Editing Astrobiology (section)

== Missions ==
Research into the environmental limits of life and the workings of extreme [[ecosystem]]s is ongoing, enabling researchers to better predict what planetary environments might be most likely to harbor life. Missions such as the [[Phoenix (spacecraft)|''Phoenix'' lander]], [[Mars Science Laboratory]], [[ExoMars]], [[Mars 2020]] rover to Mars, and the [[Cassini–Huygens|''Cassini'' probe]] to [[Saturn]]'s moons aim to further explore the possibilities of life on other planets in the Solar System.

;Viking program
{{main|Viking lander biological experiments}}
The two [[Viking program|Viking landers]] each carried four types of biological experiments to the surface of Mars in the late 1970s. These were the only Mars landers to carry out experiments looking specifically for [[metabolism]] by current microbial [[Life on Mars (planet)|life on Mars]]. The landers used a robotic arm to collect soil samples into sealed test containers on the craft. The two landers were identical, so the same tests were carried out at two places on Mars' surface; ''[[Viking 1]]'' near the equator and ''[[Viking 2]]'' further north.<ref name="Chambers">{{Cite book
 | first = Paul
 | last = Chambers
 | title = Life on Mars; The Complete Story
 | place = London
 | publisher = Blandford
 | date = 1999
 | isbn = 978-0-7137-2747-0
 | url-access = registration
 | url = https://archive.org/details/lifeonmarscomple00cham
 }}</ref> The result was inconclusive,<ref>Levin, G and P. Straaf. 1976. "Viking Labeled Release Biology Experiment: Interim Results". ''Science'': 194. 1322–1329.</ref> and is still disputed by some scientists.<ref name="Bianciardi-2012">{{cite journal|last1=Bianciardi |first1=Giorgio |last2=Miller |first2=Joseph D. |last3=Straat |first3=Patricia Ann |last4=Levin |first4=Gilbert V. |title=Complexity Analysis of the Viking Labeled Release Experiments |journal=IJASS |date=March 2012 |volume=13 |issue=1 |pages=14–26 |bibcode=2012IJASS..13...14B |doi=10.5139/IJASS.2012.13.1.14 |doi-access=free }}</ref><ref name="Discovery-20120412">{{cite web |last=Klotz |first=Irene |title=Mars Viking Robots 'Found Life' |url=http://news.discovery.com/space/mars-life-viking-landers-discovery-120412.html |date=12 April 2012 |publisher=[[Discovery Channel|Discovery News]] |access-date=16 April 2012 |archive-date=14 April 2012 |archive-url=https://web.archive.org/web/20120414195922/http://news.discovery.com/space/mars-life-viking-landers-discovery-120412.html |url-status=dead }}</ref><ref name="Navarro">{{Cite journal|last1=Navarro-González| first1=R.| date=2006| title=The limitations on organic detection in Mars-like soils by thermal volatilization–gas chromatography – MS and their implications for the Viking results| journal=[[PNAS]]| volume=103| issue=44| pages=16089–16094| doi=10.1073/pnas.0604210103| pmid=17060639 |pmc=1621051| bibcode = 2006PNAS..10316089N| display-authors=1| last2=Navarro| first2=K. F.|last3=Rosa |first3=J. d. l.| last4=Iniguez| first4=E.| last5=Molina| first5=P.| last6=Miranda| first6=L. D.|last7=Morales| first7=P.| last8=Cienfuegos| first8=E.| last9=Coll| first9=P. | doi-access=free}}</ref><ref name="Paepe">{{Cite journal| title=The Red Soil on Mars as a proof for water and vegetation| journal=Geophysical Research Abstracts| date=2007| first=Ronald| last=Paepe| volume=9| issue=1794| url=http://www.cosis.net/abstracts/EGU2007/01794/EGU2007-J-01794.pdf?PHPSESSID=e| format=PDP| access-date=2 May 2012| archive-url=https://web.archive.org/web/20110613164620/http://www.cosis.net/abstracts/EGU2007/01794/EGU2007-J-01794.pdf?PHPSESSID=e| archive-date=13 June 2011| url-status=dead}}</ref>
 
[[Norman Horowitz]] was the chief of the [[Jet Propulsion Laboratory]] bioscience section for the [[Mariner program|Mariner]] and [[Viking program|Viking]] missions from 1965 to 1976.  Horowitz considered that the great versatility of the carbon atom makes it the element most likely to provide solutions, even exotic solutions, to the problems of survival of life on other planets.<ref name = Horowitz1986>Horowitz, N.H. (1986). Utopia and Back and the search for life in the solar system. New York: W.H. Freeman and Company. {{ISBN|0-7167-1766-2}}</ref>  However, he also considered that the conditions found on Mars were incompatible with carbon based life.

