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M. Cabane (Service d'Aéronomie), P. Coll (LISA), G. Israel (Service d'Aéronomie), F. Raulin (LISA), H. Niemann, P. Mahaffy (NASA Goddard Space Flight Center), R. Sternberg, C. Rodier (LISA), P. Rannou (Service d'Aéronomie)
In the frame of the future Mars exploration, we propose SAM (SAMPLE_ANALYSIS_ON_MARS), which will analyze the Martian ground and underground, searching for informations linked to extinct or extant traces of life, or prebiotic chemistry that could have existed on Mars. The previous missions on Mars that made such investigations have failed to obtain significant results; If there were potential informations, the lack of results may be interpreted following two ways. First, the photochemical oxidants may have destroyed the organics at mars surface, and it is necessary to drill at depths sufficient to attain zones preserved from oxidation. This will be performed by the drilling of Martian ground. Second, some of the preserved molecules may be too refractory to be pyrolyzed and analyzed by the classical methods (T=500K on Viking), and it is necessary to increase the oven temperature: we propose high temperature ovens on SAM (T=1000K). Moreover, the oxidation of organic molecules may give daughter molecules that are very fragile or very refractory : our new derivatization technique transforms these molecules into analyzable ones, and preserves the information. Other informations may be obtained from the heating at high temperature of the Martian samples, that may contain in their mineralogical composition crucial informations on the past Martian atmosphere. The heating of the sample to high temperatures (more than 800K) will let these minerals release their structural gases (H2O, CO2, SO2, etc.). The proposed experiment will associate pyrolysis and chemical derivatization and will analyze the gases produced after these processes, using the coupling of GC and MS, both techniques that we have developed in our laboratories, in the frame of previous space experiments. These techniques will also be used to perform measurements of the atmospheric composition, this complementary part of the experiment will be mainly performed by the US side of SAM.
The author(s) of this abstract have provided an email address for comments about the abstract: cabane@aero.jussieu.fr