From Mars Pathfinder to Mars Express, Mars Reconnaissance Orbiter, and the Mars Exploration Rovers Spirit and Opportunity, the recent spate of robotic missions to the Red Planet has led to a wealth of new information about the planet’s environment, including strong evidence of a watery past and the possible discovery of atmospheric methane. In addition, new developments in our understanding of life in extreme conditions on Earth suggest the possibility of microbial viability in the harsh martian environment. Together, these results have greatly increased interest in the search for life on Mars, both within the scientific community and beyond.
Such scientific interest achieved a new focus on January 14, 2004, when President George W. Bush announced the new Vision for Space Exploration, directing NASA to focus its efforts on robotic and human exploration of space, particularly of the Moon and Mars. Included in the Vision is an explicit directive to “[c]onduct robotic exploration of Mars to search for evidence of life ….”
Given the enhanced scientific and political interest in the search for life on Mars, it is surprising that NASA’s most recent end-to-end strategy for the detection of martian life, contained in the report An Exobiological Strategy for Mars Exploration, was published as long ago as 1995.
Against this backdrop, NASA’s Science Mission Directorate requested the Space Studies Board’s assistance in developing an up-to-date integrated astrobiology strategy for Mars exploration that brings together all the threads of this diverse topic into a single source for science mission planning. In particular, NASA asked that the strategy developed by the Committee on an Astrobiology Strategy for the Exploration of Mars address the following topics:
The characteristics of potential targets for Mars exploration particularly suited for elucidating the prebiotic and possibly biotic history of Mars, and methods for identifying these targets;
A catalog of biosignatures that reflect fundamental and universal characteristics of life (i.e., not limited to an Earth-centric perspective);
Research activities that would improve exploration methodology and instrumentation capabilities to enhance the chances of astrobiological discovery; and
Approaches to the exploration of Mars that would maximize the astrobiological science return.