;''Beagle 2''
[[Image:Beagle 2 replica.jpg|thumb|Replica of the 33.2&nbsp;kg ''Beagle-2'' lander]]
[[File:Msl20110519 PIA14156-full.jpg|thumb|[[Mars Science Laboratory]] rover concept artwork]]
''[[Beagle 2]]'' was an unsuccessful [[United Kingdom|British]] Mars lander that formed part of the [[European Space Agency]]'s 2003 [[Mars Express]] mission. Its primary purpose was to search for signs of [[life on Mars]], past or present. Although it landed safely, it was unable to correctly deploy its solar panels and telecom antenna.<ref>{{cite web|url=http://beagle2.open.ac.uk/index.htm|title=Beagle 2 : the British led exploration of Mars|access-date=13 March 2015|archive-url=https://web.archive.org/web/20160304034552/http://beagle2.open.ac.uk/index.htm|archive-date=4 March 2016|url-status=dead}}</ref>

;EXPOSE
[[EXPOSE]] is a multi-user facility mounted in 2008 outside the [[International Space Station]] dedicated to astrobiology.<ref name="Rabbow">{{cite journal|title=Expose, an Astrobiological Exposure Facility on the International Space Station – from Proposal to Flight |journal=Orig Life Evol Biosph |date=9 July 2009 |author1=Elke Rabbow |author2=Gerda Horneck |author3=Petra Rettberg |author4=Jobst-Ulrich Schott |author5=Corinna Panitz |author6=Andrea L'Afflitto |author7=Ralf von Heise-Rotenburg |author8=Reiner Willnecker |author9=Pietro Baglioni |author10=Jason Hatton |author11=Jan Dettmann |author12=René Demets |author13=Günther Reitz |doi=10.1007/s11084-009-9173-6 |url=http://www.prism.gatech.edu/~alafflitto3/Documents/Rabbow_Horneck_LAfflitto_Origin_of_Life_and_Evolution_of_Biosphere.pdf |access-date=8 July 2013 |bibcode=2009OLEB...39..581R |pmid=19629743 |volume=39 |issue=6 |pages=581–598 |s2cid=19749414 |url-status=dead |archive-url=https://web.archive.org/web/20140110151139/http://www.prism.gatech.edu/~alafflitto3/Documents/Rabbow_Horneck_LAfflitto_Origin_of_Life_and_Evolution_of_Biosphere.pdf |archive-date=10 January 2014 }}</ref><ref name="Experimental methods">{{cite journal | title = Experimental methods for studying microbial survival in extraterrestrial environments | journal = Journal of Microbiological Methods | date = 23 October 2009 | author1 = Karen Olsson-Francis | author2 = Charles S. Cockell | volume = 80 | pages = 1–13 | url = http://www1.univap.br/~spilling/AB/Olsson-francis_cockel_2010_astrobiology_Exp.pdf | access-date = 31 July 2013 | doi = 10.1016/j.mimet.2009.10.004 | pmid = 19854226 | issue = 1 | archive-url = https://web.archive.org/web/20130918161906/http://www1.univap.br/~spilling/AB/Olsson-francis_cockel_2010_astrobiology_Exp.pdf | archive-date = 18 September 2013 | url-status = dead | df = dmy-all }}</ref> EXPOSE was developed by the [[European Space Agency]] (ESA) for [[Spaceflight|long-term spaceflights]] that allow exposure of [[organic chemical]]s and biological samples to [[outer space]] in [[low Earth orbit]].<ref name="home">{{cite web | url = http://smsc.cnes.fr/EXPOSE/ | title = Expose – home page | access-date = 8 July 2013 | publisher = Centre national d'études spatiales (CNES) | archive-url = https://web.archive.org/web/20130115000920/http://smsc.cnes.fr/EXPOSE/ | archive-date = 15 January 2013 | url-status = dead | df = dmy-all }}</ref>

