131885 |archive-date=December 30, 2008 }} The lander's robotic arm scoop was positioned over the Wet Chemistry Lab delivery funnel on Sol 29 (the 29th Martian day after landing, i.e. June 24, 2008). The soil was transferred to the instrument on sol {{age in sols|2008|05|25|2008|06|25}} (June 25, 2008), and Phoenix performed the first wet chemistry tests. On Sol 31 (June 26, 2008) Phoenix returned the wet chemistry test results with information on the salts in the soil, and its acidity. The wet chemistry lab (WCL) was part of the suite of tools called the Microscopy, Electrochemistry and Conductivity Analyzer (MECA).{{cite web|url=http://uanews.org/node/20315 |archive-url=https://web.archive.org/web/20110514233638/http://uanews.org/node/20315 |url-status=usurped |archive-date=May 14, 2011 |title= Phoenix Lander Arm Poised to Deliver Sample for Wet Chemistry |publisher=Uanews.org |date=June 24, 2008 |access-date=July 13, 2012}}

Image:Phoenix mission landing.jpg|Phoenix footpad image, taken over 15 minutes after landing to ensure any dust stirred up had settled.

Image:Phoenix Sol1 pic3.jpg|One of the first surface images from Phoenix.

Image:PIA10741 Possible Ice Below Phoenix.jpg|View underneath lander towards south foot pad, showing patchy exposures of a bright surface, possibly ice.

{{Wide image|PIA13804-MarsPhoenixLander-Panorama-20080525b.jpg|800px|Panorama of rocks near the Phoenix Lander (May 25, 2008).}}

{{Wide image|PIA11044-PhoenixLander-WorkspaceNames-20080819.jpg|800px|Panorama of rocks near the Phoenix Lander (August 19, 2008).}}

A 360-degree panorama assembled from images taken on sols 1 and 3 after landing. The upper portion has been vertically stretched by a factor of 8 to bring out details. Visible near the horizon at full resolution are the backshell and parachute (a bright speck above the right edge of the left solar array, about {{cvt|300|m|ft}} distant) and the heat shield and its bounce mark (two end-to-end dark streaks above the center of the left solar array, about {{cvt|150|m|ft}} distant); on the horizon, left of the weather mast, is a crater.

File:PIA22223-Mars-PhoenixLander-Animation-20171221.gif |access-date=February 22, 2018 }}]]

The solar-powered lander operated two months longer than its three-month prime mission. The lander was designed to last 90 days, and had been running on bonus time since the successful end of its primary mission in August 2008.{{cite magazine |last=Madrigal |first=Alexis |title=Mars Phoenix Lander Runs Out of Juice |url=https://www.wired.com/wiredscience/2008/11/mars-phoenix-re/ |date=November 10, 2008 |magazine=Wired |access-date=February 26, 2014 }} On October 28, 2008 (sol {{age in sols|2008|05|25|2008|10|28}}), the lander went into safe mode due to power constraints based on the insufficient amount of sunlight reaching the lander,{{cite web |url=http://www.jpl.nasa.gov/news/news.cfm?release=2008-200 |title=NASA-JPL Phoenix mission status report – heater shutdowns |publisher=Jpl.nasa.gov |date=October 29, 2008 |access-date=July 13, 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120308184532/http://www.jpl.nasa.gov/news/news.cfm?release=2008-200 |archive-date=March 8, 2012 }} as expected at this time of year. It was decided then to shut down the four heaters that keep the equipment warm, and upon bringing the lander back from safe mode, commands were sent to turn off two of the heaters rather than only one as was originally planned for the first step. The heaters involved provide heat to the robotic arm, TEGA instrument and a pyrotechnic unit on the lander that were unused since landing, so these three instruments were also shut down.

