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 sur veyor class missions. Looking for key organic compounds that are essential for biochemistry as we know it or indicative of extraterrestrial organic in flux 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 sensiti vity than the Viking GCMS experiment. MOD is not capable of identifying spe cific organic molecules but can assess the organic inventory of amines and PAHs on the planet. MOD can also quantify adsorbed and chemisorbed water an d evolved carbon dioxide in a stepped heating cycle to determine specific c arbon-bearing minerals. All that comes with no sample preparation and no we t chemistry. The organics can be isolated from the carrier matrix by heatin g the sample and recovering the volatile organics on a cold finger. This su blimation technique can be used for extracting amino acids, amines and PAHs under Mars ambient conditions. The detection of amino acids, amines and PA Hs is based on a fluorescence detection scheme. The MOD concept has functio ned as a laboratory breadboard since 1998. A number of natural samples incl uding shells, clays, bones, lambda -DNA and E.-coli bacteria have been used and organic molecules have been extracted successfully in each case. The f irst 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. (C) 2000 E lsevier Science Ltd. All rights reserved.