DETERMINATION OF ACCEPTABLE RISK

The committee believes that the BR can be a tool to support both identification and management of risks such that each risk reaches an “acceptable” status for the relevant mission by the intended launch time for that mission. Several potentially useful risk management systems currently exist (e.g., NASA Continuous Risk Management Program [NASA, 1999], U.S. Navy Virginia Class Submarine [Kulez, 2003]). The committee does not recommend a specific implementation system but observes that a roadmap that supports risk management will have to contain elements that support operations in addition to those that point to needs for further research.

In this regard, although research in most fields may continue ad infinitum, the BR should attempt to identify “what is good enough” for the launch of a given category of mission. Researchers in virtually all fields are reluctant to declare total success, since this would be tantamount to forfeiting future funding. In the conduct of exploration, leaders cannot wait until every detail is resolved definitively, but only until the collective risk is mitigated adequately or otherwise reduced to permit a high enough level of optimism to justify mission initiation. This by no means suggests that research in a field should be terminated when sufficient progress has been made for launch, only that the mission should be “cleared” and further research dissociated from the operational aspects of the mission.

The presentation of information relative to risk management will have to be linked to the Design Reference Missions. The three different missions under consideration—1 year aboard the International Space Station (ISS), 1 month on the lunar surface, and a 30-month mission to Mars and back—will have different detailed risk management requirements in each risk category. A risk currently considered unacceptable for the Mars mission may very well be acceptable for the ISS mission. The fact that four Russian individuals (Titov, Manarov, Polyakov, and Avdeyev) have already spent a continuous year or more each in low Earth orbit suggests that the ISS mission category should be rephrased to either (1) identify additional detailed (scientific) mission objectives over and above mere survival for a year in orbit or (2) call for qualifying humans for routine and/or repetitive mission durations of 1 year in the ISS.



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