On November 10, Phoenix Mission Control reported the loss of contact with the Phoenix lander; the last signal was received on November 2.{{cite tweet|user=MarsPhoenix|number=999393608 |title=Twitter Announcement From Phoenix Mission Ops |date=10 November 2008}} The demise of the craft occurred as a result of a dust storm that reduced power generation even further.{{cite web|last=Rayl |first=A.J.S. |title=Sun Sets on Phoenix, NASA Declares End of Mission |website=Planetary Society |publisher=Planetary Society |date=November 11, 2008 |url=http://www.planetary.org/news/2008/1111_Sun_Sets_on_Phoenix_NASA_Declares_End.html |access-date=November 11, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20081230212102/http://www.planetary.org/news/2008/1111_Sun_Sets_on_Phoenix_NASA_Declares_End.html |archive-date=December 30, 2008 }} While the spacecraft's work ended, the analysis of data from the instruments was in its earliest stages.

Though it was not designed to survive the frigid Martian winter, the spacecraft's safe mode kept the option open to reestablish communications if the lander could recharge its batteries during the next Martian spring. However, its landing location is in an area that is usually part of the north polar ice cap during the Martian winter, and the lander was seen from orbit to be encased in dry ice. It is estimated that, at its peak, the layer of CO₂ ice in the lander's vicinity would total about 30 grams/cm², which is enough to make a dense slab of dry ice at least {{cvt|7.5|in|cm|order=flip}} thick.{{cite news|first=Kelly|last=Beatty|title=Phoenix Amid the Winter Snow|date=November 9, 2009|publisher=Sky & Telescope Magazine|url=http://www.skyandtelescope.com/news/69627537.html|archive-url=https://archive.today/20130202090105/http://www.skyandtelescope.com/news/69627537.html|url-status=dead|archive-date=February 2, 2013|access-date=November 14, 2009}} It was considered unlikely that the spacecraft could endure these conditions, as its fragile solar panels would likely break off under so much weight.{{cite web|last=Lakdawalla|first=Emily|title=The end of Phoenix|website=The Planetary Society|publisher=Planetary Society|date=November 11, 2008|url=http://www.planetary.org/blog/article/00001735/|access-date=November 11, 2008|archive-date=March 18, 2012|archive-url=https://web.archive.org/web/20120318214835/http://www.planetary.org/blog/article/00001735/|url-status=dead}}

Scientists attempted to make contact with Phoenix starting January 18, 2010 (sol {{age in sols|2010|05|25|2008|01|18}}), but were unsuccessful. Further attempts in February and April also failed to pick up any signal from the lander.{{cite news|title=NASA to Check for Unlikely Winter Survival of Mars Lander |date=January 11, 2010 |publisher=Jet Propulsion Laboratory |url=http://www.jpl.nasa.gov/news/news.cfm?release=2010-008 |work=NASA |access-date=January 12, 2010 |url-status=dead |archive-url=https://web.archive.org/web/20100120070230/http://jpl.nasa.gov/news/news.cfm?release=2010-008 |archive-date=January 20, 2010 }}{{cite web |last1=Stephen |first1=Clark |title=Orbiter camera sees ice-covered Phoenix lander |url=http://www.spaceflightnow.com/news/n0911/04phoenix/ |website=spaceflightnow.com |publisher=Pole Star Publications |date=November 4, 2009 |access-date=May 19, 2020}}{{cite news|title=No Peep from Phoenix in Third Odyssey Listening Stint |date=April 13, 2010 |publisher=Jet Propulsion Laboratory |url=http://www.jpl.nasa.gov/news/news.cfm?release=2010-126 |work=NASA |access-date=May 6, 2010 |url-status=dead |archive-url=https://web.archive.org/web/20101103012114/http://www.jpl.nasa.gov/news/news.cfm?release=2010-126 |archive-date=November 3, 2010 }}[http://www.jpl.nasa.gov/news/news.cfm?release=2009-160 Frost-Covered Phoenix Lander Seen in Winter Images] (November 4, 2009) {{webarchive |url=https://web.archive.org/web/20091108044456/http://www.jpl.nasa.gov/news/news.cfm?release=2009-160 |date=November 8, 2009 }} Project manager Barry Goldstein announced on May 24, 2010, that the project was being formally ended. Images from the Mars Reconnaissance Orbiter showed that its solar panels were apparently irretrievably damaged by freezing during the Martian winter.{{cite news |last1=Maugh |first1=Thomas H. |title=Phoenix Mars Lander won't rise again |url=https://www.latimes.com/archives/la-xpm-2010-may-25-la-sci-mars-phoenix-20100525-story.html |access-date=May 19, 2020 |work=Los Angeles Times |date=May 25, 2010}}{{cite news|last=Goss|first=Heather|title=Hello Spacecraft? Are You Listening?|url=http://www.aviationweek.com/aw/blogs/space/index.jsp?plckController=Blog&plckScript=blogScript&plckElementId=blogDest&plckBlogPage=BlogViewPost&plckPostId=Blog:04ce340e-4b63-4d23-9695-d49ab661f385Post:533e9444-79a2-4787-b749-e0c33041941a|archive-url=https://web.archive.org/web/20110510020244/http://www.aviationweek.com/aw/blogs/space/index.jsp?plckController=Blog&plckScript=blogScript&plckElementId=blogDest&plckBlogPage=BlogViewPost&plckPostId=Blog%3A04ce340e-4b63-4d23-9695-d49ab661f385Post%3A533e9444-79a2-4787-b749-e0c33041941a|url-status=dead|archive-date=May 10, 2011|newspaper=AW&ST|date=May 25, 2010}}

