National Research Council. Radioisotope Power Systems: An Imperative for Maintaining U.S. Leadership in Space Exploration

National Academies Press, Washington, 2009, 53 pages, ISBN: 0309138574National Research Council, Radioisotope Power Systems CommitteeSpacecraft require electrical energy. This energy must be available in the outer reaches of the solar system where sunlight is very faint. It must be available through lunar nights that last for 14 days, through long periods of dark and cold at the higher latitudes on Mars, and in high-radiation fields such as those around Jupiter. Radioisotope power systems (RPSs) are the only available power source that can operate unconstrained in these environments for the long periods of time needed to accomplish many missions, and plutonium-238 (238Pu) is the only practical isotope for fueling them.Radioisotope power systems (RPSs) such as radioisotope thermoelectric generators provide electrical power for spacecraft and planetary probes that cannot rely on solar energy. To support the continued availability of the RPSs required to power NASA space missions, Congress and NASA requested that the National Research Council (NRC) undertake a study of RPS technologies and systems.The NRC formed the Radioisotope Power Systems Committee to produce this report in response to House Report 110-240 on the Commerce, Justice, Science, and Related Agencies Appropriations Bill, 2008. This report assesses the technical readiness and programmatic balance of NASA’s RPS technology portfolio in terms of its ability to support NASA’s near- and long-term mission plans. In addition, the report discusses related infrastructure, the effectiveness of other federal agencies involved in relevant research and development, and strategies for reestablishing domestic production of 238Pu, which serves as the fuel for RPSs. To put the discussion of RPSs in context, the report includes some information regarding other options (i.e., solar power and space nuclear power reactors), but a detailed assessment of these alternatives is beyond the scope of the statement of task. A complete copy of the statement of task appears in Appendix A.