View source for ExoLance

{{short description|Low-cost mission concept to Mars}}
'''ExoLance''' is a low-cost mission concept that could hitch a ride on other missions to [[Mars]] in an effort to look for evidence of [[Life on Mars|subsurface life]].<ref name="Review 2014">{{cite news |last=Foust |first=Jeff |url=http://www.thespacereview.com/article/2506/1 |title=Mars missions on the cheap |work=The Space Review |date=5 May 2014 |access-date=2014-05-06 }}</ref><ref name="ExoLance home">{{cite web |url=http://exploremars.org/exolance/ |title=ExoLance |work=Explore Mars Inc. |date=2014 |access-date=2014-05-06 |archive-date=2014-05-06 |archive-url=https://web.archive.org/web/20140506212506/http://exploremars.org/exolance/ |url-status=dead }}</ref><ref name="Motherboard 2014">{{cite news |last=Koebler |first=Jason |title=Blasting Mars with Missiles Is the Latest Hope for Finding Martian Life |work=Motherboard |date=24 April 2014 |url=http://motherboard.vice.com/read/a-new-scheme-for-finding-alien-life-blasting-mars-with-bunker-buster-missiles |access-date=2014-05-06 }}</ref>
==Concept==
The ExoLance concept was conceived in 2014 by Steve McDaniel and consists in an impact penetrator that would fly to Mars as a secondary payload on a future Mars lander mission. A Mars lander would carry a set of ExoLance penetrators, each weighing a few kilograms. The penetrators would separate as the lander spacecraft enters the Martian atmosphere, passively falling to the Martian surface. The penetrators would make use of technology originally developed for "[[bunker buster]]" munitions, which are designed to burrow under the surface before exploding. In this case, the explosive payload would be replaced by a scientific one, specifically, a [[Metabolism|metabolic test]] that would attempt to detect chemical reactions created by any active [[microorganism]]s living one to two meters below the surface.<ref name="Review 2014"/><ref name="ExoLance home"/> The rear end of the penetrator would remain on the surface, connected to the buried probe by a cable, to provide a communications link to orbiting satellites. Having multiple probes allows for individual probe failures without losing the entire mission. The goal is to create something that is both small enough and affordable enough to be able to be put on several planned flights.<ref name="Motherboard 2014"/>
Aerojet Rocketdyne is performing computer modeling of the Mars penetrators  as a design tool.<ref name='Carberry'>[https://www.indiegogo.com/projects/exolance Are you ready to answer the question, are we alone in the universe? ExoLance is] Chris Carberry. ''Indiegogo''.</ref> A company called ExoLife Inc. has patented the improved deep penetrator designed to carry life-detection equipment and has licensed critical, self-sterilizing coating technology for the penetrators. ExoLife is testing the detection equipment and self-sterilizing surface technology that will be carried as the payloads.  Once the concept is sufficiently tested and has been proven, 'Explore Mars' in collaboration with its corporate partners (AeroJet and ExoLife) will approach space agencies and potential commercial providers to carry ExoLance on one or more future Mars missions.<ref name='Carberry'/>
The science team is composed of astrobiologists [[Christopher McKay]], Steve McDaniel and engineers [[Gilbert Levin]] and Joe Cassidy.<ref>[http://exploremars.org/exolance/the-team/ ExoLance Team] {{webarchive|url=https://web.archive.org/web/20140506202750/http://exploremars.org/exolance/the-team/ |date=2014-05-06 }} (2014).</ref>
==Subsurface habitability==
{{main|Life on Mars#Subsurface}}