;Mars Science Laboratory
The [[Mars Science Laboratory]] (MSL) mission landed the [[Curiosity (rover)|''Curiosity'']] [[Rover (space exploration)|rover]] that is currently in operation on [[Mars]].<ref name="MSLNameWebsite">{{cite web |title=Name NASA's Next Mars Rover |url=http://marsrovername.jpl.nasa.gov/ |publisher=NASA/JPL |date=27 May 2009 |access-date=27 May 2009 |archive-url=https://web.archive.org/web/20090522004939/http://marsrovername.jpl.nasa.gov/ |archive-date=22 May 2009 |url-status=dead }}</ref> It was launched 26 November 2011, and landed at [[Gale (crater)|Gale Crater]] on 6 August 2012. Mission objectives are to help assess Mars' [[Planetary habitability|habitability]] and in doing so, determine whether Mars is or has ever been able to support [[Life on Mars (planet)|life]],<ref name="MSL-main_page">{{cite web |title=Mars Science Laboratory: Mission  |url=http://marsprogram.jpl.nasa.gov/msl/mission/|archive-url=https://web.archive.org/web/20060305231951/http://marsprogram.jpl.nasa.gov/msl/mission/|url-status=dead|archive-date=5 March 2006| publisher=NASA/JPL | access-date=12 March 2010 }}</ref> collect data for a future [[Human mission to Mars|human mission]], study Martian geology, its climate, and further assess the role that [[Water on Mars|water]], an essential ingredient for life as we know it, played in forming minerals on Mars.

;''Tanpopo''
The [[Tanpopo (mission)|''Tanpopo'']] mission is an orbital astrobiology experiment investigating the potential interplanetary transfer of life, [[organic compound]]s, and possible terrestrial particles in the low Earth orbit. The purpose is to assess the [[panspermia]] hypothesis and the possibility of natural interplanetary transport of microbial life as well as prebiotic organic compounds. Early mission results show evidence that some clumps of microorganism can survive for at least one year in space.<ref name='AGU2017'>[http://blogs.agu.org/geospace/2017/05/19/early-tanpopo-mission-results-show-microbes-can-survive-space/ "Early Tanpopo mission results show microbes can survive in space"]. American Geophysical Union. ''Geospace''. Larry O'Hanlon. 19 May 2017.</ref> This may support the idea that clumps greater than 0.5 millimeters of microorganisms could be one way for life to spread from planet to planet.<ref name='AGU2017'/>

;''ExoMars'' rover
[[File:ExoMars model at ILA 2006.jpg|thumb|ExoMars rover model]]
''[[ExoMars]]'' is a robotic mission to Mars to search for possible [[biosignature]]s of [[Life on Mars|Martian life]], past or present. This astrobiological mission was under development by the [[European Space Agency]] (ESA) in partnership with the [[Russian Federal Space Agency]] (Roscosmos); it was planned for a 2022 launch;<ref name="still keen">{{cite news |last=Amos |first=Jonathan | title = Europe still keen on Mars missions | date = 15 March 2012 | url = https://www.bbc.co.uk/news/science-environment-17390576 | work = BBC News | access-date = 16 March 2012}}</ref><ref name="Svitak">{{cite news | last = Svitak | first = Amy | title = Europe Joins Russia on Robotic ExoMars | date = 16 March 2012 | url = http://www.aviationweek.com/aw/generic/story_channel.jsp?channel=space&id=news/awx/2012/03/15/awx_03_15_2012_p0-437120.xml&headline=Europe%20Joins%20Russia%20on%20Robotic%20ExoMars | work = Aviation Week | access-date = 16 March 2012 }}{{Dead link|date=September 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref><ref name="Selding">{{cite news |last=Selding |first=Peter B. de | title = ESA Ruling Council OKs ExoMars Funding | date = 15 March 2012 | url = http://www.spacenews.com/civil/120315-esa-council-oks-exomars.html | archive-url = https://archive.today/20121206010858/http://www.spacenews.com/civil/120315-esa-council-oks-exomars.html | url-status = dead | archive-date = 6 December 2012 | work = Space News | access-date = 16 March 2012}}</ref> however, technical and funding issues and the [[Russian invasion of Ukraine]] have forced ESA to repeatedly delay the rover's delivery to 2028.<ref name=":0">{{Cite web |last=Foust |first=Jeff |date=2024-04-10 |title=ESA awards contract to Thales Alenia Space to restart ExoMars |url=https://spacenews.com/esa-awards-contract-to-thales-alenia-space-to-restart-exomars/ |access-date=2024-04-11 |website=SpaceNews |language=en-US}}</ref>

