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Date: July 25, 2005
Contacts: Patrice Pages, Media Relations Officer
Michelle Strikowsky, Media Relations Assistant
Office of News and Public Information
202-334-2138; e-mail <>


New Measures Needed to Keep NASA Spacecraft From Contaminating Mars

WASHINGTON -- Over the coming decade, NASA should develop and implement new methods and requirements to detect and eliminate microorganisms on robotic spacecraft sent to Mars to prevent possible contamination of the planet, says a new report from the National Academies' National Research Council. If microbes aboard a spacecraft were to survive the trip to Mars and grow there, they could interfere with scientific investigations to detect any life that might be native to Mars. Existing techniques for cleaning spacecraft are outdated and typically eliminate only a fraction of microorganisms, said the committee that wrote the report.

Recent scientific findings suggest that liquid water could be present at many locations on Mars and that some organisms on Earth might survive in extreme, Mars-like conditions -- such as very low temperatures and high salt concentrations. These discoveries have bolstered the case that Mars could be -- or have been -- hospitable to life and have created urgency to update policies and practices to prevent Mars contamination, the report says.

"Ongoing Mars missions have shown that the planet may have environments where some Earth microbes could grow," said Christopher F. Chyba, committee chair and professor of astrophysics and international affairs at Princeton University, Princeton, N.J. "Although we don't know for sure if this could happen, we need to understand whether liquid water exists in Martian near-surface environments, as well as the nature of microorganisms that are in our clean rooms and spacecraft. It will take a while to carry out the needed research and development, so we need to start in earnest now."

NASA currently uses screening techniques that detect heat-resistant and spore-forming bacteria on spacecraft and then reduces their numbers by cleaning the spacecraft and, in certain circumstances, baking components with dry heat. But these screening methods are not designed to give a comprehensive tally of the microbes present on the spacecraft, and dry heat can be applied only to spacecraft materials that can withstand high temperatures, the report notes.

NASA should sponsor new research efforts aimed at preventing Mars contamination, the committee said, such as new techniques for detecting biological molecules that do not require time for growing laboratory cultures and could speed spacecraft sterilization and assembly in clean rooms. Also, methods that determine genetic sequences of organisms and link them to known microbial species could allow NASA to tailor sterilization techniques toward spacecraft contaminants of greatest concern. NASA should also investigate alternative cleaning methods -- such as the use of radiation or vapor disinfectants -- for their effectiveness in killing different types of microorganisms and for their effects on various spacecraft materials.

NASA should develop a certification process to compare detection and cleaning methods and select the most promising ones, begin testing and validating improved techniques within the next three years, and fully implement selected new techniques in time for spacecraft to launch in 2016. Until NASA conducts the research needed to transition to a modern approach for planetary protection, the agency should apply more stringent sterilization levels to all Mars landing spacecraft, the committee said. An independent review panel should be created by NASA and meet every three years to review new knowledge about the Martian environment and recommend updates, as needed, to Mars protection requirements.

The study was sponsored by NASA. The National Research Council is the principal operating arm of the National Academy of Sciences and the National Academy of Engineering. It is a private, nonprofit institution that provide science and technology advice under a congressional charter. A committee roster follows.

Copies of Preventing the Forward Contamination of Mars will be available this fall from the National Academies Press; tel. 202-334-3313 or 1-800-624-6242 or order on the Internet at Reporters may obtain a pre-publication copy from the Office of News and Public Information (contacts listed above).

[ This news release and report are available at ]

Division on Engineering and Physical Sciences
Space Studies Board

Committee on Preventing the Forward Contamination of Mars

Christopher F. Chyba (chair)
Professor of Astrophysics and International Affairs
Princeton University
Princeton, N.J.

Stephen Clifford
Staff Scientist
Lunar and Planetary Institute

Alan Delamere
Senior Engineer and Program Manager
Ball Aerospace and Technologies Corp. (retired)
Boulder, Colo.

Martin S. Favero
Scientific and Clinical Affairs
Advanced Sterilization Products
Johnson & Johnson
Irvine, Calif.

Eric J. Mathur
Vice President of Scientific Affairs
Diversa Corp.
San Diego

John Niehoff
Senior Research Engineer and Corporate Vice President
Science Applications International Corp.
Schaumburg, Ill.

Gain Gabriele Ori
International Research School of Planetary Science, and
Professor of Geology
Universita d'Annuzio
Pescara, Italy

David A. Paige
Associate Professor of Planetary Science
Department of Earth and Space Sciences University of California
Los Angeles

Ann Pearson
Assistant Professor of Biogeochemistry
Department of Earth and Planetary Sciences
Harvard University
Cambridge, Mass.

John C. Priscu
Professor of Ecology
Department of Land Resources and Environmental Sciences
Montana State University

Margaret Race
Visiting Fellow
Center for International Security and Cooperation
Stanford University, and
SETI Institute
Lafayette, Calif.

Mitchell Sogin
Josephine Bay Paul Center for Comparative Molecular Biology and Evolution
Marine Biological Laboratory
Woods Hole, Mass.

Cristina Takacs-Vesbach
Assistant Professor
Department of Biology
University of New Mexico


Pamela Whitney
Study Director