Strategies for Investigating Martian Microenvironments for Evidence of Life: The Expedition One Experience

Abstract

While it is not known whether life ever existed on Mars, answering this question is a major rationale for human exploration. The search for extant or fossil life necessarily will be conducted in collaboration with geological analysis to identify microenvironments favorable to life forms that may have evolved a unique biochemistry. A proposed exploration strategy, assuming a base installation with extensive research and communication equipment, involves sorties of days to a few weeks by parties of three persons. Two types of vehicles will be needed: a pressurized research rover (PRR) with adequate living quarters and a small field laboratory, and one or more faster, non-pressurized 4-person vehicles (SRV) for scouting, re-supply, and rescue. A day on sortie would include one or more EVAs, analysis of samples and instrument data, communication with personnel at the base, and maintenance of all research and engineering systems. It is essential that some sample analysis take place during the sortie in order to guide further choice of sampling sites and to preserve raw data in the event of astronaut loss. Analog research such as Expedition One is invaluable to assess exploration strategy and to indicate areas for future design. For example, field equipment and techniques must permit rapid sampling and measurement, because the air supply on EVA is limited. All collection components must be fully integrated with analysis systems on the PRR and at the base. Consumable items for analysis will be limited by the constraints of payload weight; thus each test performed must answer a particular question. While robotic exploration components augment human capabilities in some circumstances, our experience during Expedition One indicates that human effort will be required to study some sites of particular biological interest. A crucial requirement of human exploration, however, is the avoidance of contamination of sampling sites with Earth origin organisms or organic compounds.