;Mars 2020
[[File:PIA23962-Mars2020-Rover&Helicopter-20200714.jpg|thumb|Artist's rendition of the [[Perseverance (rover)|''Perseverance'' rover]] on Mars, with the mini-helicopter [[Mars Helicopter Ingenuity|''Ingenuity'']] in front]]
[[Mars 2020]] successfully landed its rover ''[[Perseverance (rover)|Perseverance]]'' in [[Jezero Crater]] on 18 February 2021. It will investigate environments on Mars relevant to astrobiology, investigate its surface [[Geology of Mars|geological processes]] and history, including the assessment of its past [[Planetary habitability|habitability]] and potential for preservation of [[biosignature]]s and [[biomolecule]]s within accessible geological materials.<ref name="Cowing">{{cite web | url = http://spaceref.com/mars/science-definition-team-for-the-2020-mars-rover.html | archive-url = https://archive.today/20130203233556/http://spaceref.com/mars/science-definition-team-for-the-2020-mars-rover.html | url-status = dead | archive-date = 3 February 2013 | title = Science Definition Team for the 2020 Mars Rover | access-date = 21 December 2012 | last = Cowing | first = Keith | date = 21 December 2012 | work = NASA | publisher = Science Ref }}</ref> The Science Definition Team is proposing the rover collect and package at least 31 samples of rock cores and soil for a later mission to bring back for more definitive analysis in laboratories on Earth. The rover could make measurements and technology demonstrations to help designers of a [[Human mission to Mars|human expedition]] understand any hazards posed by Martian dust and demonstrate how to collect [[carbon dioxide]] (CO<sub>2</sub>), which could be a resource for making molecular oxygen (O<sub>2</sub>) and [[rocket fuel]].<ref name="goals">{{cite news | title = Science Team Outlines Goals for NASA's 2020 Mars Rover | date = 9 July 2013 | publisher = NASA | url = http://www.jpl.nasa.gov/news/news.php?release=2013-217 | work = Jet Propulsion Laboratory | access-date = 10 July 2013 }}</ref><ref name="FAQ">{{cite web | url = http://mars.nasa.gov/files/m2020/Mars2020FAQs.pdf | title = Mars 2020 Science Definition Team Report – Frequently Asked Questions | access-date = 10 July 2013 | date = 9 July 2013 | work = NASA}}</ref>