Although Mars soils are likely not to be overtly toxic to terrestrial microorganisms,<ref name="2013 LPS">{{cite journal |bibcode=2013LPI....44.2185C |title=Habitability Assessment at Gale Crater: Implications from Initial Results |last1=Conrad |first1=P. G. |last2=Archer |first2=D. |last3=Coll |first3=P. |last4=De La Torre |first4=M. |last5=Edgett |first5=K. |last6=Eigenbrode |first6=J. L. |last7=Fisk |first7=M. |last8=Freissenet |first8=C. |last9=Franz |first9=H. |last10=Glavin |first10=D. P. |last11=Gómez |first11=F. |last12=Haberle |first12=R. |last13=Hamilton |first13=V. |last14=Jones |first14=J. H. |last15=Kah |first15=L. C. |last16=Leshin |first16=L. A. |last17=Mahaffy |first17=P. M. |last18=McAdam |first18=A. |last19=McKay |first19=C. P. |last20=Navarro-González |first20=R. |last21=Steele |first21=A. |last22=Stern |first22=J. |last23=Sumner |first23=D. |last24=Treiman |first24=A. H. |last25=Wong |first25=M. H. |last26=Wray |first26=J. |last27=Yingst |first27=R. A. |author28=MSL Science Team |display-authors=9 |volume=1719 |issue=1719 |year=2013 |pages=2185 |journal=44th Lunar and Planetary Science Conference }}</ref> life on the surface of Mars is extremely unlikely because it is bathed in radiation and it is completely frozen.<ref name="cosmic radiation">{{cite web | url = http://www.space.com/3396-study-surface-mars-devoid-life.html | title = Study: Surface of Mars Devoid of Life | first=Ker | last=Than | date=January 29, 2007 | work=Space.com | quote=After mapping cosmic radiation levels at various depths on Mars, researchers have concluded that any life within the first several yards of the planet's surface would be killed by lethal doses of cosmic radiation.}}</ref><ref name="Dartnell">{{cite journal |doi=10.1029/2006GL027494 |quote=Bacteria or spores held dormant by freezing conditions cannot metabolise and become inactivated by accumulating radiation damage. We find that at 2&nbsp;m depth, the reach of the ExoMars drill, a population of radioresistant cells would need to have reanimated within the last 450,000 years to still be viable. Recovery of viable cells cryopreserved within the putative Cerberus pack-ice requires a drill depth of at least 7.5 m. |title=Modelling the surface and subsurface Martian radiation environment: Implications for astrobiology |year=2007 |last1=Dartnell |first1=L. R. |last2=Desorgher |first2=L. |last3=Ward |first3=J. M. |last4=Coates |first4=A. J. |journal=Geophysical Research Letters |volume=34 |issue=2 |pages=L02207 | bibcode= 2007GeoRL..34.2207D |s2cid=59046908 |url=http://discovery.ucl.ac.uk/134609/1/2006GL027494.pdf }}</ref><ref name="Dartnell_Geographic">{{cite web | first=Richard A. | last=Lovet | title=Mars Life May Be Too Deep to Find, Experts Conclude | url=http://news.nationalgeographic.co.uk/news/2007/02/070202-mars-life.html | work=National Geographic News | date=February 2, 2007 | url-status=dead | archive-url=https://web.archive.org/web/20140221095944/http://news.nationalgeographic.co.uk/news/2007/02/070202-mars-life.html | archive-date=February 21, 2014 }}</ref><ref name="Dartnell-1">{{cite journal |bibcode=2007GeoRL..34.2207D |doi=10.1029/2006GL027494 |quote=The damaging effect of ionising radiation on cellular structure is one of the prime limiting factors on the survival of life in potential astrobiological habitats. |title=Modelling the surface and subsurface Martian radiation environment: Implications for astrobiology |year=2007 |last1=Dartnell |first1=L. R. |last2=Desorgher |first2=L. |last3=Ward |first3=J. M. |last4=Coates |first4=A. J. |journal=Geophysical Research Letters |volume=34 |issue=2|pages=L02207 |s2cid=59046908 |url=http://discovery.ucl.ac.uk/134609/1/2006GL027494.pdf }}</ref><ref name="ionising radiation">{{cite journal | title=Martian sub-surface ionising radiation: biosignatures and geology | journal=Biogeosciences | year=2007 | first1=L. R. |last1=Dartnell |first2=L. |last2=Desorgher |first3=J. M. |last3=Ward |first4=A. J. |last4=Coates | volume=4 | pages=545–558 | doi=10.5194/bg-4-545-2007 | bibcode=2007BGeo....4..545D | quote=This ionising radiation field is deleterious to the survival of dormant cells or spores and the persistence of molecular biomarkers in the subsurface, and so its characterisation. [..] Even at a depth of 2 meters beneath the surface, any microbes would probably be dormant, cryopreserved by the current freezing conditions, and so metabolically inactive and unable to repair cellular degradation as it