anticipated that the first sample return from Mars will unlock all of the planet’s secrets. Orbital observations have shown that Mars’s geologic and climatic history is best exposed in widely separated, isolated locations, and a complete picture of martian history is unlikely to be obtained from samples collected at a single location. Instead, the first sample return should be seen as a trailblazer for future sample-return missions, and it should be used to develop the key technologies, procedures, and infrastructure necessary to embark on a future program in which samples are returned from many locations on the planet. COMPLEX estimates that roughly 10 sample-return missions, necessarily executed over a protracted period of time—perhaps three or four decades to as much as a century—may be required to learn the most important things researchers want to know about Mars. A protracted schedule of exploration will allow time for the information gained by each mission to be digested and fed into the planning of the next mission, and it will permit substantial redesign of the spacecraft and sampling system between missions.

Recommendation. It should not be anticipated that a few (two to three) Mars sample-return missions will serve the need for samples from that planet. No single site or small number of sites on Mars will answer all of the important questions about the planet, and in any case, the earliest sample-return missions will be in large part technology-development missions. Something like 10 sample-return missions, spread over a substantial period of time, may be required to answer the important questions about Mars.

Considerations of planetary protection dictate that stringent measures be taken during a sample-return mission to prevent biological contamination of either Earth or Mars. One essential measure is the construction of a quarantine facility to receive and contain samples when they arrive on Earth. COMPLEX reiterates the conclusion of its recent report on the design and operation of a Mars Quarantine Facility—that a long lead time is required to prepare such a facility.a On the basis of prior experience with facilities of this type, COMPLEX estimated that 7 years will be required to design, construct, and staff the facility. To this period must be added the time needed to clear an environmental impact statement and to carry out several reconnaissance studies that are needed to inform the design and operation of the facility.b The aggregate of time required may strain the schedule even of a 2011 launch. The message is plain: Preparations for sample return should not be delayed any longer than they already have been (see Chapter 12).

Recommendation. Scientific research and design studies that must precede the design and construction of the Mars Quarantine Facility should begin immediately. Decisions should be made immediately about the siting and management of the facility. Design and construction of the facility should begin at the earliest possible time.

Chapter 7 elaborates on this recommendation, reiterating the conclusions of COMPLEX’s recent report on the quarantine of martian samples. In summary, these conclusions are as follows:

  • The Mars Quarantine Facility in which Mars samples will be processed, stored, and released for scientific study, and in which a very limited range of studies will be carried out, must be designed, built, and certified.

  • Research must be initiated on several outstanding questions that will affect the design of the Mars Quaran-tine Facility (e.g., combining biological isolation with clean-room conditions; establishing the efficacy and detrimental effects of sterilization techniques).

  • The study of life in extreme environments on Earth, which can aid in the design of life-detection tests, should be supported, as is already being done. In general, research areas that improve the sensitivity of life-detection techniques must be supported, and a life-detection protocol to be implemented and tested in the Mars Quarantine Facility must be developed.

  • Techniques must be developed for the collection, packaging, and return of samples.


Space Studies Board, National Research Council, The Quarantine and Certification of Martian Samples, National Academy Press, Wash-ington, D.C., 2002.


For more details, see Space Studies Board, National Research Council, The Quarantine and Certification of Martian Samples, National Academy Press, Washington, D.C., 2002.

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