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 subsurface life.[1][2][3]
Concept
ExoLance was conceived by Dr. Steve McDaniel and is 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 metabolic or nucleic acid detection/identification test that would attempt to detect active metabolism or nucleic acids created by any active microorganisms living one to two meters below the surface.[1][2] The concept is an outgrowth of a device created by Dr. Gil Levin where 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.[3] The conception is an example of fostering scientific collaborations for which Explore Mars was established by founders Artemis Westenberg, Chris Carberry, Gary Fisher and Steve McDaniel.
In October of 2012, Explore Mars held another of its Humans to Mars conferences to foster such collaborations. A panel was organized comprised of Drs. Steve McDaniel (organizer and moderator), Penny Boston, Gil Levin and Andrew Steele, all experts in exobiology in one way or another. The debate was whether or not Mars hosted extant life. Dr. Chris McKay was asked to be there and counter Levin and McDaniel, with Boston as a middle roader. McKay and Levin were so contrary at that time, that McKay declined and recommended another NASA funded researcher – Steele. A video was created for the debate by McDaniel and Mars graphic artist Gus Frederick.
Soon after the debate, McDaniel engaged McKay again and asked if he would be willing to debate he and Levin in a high-profile Huffington Post “Pro vs. Con” format. McKay accepted and that piece was published. It further fanned the flames. Levin and McDaniel stuck to their “Viking landers have already proven it” thesis and McKay stuck to his “Not yet – extraordinary claims require extraordinary proof.”
McDaniel had been intrigued with Levin’s “next version” of the Viking lander – the Chiral LR Dart – that was designed to repeat the chemistry but use chirality to distinguish biotic versus abiotic oxidation of the sugar. It was designed to only penetrate the first few centimeters and sample at that level, because Levin believed that the Viking landers on which he was a principal investigator in the 1970s had detected life on the Martian topsoil. McKay that had tested Levin’s approach to life detection in the Atacama desert and had concluded that the technique had indeed worked to detect very scant life. Still, McKay believed the problem on Mars was that at least the first so many centimeters of the Martian soil was completely sterilized, and that definitive testing would require probing down several meters – a feat no Mars rover had yet, nor was presently designed, to do. Steve was also aware that Joe Cassidy’s company AeroJet Rocketdyne built bunker-busting bombs for the DoD. He called Joe and asked “How low can we go, Joe?” Joe’s answer was “As deep as you need.” McDaniel put two-and-two together - a chiral LR dart and a deep penetrator - and the concept sorang forth.
McDaniel, Levin, McKay, Cassidy and Chris Carberry met to discuss implementing the concept. Mcdaniel asked Levin if he would be willing to modify his LCR dart design to go very deep. He said “Yes.” Cassidy was asked if AeroJet RocketDyne would build prototypes and test them and it looked likely. Carberry as Executive Director of Explore Mars said that the organization would organize a funding approach. But, the burning question in everyone’s mind was what would the NASA response be to this novel approach. So, at the conclusion of the meeting, McDaniel asked McKay if he would publicly acknowledge that he believed it would give the definitive proof - extant Martian microbes, yeah or nay. McKay said “Hell Yes!” and further offered that he had been hoping for a project like this for years. The project was off and running.
Aerojet Rocketdyne is performing computer modeling of the Mars penetrators as a design tool.[4] A new company called ExoLife 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 RocketDyne and ExoLife) will approach space agencies and potential commercial providers to carry ExoLance on one or more future Mars missions.[4]
The science team is presently comprised of astrobiologists Christopher McKay, Steve McDaniel and engineers Gilbert Levin and Joe Cassidy.[5]
Subsurface habitability
Although Mars soils are likely not to be overtly toxic to terrestrial microorganisms,[4] life on the surface of Mars is extremely unlikely because it is bathed in radiation and it is completely frozen. [5][6][7][8][9][10][11] Therefore, the best potential locations for discovering life on Mars may be at subsurface environments that have not been studied yet.[11][12][13][14][15][16]
See also
References
- ^ Foust, Jeff (5 May 2014). "Mars missions on the cheap". The Space Review. Retrieved 2014-05-06.
