First International Conference on Mars Sedimentology and Stratigraphy (2010) 6024.pdf

SEDIMENTOLOGY, STRATIGRAPHY AND ASTROBIOLOGY ON MARS IN 2018, POTENTIALLY USING TWO ROVERS. D.W. Beaty1, A.C. Allwood1, J. Vago2, and F. Westall3, 1Mars Program Office, JPL/Caltech, 2European Space Agency, 3CNRS, France. Correspondence address: [email protected].

Detailed study of the sedimentary record on Mars, cerning the possible influence of microbiological both by in situ methods and by means of sample return, processes. The proposed MAX-C rover would also is becoming progressively more important as our Mars collect and cache shallow (~10cm depth) core samples exploration strategies evolve from “follow the water” for possible return to Earth by a future mission. and “seeking habitable environments” to “seeking evi- The ExoMars rover would include cameras and a dence of life” [1]. A key mission in the future explora- close-up imager for surface studies, and would be able tion sequence is the proposed 2018 joint NASA-ESA to investigate the shallow subsurface stratigraphy with rover mission, that would have both advanced capabili- ground penetrating radar, drill to 2m depth, measure ties for in situ science, and would collect and cache compositional variations of the borehole walls, and samples for possible subsequent return to Earth. collect and analyze small core samples with an on- Present plans for the 2018 mission envision landing board analytical laboratory. The laboratory would two rovers at the same site. The potential NASA- include a mass spectrometer for detecting and charac- provided Mars Astrobiology Explorer-Cacher (MAX- terizing a broad array of organic molecules, a competi- C) rover and the ESA-provided Exo-Mars rover would tive immunoassay laboratory-on-a-chip sensor for de- have separately defined objectives related to seeking tecting specific biomarkers, a microscope (15 µm reso- evidence of past - and possibly also present - life on lution), and instruments for mineralogy analyses in- Mars, in an environment with high inferred habitability cluding X-ray diffraction and IR and Raman spectro- potential. Possible collaborative science for the two meters. A range of potential collaborative possibilities rovers operating together is under discussion. The arise from the currently envisioned payloads of the two landing site for this potential two-rover mission proba- rovers, or from small modifications of those payloads. bly would contain sedimentary rocks, as subaqueously Possible exploration strategies: The rover Oppor- deposited sediments are among the most prospective tunity demonstrated the first in situ sedimentolo- kinds of geologic environments in which to pursue gy/stratigraphy studies on another planet, and that ex- these objectives. perience constitutes a valuable guide for future explo- If a sedimentary site is chosen for this proposed ration approaches. If the MSL (2011) landing site is in mission, the rovers would need to carry out a robust sedimentary terrane (that decision is still pending), the sedimentological field study, not only to maximize the MSL rover’s experiences will further expand our un- chances of detecting potential biosignatures and select- derstanding of exploration strategies. For the proposed ing the best samples for analysis or possible return, but 2018 rovers, there are two important kinds of open – crucially – to have the necessary contextual informa- planning questions. Firstly, how should the two rovers tion to interpret potential biosignatures if any are found be equipped (in the case of MAX-C, the instruments either in situ or upon return to Earth. have not yet been selected). Secondly, how should the Science measurement capabilities: The two rov- rover capabilities be used, separately and jointly, to ers would have different and complementary mea- interrogate sedimentary rocks? Another important con- surement approaches. The potential MAX-C science sideration would be how to balance the collection of payload would have an approach similar to that on the compelling samples (which are best recognized after a Mars Exploration Rovers (MER), focused on analysis certain amount of field analysis has been conducted) of outcrops through arm- and mast-mounted instru- against the ticking mission clock and limited number ments, rather than onboard analysis of samples. How- of opportunities to collect samples. ever, MAX-C would have significantly updated in- References: [1] http://mepag/meeting/jul- struments compared to MER, with the arm-mounted 09/MEPAG_DSMustard_07-2009-v9.ppt; [2] instruments capable of compositional micro-mapping MEPAG Mars Astrobiology Explorer - Cacher (MAX- rather than bulk compositional analysis. MAX-C C) (2009) http://mepag.jpl.nasa.gov/reports/ index.html would also have an instrument capable of detecting and micro-mapping organics. In effect, the envisioned MAX-C payload could carry out spatially-resolved geochemistry and rudimentary field petrography. These capabilities would be crucial for interpreting depositional and post-depositional history, and for dis-