National Aeronautics and Space Administration Headquarters
Washington, DC 20546-0001
Reply to attn of: SR
May 5 1997
Dr. Claude Canizares
Space Studies Board
National Academy of Sciences
2101 Constitution Avenue, NW Washington, DC 20418
Dear Dr. Canizares:
NASA's planetary protection policy aims to preserve solar system conditions for future biological and organic constituent exploration and to protect the Earth and its biosphere from extraterrestrial sources of contamination. The Space Studies Board (SSB) has been the primary group advising NASA on its efforts in planetary protection and continued advice is needed to ensure that our planetary protection policy remains sound. In particular, we continue to seek the Space Studies Board's advice on issues and concerns about samples returned from planetary bodies.
The recent publication of the SSB report, Mars Sample Return: Issues and Recommendations has been timely in assisting us in the consideration of missions which will collect samples for possible return to Earth. The SSB has made valuable recommendations on the justification and procedures for quarantine of samples returned from Mars. Indeed, we expect that similar sample quarantine procedures may be applicable to any returned extraterrestrial material that may be a potential hazard to Earth's biosphere.
Recent data has indicated that the focus of our previous request on Mars sample return should be expanded to include other solar system bodies. For example, natural satellites, asteroids, and comets represent a wide range of bodies from which NASA may someday take and perhaps return a sample, not only during missions such as Rosetta, but also during missions proposed to NASA's Discovery Program and in our possible joint work with the Department of Defense. With the advent of possible sample return missions from multiple planetary bodies, we feel that it would be prudent to initiate a study that would extend current advice on Mars to other small solar system bodies by addressing:
The potential for a living entity to be in a sample returned from different planetary bodies, such as satellites, comets and asteroids;
Detectable differences among small bodies that would affect the above assessment;
Scientific investigations that should be conducted to reduce the uncertainty in the above assessment;
The potential risk from samples returned directly to Earth by space flight missions, as compared to the natural influx of material that enters the Earth's atmosphere as interplanetary dust particles, meteorites, and other small impactors.
Your help in addressing the question of planetary protection for missions that may return material from a wide range of small bodies is greatly appreciated. Dr. Meyer will be working with you and the SSB staff to finalize a Statement of Task for this study effort. Please contact him (202-358-0307) if you need further information about this request.