;''Europa Clipper''
''[[Europa Clipper]]'' is a mission launched by NASA on 14 October 2024 that will conduct detailed reconnaissance of [[Jupiter]]'s moon [[Europa (moon)|Europa]] beginning in 2030, and will investigate whether its internal ocean could harbor conditions suitable for life.<ref>{{Cite web |date=October 14, 2024 |title=NASA's Europa Clipper launches aboard SpaceX rocket, bound for Jupiter's icy ocean moon |url=https://www.latimes.com/science/story/2024-10-14/nasa-jupiter-probe-launches-aboard-spacex-rocket |access-date=October 14, 2024 |website=Los Angeles Times}}</ref><ref name="missions">{{cite news | title = Europa Clipper | date = November 2013 | publisher = NASA | url = http://solarsystem.nasa.gov/missions/profile.cfm?MCode=EuropaClipper&Display=ReadMore | work = Jet Propulsion Laboratory | access-date = 13 December 2013 | archive-url = https://web.archive.org/web/20131213193916/http://solarsystem.nasa.gov/missions/profile.cfm?MCode=EuropaClipper&Display=ReadMore | archive-date = 13 December 2013 | url-status = dead | df = dmy-all }}</ref><ref name="FPE">{{cite news | first = Van | last = Kane | title = Europa Clipper Update | date = 26 May 2013 | url = http://futureplanets.blogspot.com/2013/05/europa-clipper-update.html | work = Future Planetary Exploration | access-date = 13 December 2013}}</ref> It will also aid in the selection of future [[Lander (spacecraft)|landing sites]].<ref name="Europa Lander 2013">{{cite journal | title = Science Potential from a Europa Lander | journal = Astrobiology | date = 2013 | first1 = Robert T. | last1 = Pappalardo |author2= S. Vance |author3=F. Bagenal |author4=B.G. Bills |author5=D.L. Blaney |author5-link= Diana Blaney |author6=D.D. Blankenship |author7=W.B. Brinckerhoff | volume = 13 | issue = 8| doi=10.1089/ast.2013.1003 | bibcode=2013AsBio..13..740P | pages=740–773 | pmid=23924246|display-authors=etal| hdl = 1721.1/81431 | s2cid = 10522270 | url=https://dspace.mit.edu/bitstream/1721.1/81431/2/Pappalardo_Science-potential.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://dspace.mit.edu/bitstream/1721.1/81431/2/Pappalardo_Science-potential.pdf |archive-date=2022-10-09 |url-status=live | hdl-access=free }}</ref><ref>{{citation | first = D. | last = Senske | contribution = Europa Mission Concept Study Update | title = Presentation to Planetary Science Subcommittee | date = 2 October 2012| url = http://www.lpi.usra.edu/pss/oct2012/presentations/5_Senske_Europa.pdf | access-date = 14 December 2013}}</ref>

;''Dragonfly''
''[[Dragonfly (Titan space probe)|Dragonfly]]'' is a NASA mission scheduled to land on [[Titan (moon)|Titan]] in 2036 to assess its microbial habitability and study its prebiotic chemistry. ''Dragonfly'' is a [[rotorcraft]] lander that will perform controlled flights between multiple locations on the surface, which allows sampling of diverse regions and geological contexts.<ref name='APL draft'>[http://dragonfly.jhuapl.edu/News-and-Resources/docs/34_03-Lorenz.pdf Dragonfly: A Rotorcraft Lander Concept for Scientific Exploration at Titan] Ralph D. Lorenz, Elizabeth P. Turtle, Jason W. Barnes, Melissa G. Trainer, Douglas S. Adams, Kenneth E. Hibbard, Colin Z. Sheldon, Kris Zacny, Patrick N. Peplowski, David J. Lawrence, Michael A. Ravine, Timothy G. McGee, Kristin S. Sotzen, Shannon M. MacKenzie, Jack W. Langelaan, Sven Schmitz, Larry S. Wolfarth, and Peter D. Bedini. 2018. Johns Hopkins APL Technical Digest, 34(3), 374-387</ref>

