MOD: an organic detector for the future robotic exploration of Mars

Searching for extinct or extant life on Mars is part of the future NASA surveyor class missions. Looking for key organic compounds that are essential for biochemistry as we know it or indicative of extraterrestrial organic influx is the primary goal of the Mars Organic Detector (MOD). MOD is able to detect amino acids, amines and PAHs with at least 100 times higher sensitivity than the Viking GCMS experiment. MOD is not capable of identifying specific organic molecules but can assess the organic inventory of amines and PAHs on the planet. MOD can also quantify adsorbed and chemisorbed water and evolved carbon dioxide in a stepped heating cycle to determine specific carbon-bearing minerals. All that comes with no sample preparation and no wet chemistry. The organics can be isolated from the carrier matrix by heating the sample and recovering the volatile organics on a cold finger. This sublimation technique can be used for extracting amino acids, amines and PAHs under Mars ambient conditions. The detection of amino acids, amines and PAHs is based on a fluorescence detection scheme. The MOD concept has functioned as a laboratory breadboard since 1998. A number of natural samples including shells, clays, bones, λ-DNA and E.-coli bacteria have been used and organic molecules have been extracted successfully in each case. The first prototype of MOD is operational as of early fall of 1999. MOD has been selected for the definition phase of the NASA-MSR 2003 mission.