Unlike some other places visited on Mars with landers (Viking and Pathfinder), nearly all the rocks near Phoenix are small. For about as far as the camera can see, the land is flat, but shaped into polygons between {{cvt|2|–|3|m|ft}} in diameter and are bounded by troughs that are {{cvt|20|to|50|cm|in}} deep. These shapes are due to ice in the soil expanding and contracting due to major temperature changes. The microscope showed that the soil on top of the polygons is composed of flat particles (probably a type of clay) and rounded particles. Also, unlike other places visited on Mars, the site has no ripples or dunes. Ice is present a few inches below the surface in the middle of the polygons, and along its edges, the ice is at least {{cvt|8|in|cm|order=flip}} deep. When the ice is exposed to the Martian atmosphere it slowly sublimates.{{cite web |last=Thompson |first=Andrea |title=The Dirt on Mars Lander Soil Findings |url=http://www.space.com/6918-dirt-mars-lander-soil-findings.html |date=July 2, 2009 |publisher=Space.com |access-date=October 22, 2012 }} Some dust devils were observed.

Snow was observed to fall from cirrus clouds. The clouds formed at a level in the atmosphere that was around {{cvt|−65|°C|°F}}, so the clouds would have to be composed of water-ice, rather than carbon dioxide-ice (dry ice) because, at the low pressure of the Martian atmosphere, the temperature for forming carbon dioxide ice is much lower—less than {{cvt|−120|°C|°F}}. It is now thought that water ice (snow) would have accumulated later in the year at this location.Witeway, J. et al. 2009. Mars Water-Ice Clouds and Precipitation. Science: 325. p68-70 This represents a milestone in understanding Martian weather. Wind speeds ranged from {{cvt|11|to|58|km/h|mph}}. The usual average speed was {{cvt|36|km/h|mph}}. These speeds seem high, but the atmosphere of Mars is very thin—less than 1% of the Earth's—and so did not exert much force on the spacecraft. The highest temperature measured during the mission was {{cvt|−19.6|°C|°F}}, while the coldest was {{cvt|−97.7|°C|°F}}.{{cite web |url=http://www.asc-csa.gc.ca/eng/media/news_releases/2009/0702.asp |title=Canadian Scientists Find Clues to the Water Cycle on Mars |access-date=December 19, 2010 |url-status=dead |archive-url=https://web.archive.org/web/20110705011110/http://www.asc-csa.gc.ca/eng/media/news_releases/2009/0702.asp |archive-date=July 5, 2011 }}