- ^ "ExoLance". Explore Mars Inc. 2014. Retrieved 2014-05-06.
- ^ Koebler, Jason (24 April 2014). "Blasting Mars with Missiles Is the Latest Hope for Finding Martian Life". Motherboard. Retrieved 2014-05-06.
- ^ Conrad, P. G.; Archer, D.; Coll, P.; De La Torre, M.; Edgett, K.; Eigenbrode, J. L.; Fisk, M.; Freissenet, C.; Franz, H.; et al. (2013). "Habitability Assessment at Gale Crater: Implications from Initial Results". 44th Lunar and Planetary Science Conference 1719: 2185. Bibcode:2013LPICo1719.2185C.
- ^ Than, Ker (January 29, 2007). "Study: Surface of Mars Devoid of Life". Space.com.
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.
- ^ Dartnell, L. R.; Desorgher, L.; Ward, J. M.; Coates, A. J. (2007). "Modelling the surface and subsurface Martian radiation environment: Implications for astrobiology". Geophysical Research Letters 34 (2): L02207. Bibcode:2007GeoRL..34.2207D. doi:10.1029/2006GL027494.
Bacteria or spores held dormant by freezing conditions cannot metabolise and become inactivated by accumulating radiation damage. We find that at 2 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.
- ^ Lovet, Richard A. (February 2, 2007). "Mars Life May Be Too Deep to Find, Experts Conclude". National Geographic News.
- ^ Dartnell, L. R.; Desorgher, L.; Ward, J. M.; Coates, A. J. (2007). "Modelling the surface and subsurface Martian radiation environment: Implications for astrobiology". Geophysical Research Letters 34 (2). Bibcode:2007GeoRL..3402207D. doi:10.1029/2006GL027494.
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.
- ^ Dartnell, L. R.; Desorgher, L.; Ward, J. M.; Coates, A. J. (2007). "Martian sub-surface ionising radiation: biosignatures and geology". Biogeosciences 4 (4): 545–558. Bibcode:2007BGeo....4..545D. doi:10.5194/bg-4-545-2007.
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.
- ^ Dartnell, Lewis R.; Storrie-Lombardi, Michael C.; Muller, Jan-Peter; Griffiths, Andrew. D.; Coates, Andrew J.; Ward, John M. (March 7–11, 2011). "42nd Lunar and Planetary Science Conference" (PDF) . The Woodlands, Texas: Lunar and Planetary Institute.
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ignored (help) - ^ a b "Scientists find evidence Mars subsurface could hold life". Digital Journal – Science. January 21, 2013.
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.
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missing|last1=
in Authors list (help) - ^ Summons, Roger E.; Amend, Jan P.; Bish, David; Buick, Roger; Cody, George D.; Des Marais, David J.; Dromart, Gilles; Eigenbrode, Jennifer L.; et al. (2011). "Preservation of Martian Organic and Environmental Records: Final Report of the Mars Biosignature Working Group". Astrobiology 11 (2): 157–81. Bibcode:2011AsBio..11..157S. doi:10.1089/ast.2010.0506. PMID 21417945.
There is general consensus that extant microbial life on Mars would probably exist (if at all) in the subsurface and at low abundance.
- ^ Steigerwald, Bill (January 15, 2009). "Martian Methane Reveals the Red Planet is not a Dead Planet". NASA's Goddard Space Flight Center (NASA). Archived from the original on 2009-01-16.
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
- ^ "Mars Rovers Sharpen Questions About Livable Conditions". NASA. Archived from the original on 2008-02-18.
- ^ "Mars: 'Strongest evidence' planet may have supported life, scientists say". BBC News. January 20, 2013.
- ^ Michalski, Joseph R.; Cuadros, Javier; Niles, Paul B.; Parnell, John; Deanne Rogers, A.; Wright, Shawn P. (2013). "Groundwater activity on Mars and implications for a deep biosphere". Nature Geoscience 6 (2): 133–8. Bibcode:2013NatGe...6..133M. doi:10.1038/ngeo1706.
External links
- Meeting presentation of ExoLance (YouTube video) 16 min.
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