===Proposed concepts===

;''Icebreaker Life''
''[[Icebreaker Life]]'' is a lander mission that was proposed for NASA's [[Discovery Program]] for the 2021 launch opportunity,<ref name='Icebreaker2021'>{{cite journal | title = The ''Icebreaker Life'' Mission to Mars: A Search for Biomolecular Evidence for Life | journal = Astrobiology | date = 5 April 2013 | author1=Christopher P. McKay | author2=Carol R. Stoker | author3=Brian J. Glass | author4=Arwen I. Davé | author5=Alfonso F. Davila | author6=Jennifer L. Heldmann | author7=Margarita M. Marinova | author8=Alberto G. Fairen | author9=Richard C. Quinn | author10=Kris A. Zacny | author11=Gale Paulsen | author12=Peter H. Smith | author13=Victor Parro | author14=Dale T. Andersen | author15=Michael H. Hecht | author16=Denis Lacelle | author17=Wayne H. Pollard | display-authors = 6 | volume = 13 | issue = 4 | pages = 334–353 | doi = 10.1089/ast.2012.0878 | pmid = 23560417 |bibcode = 2013AsBio..13..334M}}</ref> but it was not selected for development. It would have had a stationary lander that would be a near copy of the successful 2008 [[Phoenix (spacecraft)|''Phoenix'']] and it would have carried an upgraded astrobiology scientific payload, including a 1-meter-long core drill to sample ice-cemented ground in the northern plains to conduct a search for [[organic molecule]]s and evidence of current or past [[life on Mars]].<ref name="AstrobioMag">{{cite news |last=Choi |first=Charles Q. | title = Icebreaker Life Mission | date = 16 May 2013 | url = http://www.astrobio.net/exclusive/5476/mars-icebreaker-life-mission | work = [[Astrobiology Magazine]] | access-date = 1 July 2013 |archive-url=https://web.archive.org/web/20151009000704/http://www.astrobio.net/news-exclusive/mars-icebreaker-life-mission/ |archive-date=2015-10-09 |url-status=usurped}}</ref><ref name="LPI 2012">{{cite book | author1 = C. P. McKay |author2= Carol R. Stoker |author3=Brian J. Glass |author4=Arwen I. Davé |author5=Alfonso F. Davila |author6=Jennifer L. Heldmann |author7=Margarita M. Marinova |author8=Alberto G. Fairen |author9=Richard C. Quinn |author10=Kris A. Zacny |author11=Gale Paulsen |author12=Peter H. Smith |author13=Victor Parro |author14=Dale T. Andersen |author15=Michael H. Hecht |author16=Denis Lacelle |author17=Wayne H. Pollard | display-authors = 6 | contribution = The Icebreaker Life Mission to Mars: A Search for Biochemical Evidence for Life | title = Concepts and Approaches for Mars Exploration | publisher = Lunar and Planetary Institute | date = 2012 | url = http://www.lpi.usra.edu/meetings/marsconcepts2012/pdf/4091.pdf | access-date = 1 July 2013}}</ref> One of the key goals of the ''Icebreaker Life'' mission is to test the [[hypothesis]] that the ice-rich ground in the polar regions has significant concentrations of organics due to protection by the ice from [[Oxidizing agent|oxidants]] and [[Sunlight|radiation]].

;''Journey to Enceladus and Titan''
''[[Journey to Enceladus and Titan]]'' (''JET'') is an astrobiology mission concept to assess the [[planetary habitability|habitability]] potential of [[Saturn]]'s moons [[Enceladus]] and [[Titan (moon)|Titan]] by means of an orbiter.<ref name="Sotin2011">{{cite conference |last1=Sotin |first1=C. |last2=Altwegg |first2=K.|author2-link=Kathrin Altwegg |last3=Brown |first3=R.H. |title=JET: Journey to Enceladus and Titan |url=http://www.lpi.usra.edu/meetings/lpsc2011/pdf/1326.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.lpi.usra.edu/meetings/lpsc2011/pdf/1326.pdf |archive-date=2022-10-09 |url-status=live |conference=42nd Lunar and Planetary Science Conference |publisher=Lunar and Planetary Institute |date=2011 |display-authors=etal}}</ref><ref name="JET 204">{{cite news |last=Kane |first=Van |title=Discovery Missions for an Icy Moon with Active Plumes | url=http://www.planetary.org/blogs/guest-blogs/van-kane/20140402-discovery-missions-for-an-icy-moon-with-plumes.html| work=The Planetary Society |date=3 April 2014 |access-date=9 April 2015 }}</ref><ref name="LCPM-2013">{{cite conference |last1=Matousek |first1=Steve |last2=Sotin |first2=Christophe |last3=Goebel |first3=Dan |last4=Lang |first4=Jared |title=JET: Journey to Enceladus and Titan |url=http://lcpm10.caltech.edu/pdf/session-5/3_JET-LCPM-130618-Matousek-final.pdf |conference=Low Cost Planetary Missions Conference |publisher=California Institute of Technology |date=18–21 June 2013 |access-date=10 April 2015 |archive-url=https://web.archive.org/web/20160304072017/http://lcpm10.caltech.edu/pdf/session-5/3_JET-LCPM-130618-Matousek-final.pdf |archive-date=4 March 2016 |url-status=dead  }}</ref>