Interpretation of the data transmitted from the craft was published in the journal Science. As per the peer-reviewed data the presence of water ice has been confirmed and that the site had a wetter and warmer climate in the recent past. Finding calcium carbonate in the Martian soil leads scientists to think that the site had been wet or damp in the geological past. During seasonal or longer period diurnal cycles water may have been present as thin films. The tilt or obliquity of Mars changes far more than the Earth; hence times of higher humidity are probable.{{cite journal |doi=10.1126/science.1172768 |pmid=19574384 |title=Evidence for Calcium Carbonate at the Mars Phoenix Landing Site |journal=Science |volume=325 |issue=5936 |pages=61–4 |year=2009 |last1=Boynton |first1=W. V |last2=Ming |first2=D. W |last3=Kounaves |first3=S. P |last4=Young |first4=S. M. M |last5=Arvidson |first5=R. E |last6=Hecht |first6=M. H |last7=Hoffman |first7=J |last8=Niles |first8=P. B |last9=Hamara |first9=D. K |last10=Quinn |first10=R. C |last11=Smith |first11=P. H |last12=Sutter |first12=B |last13=Catling |first13=D. C |last14=Morris |first14=R. V |bibcode=2009Sci...325...61B |s2cid=26740165 }}

Chemistry results showed the surface soil to be moderately alkaline, with a pH of 7.7 ±0.5.{{cite journal |doi=10.1029/2009JE003424 |title=Wet Chemistry experiments on the 2007 Phoenix Mars Scout Lander mission: Data analysis and results |journal=Journal of Geophysical Research |volume=115 |issue=E7 |pages=E00E10 |year=2010 |last1=Kounaves |first1=S. P |last2=Hecht |first2=M. H |last3=Kapit |first3=J |last4=Gospodinova |first4=K |last5=Deflores |first5=L |last6=Quinn |first6=R. C |last7=Boynton |first7=W. V |last8=Clark |first8=B. C |last9=Catling |first9=D. C |last10=Hredzak |first10=P |last11=Ming |first11=D. W |last12=Moore |first12=Q |last13=Shusterman |first13=J |last14=Stroble |first14=S |last15=West |first15=S. J |last16=Young |first16=S. M. M |bibcode=2010JGRE..115.0E10K |doi-access= }}{{cite journal |doi=10.1029/2010GL042613 |title=Soluble sulfate in the martian soil at the Phoenix landing site |journal=Geophysical Research Letters |volume=37 |issue=9 |pages=L09201 |year=2010 |last1=Kounaves |first1=Samuel P |last2=Hecht |first2=Michael H |last3=Kapit |first3=Jason |last4=Quinn |first4=Richard C |last5=Catling |first5=David C |last6=Clark |first6=Benton C |last7=Ming |first7=Douglas W |last8=Gospodinova |first8=Kalina |last9=Hredzak |first9=Patricia |last10=McElhoney |first10=Kyle |last11=Shusterman |first11=Jennifer |bibcode=2010GeoRL..37.9201K |s2cid=12914422 }} The overall level of salinity is modest. TEGA analysis of its first soil sample indicated the presence of bound water and CO₂ that were released during the final (highest-temperature, 1,000 °C) heating cycle.{{cite web|last=Lakdawalla|first=Emily|title=Phoenix sol 30 update: Alkaline soil, not very salty, "nothing extreme" about it!|website=The Planetary Society|publisher=Planetary Society|date=June 26, 2008|url=http://www.planetary.org/blog/article/00001526/|access-date=June 26, 2008|archive-date=June 30, 2008|archive-url=https://web.archive.org/web/20080630074727/http://www.planetary.org/blog/article/00001526/|url-status=dead}}

The elements detected and measured in the samples are chloride, bicarbonate, magnesium, sodium, potassium, calcium, and sulfate. Further data analysis indicated that the soil contains soluble sulfate (SO₄^2-) at a minimum of 1.1% and provided a refined formulation of the soil.

Analysis of the Phoenix WCL also showed that the Ca(ClO₄)₂ in the soil has not interacted with liquid water of any form, perhaps for as long as 600 million years. If it had, the highly soluble Ca(ClO₄)₂ in contact with liquid water would have formed only CaSO₄. This suggests a severely arid environment, with minimal or no liquid water interaction.{{cite journal |doi=10.1016/j.icarus.2014.01.016 |title=Identification of the perchlorate parent salts at the Phoenix Mars landing site and possible implications |journal=Icarus |volume=232 |pages=226–31 |year=2014 |last1=Kounaves |first1=Samuel P |last2=Chaniotakis |first2=Nikos A |last3=Chevrier |first3=Vincent F |last4=Carrier |first4=Brandi L |last5=Folds |first5=Kaitlyn E |last6=Hansen |first6=Victoria M |last7=McElhoney |first7=Kyle M |last8=o'Neil |first8=Glen D |last9=Weber |first9=Andrew W |bibcode=2014Icar..232..226K }} The pH and salinity level were viewed as benign from the standpoint of biology.

