beyond clean-room assembly. If the probability for interacting with habitable regions exceeds 10–4 over a period of 103 years, then specific consideration must be given to whether the lack of complex and heterogeneous organic nutrients in aqueous environments of icy moons would preclude the propagation of any microbes that may have survived extreme irradiation and desiccation environments in transport. If the lack of nutrients indeed precludes propagation, then clean-room assembly is deemed sufficient; however, if the potential for propagation remains, then at least minimal planetary protection methods are required, and the final-decision question then considers whether heat treatment at 60°C for 5 hours would fail to eliminate all physiological groups that could potentially propagate on the target body. If so, then stringent planetary protection methods are required for the mission to proceed, or else the mission must either be reformulated or cancelled.

REFERENCES

1. J. Fragola, B. Putney, and J. Minarck III, An Evaluation of Containment Assurance Risk for Earth Entry Vehicle and Space Shuttle Sample Return, Earth Entry Vehicle Office, NASA Langley Research Center Hampton, Va., September 30, 2002.

2. J. Fragola, B. Putney, and J. Minarck III, Mars Sample Return Probabilistic Risk Assessment Final Report: An Evaluation of Containment Assurance Risk for Earth Entry Vehicle and Space Shuttle Sample Return, Contract No. 123-4119, NASA Langley Research Center, Hampton, Va.



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