;''Enceladus Life Finder''
''[[Enceladus Life Finder]]'' (''ELF'') is a proposed astrobiology mission concept for a space probe intended to assess the [[Planetary habitability|habitability]] of the [[Extraterrestrial liquid water#Enceladus|internal aquatic ocean]] of [[Enceladus]], [[Saturn]]'s [[moons of Saturn|sixth-largest moon]].<ref name="2015 LPSC">{{cite conference |last1=Lunine |first1=Jonathan I. | last2=Waite | first2=Jack Hunter Jr. |last3=Postberg |first3=Frank |last4=Spilker |first4=Linda J. |title=Enceladus Life Finder: The search for life in a habitable moon |url=http://www.hou.usra.edu/meetings/lpsc2015/pdf/1525.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.hou.usra.edu/meetings/lpsc2015/pdf/1525.pdf |archive-date=2022-10-09 |url-status=live |conference=46th Lunar and Planetary Science Conference |publisher=Lunar and Planetary Institute |place=Houston (TX) |year=2015 }}</ref><ref name="contestants">{{cite news |last=Clark |first=Stephen |url=http://spaceflightnow.com/2015/04/06/diverse-destinations-considered-for-new-interplanetary-probe/ |title=Diverse destinations considered for new interplanetary probe |work=Space Flight Now |date=6 April 2015 |access-date=7 April 2015 }}</ref>

;''Life Investigation For Enceladus''
''[[Life Investigation For Enceladus]]'' (''LIFE'') is a proposed astrobiology sample-return mission concept. The spacecraft would enter into [[Saturn]] orbit and enable multiple flybys through Enceladus' icy plumes to collect icy plume particles and volatiles and return them to Earth on a capsule. The spacecraft may sample Enceladus' plumes, the [[Rings of Saturn#E Ring|E ring of Saturn]], and the upper atmosphere of [[Titan (moon)|Titan]].<ref name="Astro2012">{{cite journal |title= Life Investigation For Enceladus A Sample Return Mission Concept in Search for Evidence of Life. |journal=Astrobiology |date=August 2012 |last1=Tsou |first1=Peter |last2=Brownlee |first2=D.E. |first3=Christopher |last3=McKay |last4=Anbar |first4=A.D. |last5= Yano |first5=H. |volume=12 |issue=8 |pages=730–742 |doi=10.1089/ast.2011.0813 |bibcode = 2012AsBio..12..730T |pmid=22970863}}</ref><ref name="Porco 2014">{{cite journal |title=Life – Enceladus Plume Sample Return via Discovery |journal=45th Lunar and Planetary Science Conference |year=2014 |last1=Tsou |first1=Peter |last2=Anbar |first2=Ariel |last3=Atwegg |first3=Kathrin |last4=Porco |first4=Carolyn |last5=Baross |first5=John |last6=McKay |first6=Christopher |issue=1777 |pages=2192 |bibcode=2014LPI....45.2192T |url=http://www.hou.usra.edu/meetings/lpsc2014/pdf/2192.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.hou.usra.edu/meetings/lpsc2014/pdf/2192.pdf |archive-date=2022-10-09 |url-status=live |access-date=10 April 2015 }}</ref><ref name="Doc 2013">{{cite journal|url=http://discoveringenceladus.com/downloads/LIFE%20-%20Life%20Investigation%20For%20Enceladus%20-%20A%20Sample%20Return%20Mission%20Concept%20in%20Search%20for%20Evidence%20of%20Life.doc |format=.doc |title=Life Investigation For Enceladus – A Sample Return Mission Concept in Search for Evidence of Life. |last=Tsou |first=Peter |journal=Jet Propulsion Laboratory |date=2013 |volume=12 |issue=8 |pages=730–742 |doi=10.1089/ast.2011.0813 |access-date=10 April 2015 |url-status=dead |archive-url=https://web.archive.org/web/20150901121008/http://discoveringenceladus.com/downloads/LIFE%20-%20Life%20Investigation%20For%20Enceladus%20-%20A%20Sample%20Return%20Mission%20Concept%20in%20Search%20for%20Evidence%20of%20Life.doc |archive-date=1 September 2015  |pmid=22970863 |bibcode=2012AsBio..12..730T }}</ref>