;Perchlorate

On August 1, 2008, Aviation Week reported that "The White House has been alerted by NASA about plans to make an announcement soon on major new Phoenix lander discoveries concerning the "potential for life" on Mars, scientists tell Aviation Week & Space Technology."{{cite web|last=Covault|first=Craig|title=White House Briefed On Potential For Mars Life|publisher=Aviation Week|date=August 1, 2008|url=http://www.aviationweek.com/aw/generic/story_channel.jsp?channel=space&id=news/WH08018.xml&headline=White%20House%20Briefed%20On%20Potential%20For%20Mars%20Life|archive-url=https://web.archive.org/web/20110510020240/http://www.aviationweek.com/aw/generic/story_channel.jsp?channel=space&id=news%2FWH08018.xml&headline=White%20House%20Briefed%20On%20Potential%20For%20Mars%20Life|url-status=dead|archive-date=May 10, 2011|access-date=August 1, 2008}} This led to a subdued media speculation on whether some evidence of past or present life had been discovered.{{cite web|url=http://www.azonano.com/news.asp?newsID=7041|title=Speculation That The First Atomic Force Microscope on Mars Has Found Evidence of Life on Mars|date=August 4, 2008}}{{cite web|url=http://www.unmannedspaceflight.com/index.php?showtopic=5365&st=0|title=The MECA story, A place for speculation|date=July 21, 2008|publisher=unmannedspaceflight.com}}{{cite web|url=http://www.universetoday.com/2008/08/02/the-white-house-is-briefed-phoenix-about-to-announce-potential-for-life-on-mars/|title=The White House is Briefed: Phoenix About to Announce "Potential For Life" on Mars|date=August 2, 2008|publisher=Universe Today}} To quell the speculation, NASA released the preliminary findings stating that Mars soil contains perchlorate ({{chem|ClO|4}}) and thus may not be as life-friendly as thought earlier.{{cite news|url=http://www.latimes.com/news/printedition/asection/la-sci-phoenix6-2008aug06,0,4986721.story|title=Perchlorate found in Martian soil|date=August 6, 2008|work=Los Angeles Times|last=Johnson|first=John}}{{cite web|url=https://www.sciencedaily.com/releases/2008/08/080805192122.htm|publisher=Science Daily|date=August 6, 2008|title=Martian Life Or Not? NASA's Phoenix Team Analyzes Results}} The presence of almost 0.5% perchlorates in the soil was an unexpected finding with broad implications.{{cite journal |doi=10.1029/2008JE003084 |title=The MECA Wet Chemistry Laboratory on the 2007 Phoenix Mars Scout Lander |journal=Journal of Geophysical Research |volume=114 |issue=E3 |pages=E00A19 |year=2009 |last1=Kounaves |first1=Samuel P |last2=Hecht |first2=Michael H |last3=West |first3=Steven J |last4=Morookian |first4=John-Michael |last5=Young |first5=Suzanne M. M |last6=Quinn |first6=Richard |last7=Grunthaner |first7=Paula |last8=Wen |first8=Xiaowen |last9=Weilert |first9=Mark |last10=Cable |first10=Casey A |last11=Fisher |first11=Anita |last12=Gospodinova |first12=Kalina |last13=Kapit |first13=Jason |last14=Stroble |first14=Shannon |last15=Hsu |first15=Po-Chang |last16=Clark |first16=Benton C |last17=Ming |first17=Douglas W |last18=Smith |first18=Peter H |bibcode=2009JGRE..114.0A19K |doi-access=free }}