occurs. | issue = 4| url=http://hal.archives-ouvertes.fr/docs/00/29/76/31/PDF/bg-4-545-2007.pdf | doi-access=free }}</ref><ref>{{cite conference |first1=Lewis R. |last1=Dartnell |first2=Michael C. |last2=Storrie-Lombardi |first3=Jan-Peter |last3=Muller |first4=Andrew. D. |last4=Griffiths |first5=Andrew J. |last5=Coates |first6=John M. |last6=Ward |title=Implications of cosmic radiation on the Martian surface for microbial survival and detection of fluorescent biosignatures |book-title=42nd Lunar and Planetary Science Conference |publisher=[[Lunar and Planetary Institute]] |place=The Woodlands, Texas |date=March 7–11, 2011 |url=http://www.lpi.usra.edu/meetings/lpsc2011/pdf/1977.pdf }}</ref><ref name="Parnell">{{cite news | first1=JohnThomas|last1=Didymus | title=Scientists find evidence Mars subsurface could hold life | date=January 21, 2013 | url=http://digitaljournal.com/article/341801 | work = Digital Journal – Science | quote=There can be no life on the surface of Mars because it is bathed in radiation and it's completely frozen. However, life in the subsurface would be protected from that. - Prof. Parnell.}}</ref> Therefore, the best potential locations for discovering life on Mars may be at subsurface environments that have not been studied yet.<ref name="Parnell" /><ref name="Biosignatures 2011">{{cite journal | doi=10.1089/ast.2010.0506 | quote=There is general consensus that extant microbial life on Mars would probably exist (if at all) in the subsurface and at low abundance. | title=Preservation of Martian Organic and Environmental Records: Final Report of the Mars Biosignature Working Group | year=2011 | last1=Summons | first1=Roger E. | last2=Amend | first2=Jan P. | last3=Bish | first3=David | last4=Buick | first4=Roger | last5=Cody | first5=George D. | last6=Des Marais | first6=David J. | last7=Dromart | first7=Gilles | last8=Eigenbrode | first8=Jennifer L. | last9=Knoll | first9=Andrew H. | last10=Sumner | first10=Dawn Y. | display-authors=8 | journal=Astrobiology | volume=11 | issue=2 | pages=157–81 | pmid=21417945 | bibcode = 2011AsBio..11..157S | hdl=1721.1/66519 | s2cid=9963677 | hdl-access=free }}</ref><ref name="Steigerwald">{{cite news | first=Bill | last=Steigerwald | title=Martian Methane Reveals the Red Planet is not a Dead Planet | date=January 15, 2009 | publisher=[[NASA]] | url=http://www.nasa.gov/mission_pages/mars/news/marsmethane.html | work=NASA's Goddard Space Flight Center | url-status=live | archive-date=2009-01-16 | archive-url=https://web.archive.org/web/20090116151746/http://www.nasa.gov/mission_pages/mars/news/marsmethane.html |quote=If microscopic Martian life is producing the methane, it probably resides far below the surface, where it's still warm enough for liquid water to exist }}</ref><ref>{{cite web | url=http://marsrovers.jpl.nasa.gov/newsroom/pressreleases/20080215a.html | publisher=NASA | title=Mars Rovers Sharpen Questions About Livable Conditions | url-status=live | archive-date=2008-02-18 | archive-url=https://web.archive.org/web/20080218185133/http://marsrovers.jpl.nasa.gov/newsroom/pressreleases/20080215a.html }}</ref><ref>{{cite news | title=Mars: 'Strongest evidence' planet may have supported life, scientists say | date=January 20, 2013 | url=https://www.bbc.co.uk/news/uk-scotland-north-east-orkney-shetland-21063817 | work=[[BBC News]] }}</ref><ref>{{cite journal |doi=10.1038/ngeo1706 |title=Groundwater activity on Mars and implications for a deep biosphere |year=2013 |last1=Michalski |first1=Joseph R. |last2=Cuadros |first2=Javier |last3=Niles |first3=Paul B. |last4=Parnell |first4=John |last5=Deanne Rogers |first5=A. |last6=Wright |first6=Shawn P. |journal=Nature Geoscience |volume=6 |issue=2 |pages=133–8|bibcode = 2013NatGe...6..133M }}</ref>
==See also==
*[[Astrobiology]]
*[[Life on Mars]]
==References==
{{reflist|2}}
==External links==
*[https://www.youtube.com/watch?v=gpRGvVxLnhg Meeting presentation of ExoLance], a YouTube video, 16 min.
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[[Category:Proposed astrobiology space missions]]