;''Oceanus''
[[Oceanus (Titan orbiter)|''Oceanus'']] is an orbiter proposed in 2017 for the [[New Frontiers program|New Frontiers]] mission No. 4. It would travel to the moon of [[Saturn]], [[Titan (moon)|Titan]], to assess its [[Planetary habitability|habitability]].<ref name=sotin>{{cite conference |last1= Sotin|first1= C.|last2= Hayes|first2= A.|last3= Malaska|first3= M.|last4= Nimmo|first4= F.|last5= Trainer|first5= M. |first6 =M.|last6= Mastrogiuseppe|first7= J.|last7= Soderblom|first8= P.|last8= Tortora|first9= J.|last9= Hofgartner|first10=O.|last10= Aharonson|first11=J. W.|last11= Barnes|first12= R.|last12= Hodyss|first13= L.|last13 = Iess|first14 = R.|last14= Kirk|first15= P.|last15 = Lavvas|first16 = R.|last16 = Lorenz |first17=Jonathan I. |last17=Lunine |first18=E.|last18 = Mazarico|first19=A.|last19= McEwen|first20= C. |last20 = Neish|first21=C.|last21= Nixon|first22=E.|last22= Turtle|first23 =  V.|last23= Vuitton|first24= R.|last24= Yelle|display-authors = 6 |url = http://www.hou.usra.edu/meetings/lpsc2017/pdf/2306.pdf|title= Oceanus: A New Frontiers orbiter to study Titan's potential habitability |conference= 48th Lunar and Planetary Science Conference|date= 20–24 March 2017 |location = The Woodlands, Texas}}</ref> ''Oceanus''{{'}} objectives are to reveal Titan's [[organic chemistry]], geology, gravity, topography, collect 3D reconnaissance data, catalog the [[Organic compound|organics]] and determine where they may interact with liquid water.<ref>{{cite conference|last1 =Tortora |first1= P.|last2= Zannoni|first2= M.|last3= Nimmo|first3= F.|last4= Mazarico|first4= E.|last5= Iess|first5= L.|last6= Sotin|first6= C. |last7= Hayes|first7= A.|last8= Malaska|first8= M.|title=Titan gravity investigation with the Oceanus mission|journal= EGU General Assembly Conference Abstracts|volume= 19|conference= 19th EGU General Assembly, EGU2017|date= 23–28 April 2017 |page = 17876|bibcode= 2017EGUGA..1917876T}}</ref>

;''Explorer of Enceladus and Titan''
''[[Explorer of Enceladus and Titan]]'' ('''E<sup>2</sup>T''') is an orbiter mission concept that would investigate the evolution and [[Planetary habitability|habitability]] of the Saturnian satellites [[Enceladus (moon)|Enceladus]] and [[Titan (moon)|Titan]]. The mission concept was proposed in 2017 by the [[European Space Agency]].<ref name='E2T 2017'>{{cite journal |title=Explorer of Enceladus and Titan (E2T): Investigating the habitability and evolution of ocean worlds in the Saturn system |journal=American Astronomical Society |year=2017|url=https://e2tmission.wordpress.com/ |author1=Mitri, Giuseppe |author2=Postberg, Frank |author3=Soderblom, Jason M. |author4=Tobie, Gabriel |author5=Tortora, Paolo |author6=Wurz, Peter |author7=Barnes, Jason W. |author8=Coustenis, Athena |author9=Ferri, Francesca |author10=Hayes, Alexander |author11=Hayne, Paul O. |author12=Hillier, Jon |author13=Kempf, Sascha |author14=Lebreton, Jean-Pierre |author15=Lorenz, Ralph |author16=Orosei, Roberto |author17=Petropoulos, Anastassios |author18=Yen, Chen-wan |author19=Reh, Kim R. |author20=Schmidt, Jürgen |author21=Sims, Jon |author22=Sotin, Christophe |author23=Srama, Ralf |volume=48 |pages=225.01 |bibcode=2016DPS....4822501M |display-authors=6 |access-date=16 September 2017 }}</ref>