Laboratory research published in July 2017 demonstrated that when irradiated with a simulated Martian UV flux, perchlorates become bacteriocidal.{{cite journal| pmc=5500590 | pmid=28684729 | doi=10.1038/s41598-017-04910-3 | volume=7 | title=Perchlorates on Mars enhance the bacteriocidal effects of UV light | year=2017 | journal=Sci Rep | page=4662 | last1 = Wadsworth | first1 = J | last2 = Cockell | first2 = CS | issue=1 | bibcode=2017NatSR...7.4662W}} Two other compounds of the Martian surface, iron oxides and hydrogen peroxide, act in synergy with irradiated perchlorates to cause a 10.8-fold increase in cell death when compared to cells exposed to UV radiation after 60 seconds of exposure. It was also found that abraded silicates (quartz and basalt) lead to the formation of toxic reactive oxygen species.{{cite journal | last1 = Bak | first1 = Ebbe N. | last2 = Larsen | first2 = Michael G. | last3 = Moeller | first3 = Ralf | last4 = Nissen | first4 = Silas B. | last5 = Jensen | first5 = Lasse R. | last6 = Nørnberg | first6 = Per | last7 = Jensen | first7 = Svend J. K. | last8 = Finster | first8 = Kai | title=Silicates Eroded under Simulated Martian Conditions Effectively Kill Bacteria - A Challenge for Life on Mars | journal=Frontiers in Microbiology | date=September 12, 2017 | volume=8 |pages=1709 |doi=10.3389/fmicb.2017.01709 | pmid = 28955310 | pmc = 5601068 | doi-access = free }} The results leaves the question of the presence of organic compounds open-ended since heating the samples containing perchlorate would have broken down any organics present.{{cite web|title=NASA Phoenix Results Point to Martian Climate Cycles|publisher=NASA|date=July 2, 2009|url=http://www.nasa.gov/mission_pages/phoenix/news/phoenix-20090702.html|access-date=July 3, 2008|archive-date=July 4, 2009|archive-url=https://web.archive.org/web/20090704211909/http://www.nasa.gov/mission_pages/phoenix/news/phoenix-20090702.html|url-status=dead}} However, in the cold subsurface of Mars, which provides substantial protection against UV radiation, halotolerant organisms might survive enhanced perchlorate concentrations by physiological adaptations similar to those observed in the yeast Debaryomyces hansenii exposed in lab experiments to increasing NaClO₄ concentrations.{{Cite journal |last1=Heinz |first1=Jacob |last2=Doellinger |first2=Joerg |last3=Maus |first3=Deborah |last4=Schneider |first4=Andy |last5=Lasch |first5=Peter |last6=Grossart |first6=Hans-Peter |last7=Schulze-Makuch |first7=Dirk |date=2022-08-10 |title=Perchlorate-specific proteomic stress responses of Debaryomyces hansenii could enable microbial survival in Martian brines |journal=Environmental Microbiology |volume=24 |issue=11 |language=en |pages=1462–2920.16152 |doi=10.1111/1462-2920.16152 |pmid=35920032 |issn=1462-2912|doi-access=free |bibcode=2022EnvMi..24.5051H }}

Perchlorate (ClO₄) is a strong oxidizer, so it has the potential of being used for rocket fuel and as a source of oxygen for future missions.{{Cite web|url=http://blogs.discovermagazine.com/crux/2016/06/20/perchlorate-salt-mars-surface/#.WlTOTHnLghQ|title=Salts on Mars Are a Mixed Blessing|access-date=January 9, 2018|archive-date=January 10, 2018|archive-url=https://web.archive.org/web/20180110054434/http://blogs.discovermagazine.com/crux/2016/06/20/perchlorate-salt-mars-surface/#.WlTOTHnLghQ|url-status=dead}} Also, when mixed with water, perchlorate can greatly lower freezing point of water, in a manner similar to how salt is applied to roads to melt ice. So, perchlorate may be allowing small amounts of liquid water to form on the surface of Mars today. Gullies, which are common in certain areas of Mars, may have formed from perchlorate melting ice and causing water to erode soil on steep slopes.{{cite journal |doi=10.1126/science.1172466 |pmid=19574385 |title=Detection of Perchlorate and the Soluble Chemistry of Martian Soil at the Phoenix Lander Site |journal=Science |volume=325 |issue=5936 |pages=64–7 |year=2009 |last1=Hecht |first1=M. H |last2=Kounaves |first2=S. P |last3=Quinn |first3=R. C |last4=West |first4=S. J |last5=Young |first5=S. M. M |last6=Ming |first6=D. W |last7=Catling |first7=D. C |last8=Clark |first8=B. C |last9=Boynton |first9=W. V |last10=Hoffman |first10=J |last11=Deflores |first11=L. P |last12=Gospodinova |first12=K |last13=Kapit |first13=J |last14=Smith |first14=P. H |bibcode=2009Sci...325...64H |s2cid=24299495 }} Perchlorates have also been detected at the landing site of the Curiosity rover, nearer equatorial Mars, and in the martian meteorite EETA79001,{{cite journal |doi=10.1016/j.icarus.2013.11.012 |title=Evidence of martian perchlorate, chlorate, and nitrate in Mars meteorite EETA79001: Implications for oxidants and organics |journal=Icarus |volume=229 |pages=206–13 |year=2014 |last1=Kounaves |first1=Samuel P |last2=Carrier |first2=Brandi L |last3=O'Neil |first3=Glen D |last4=Stroble |first4=Shannon T |last5=Claire |first5=Mark W |bibcode=2014Icar..229..206K }} suggesting a "global distribution of these salts".{{cite news |last=Chang |first=Kenneth |title=Hitting Pay Dirt on Mars |url=https://www.nytimes.com/2013/10/01/science/space/hitting-pay-dirt-on-mars.html |date=October 1, 2013 |work=New York Times |access-date=October 2, 2013 }} Only highly refractory and/or well-protected organic compounds are likely to be preserved in the frozen subsurface. Therefore, the MOMA instrument planned to fly on the 2022 ExoMars rover will employ a method that is unaffected by the presence of perchlorates to detect and measure sub-surface organics.{{Cite web|title= Robotic Exploration of Mars - The ExoMars Rover Instrument Suite|url=http://exploration.esa.int/mars/45103-rover-instruments/?fbodylongid=2132|access-date=2023-02-12|website=exploration.esa.int|language=en-US}}

File:Phoenix mini-DVD on Mars.jpg

Attached to the deck of the lander (next to the US flag) is a special DVD compiled by The Planetary Society. The disc contains [https://www.planetary.org/outreach/visions-of-mars Visions of Mars], a multimedia collection of literature and art about the Red Planet. Works include the text of H.G. Wells' 1897 novel War of the Worlds (and the 1938 radio broadcast by Orson Welles), Percival Lowell's 1908 book Mars as the Abode of Life with a map of his proposed canals, Ray Bradbury's 1950 novel The Martian Chronicles, and Kim Stanley Robinson's 1993 novel Green Mars. There are also messages directly addressed to future Martian visitors or settlers from, among others, Carl Sagan and Arthur C. Clarke. In 2006, The Planetary Society collected a quarter of a million names submitted through the Internet and placed them on the disc, which claims, on the front, to be "the first library on Mars."{{cite web |title=Visions of Mars Project |url=https://www.planetary.org/outreach/visions-of-mars |website=The Planetary Society |access-date=2 December 2020 |language=en}} This DVD is made of a special silica glass designed to withstand the Martian environment, lasting for hundreds (if not thousands) of years on the surface while it awaits retrieval by future explorers. This is similar in concept to the Voyager Golden Record that was sent on the Voyager 1 and Voyager 2 missions.

The text just below the center of the disk reads:

{{blockquote|This archive, provided to the NASA Phoenix mission by The Planetary Society, contains literature and art (Visions of Mars), greetings from Mars visionaries of our day, and names of 21st century Earthlings who wanted to send their names to Mars. This DVD-ROM is designed to be read on personal computers in 2007. Information is stored in a spiral groove on the disc. A laser beam can scan the groove when metallized or a microscope can be used. Very small bumps and holes represent the zeroes and ones of digital information. The groove is about 0.74 micrometres wide. For more information refer to the standards document ECMA-268 (80 mm DVD Read-Only Disk).{{Cite web|title=Worldwide Me-the-Media Mars Scoop |website= Me the Media|url=https://www.methemedia.com/archives/13/|access-date=2023-02-12|language=en-US}}}}

A previous CD version was supposed to have been sent with the Russian spacecraft Mars 94, intended to land on Mars in Fall 1995.{{cite news |title=Sci-fi books go to Mars |url=https://da.tj.news/viewer?opub=Times_Transcript&date=19930626&page=51&search=John%20Marr&filename=0512_TT_A8630 |work=The Times-Transcript |agency=Reuters |date=June 26, 1993|url-access=subscription }}

{{reflist}}

{{Commons category|Phoenix mission}}

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;LPL, LMSS, JPL and NASA links

• [https://web.archive.org/web/20080228000225/http://phoenix.lpl.arizona.edu/ Phoenix mission lead home page]
• [https://web.archive.org/web/20111023024529/http://mars.jpl.nasa.gov/missions/present/phoenix.html Phoenix summary] at JPL
• [https://web.archive.org/web/20151019071127/http://solarsystem.nasa.gov/missions/profile.cfm?MCode=Phoenix Phoenix Profile] by [http://solarsystem.nasa.gov/ NASA's Solar System Exploration]
• [http://photojournal.jpl.nasa.gov/mission/Phoenix NASA's Phoenix Photojournal]
• [http://an.rsl.wustl.edu/phx NASA's Phoenix Analyst's Notebook] for accessing mission data and documents
• [http://www.nasa.gov/mission_pages/phoenix/images/raw/SSI/ssi_gallery_collection_archive_1.html NASA Archives of raw Phoenix mission images] {{Webarchive|url=https://web.archive.org/web/20080602060614/http://www.nasa.gov/mission_pages/phoenix/images/raw/SSI/ssi_gallery_collection_archive_1.html |date=June 2, 2008 }}, most recent first
• [https://www.youtube.com/watch?v=tR91HkTZ9VY NASA TV broadcast of Phoenix landing] (YouTube copy of NASA broadcast from 8 minutes before until 2 minutes after touchdown)
• [http://phoenix.lpl.arizona.edu/blogs.php Blogs of the scientists and engineers of the Phoenix team from launch through the end of the mission.] {{Webarchive|url=https://web.archive.org/web/20100728002532/http://phoenix.lpl.arizona.edu/blogs.php |date=July 28, 2010 }}

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;Other links

• [https://www.planetary.org/outreach/visions-of-mars-the-stories Complete List of Works on the Phoenix DVD]
• [https://www.planetary.org/outreach/introduction-to-visions-of-mars Written Introduction to the Visions of Mars Project]
• [https://web.archive.org/web/20160106143921/http://www.jumpcut.com/view/?id=E794095644A711DCBF54000423CF0184 Phoenix Mission Details Video]
• [https://archive.today/20080528165747/http://orionspace.net/mars/phoenix/22 may 2008-2.html Mars Express Support to Phoenix Landing] Includes animation of Phoenix descent and landing, plus KSC images of pre-flight processing and launch
• [https://web.archive.org/web/20120314230936/http://www.finda.com.au/story/2008/05/27/nasa-probe-sends-first-pictures-mars/ Article and news footage on the Phoenix landing]
• [https://web.archive.org/web/20120724075008/http://www.isset.ualberta.ca/what_we_do.html Canadian contribution at the University of Alberta]
• [https://gizmodo.com/5075490/nasas-phoenix-mars-lander-guest-blogging-on-giz Mars Phoenix Blog Page]
• [http://news.oreilly.com/2008/07/the-software-behind-the-mars-p.html Software Behind the Mars Phoenix Lander (Audio Interview)]
• [http://en.mars.bartal.org/?p=17 Color panorama of the landing site]
• [https://web.archive.org/web/20110629115003/http://video.google.com/videoplay?docid=1679027418837385215&hl=en Phoenix EDL Reconstruction 1B] – 9 minute video simulation based on actual EDL data
• [https://www.spacefoundation.org/2009/02/19/the-phoenix-mars-lander-team-wins-2009-jack-swigert-award-for-space-exploration/ Phoenix Mars Lander wins 2009 John L. "Jack" Swigert, Jr., Award for Space Achievement]
• [https://www.youtube.com/watch?v=1plIgTG9x-A Chris McKay: Results of the Phoenix Mission to Mars and Analog Sites on Earth]

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