Radioisotope power systems (RPS) are a critical technology to provide electricity for space missions. RPS produce electrical power by converting the heat generated by the natural radioactive decay of Plutonium-238 to electricity. They have been in use by the United States for over 50 years and NASA missions have utilized RPS to explore planets, moons, and interstellar space. This exploration resulted in changes to our understanding of our Solar System and our place within it., as well as improve life on Earth.

Despite their critical role in the U.S. space program, little is known about RPS technology outside NASA and some of their contractors. This report addresses that situation by examining current and future RPS technology, missions they are used for, Plutonium processing technologies, U.S. government agencies and laboratories involved producing RPS and processing Plutonium, RPS related budgets and private companies working in this field.

The world is entering a new era in Space where there will be more advances in the next few decades than throughout human history. RPS will be needed for these future missions (e.g. Lunar Gateway, Mars 2020) just like they have been in the past (e.g. Voyager 2, launched in 1977 and now sending signals back to earth from interstellar space).

Key Words: radioisotope power systems, product families, future RPS, NASA roles and responsibilities, space mission types, U.S. Department of Energy, Plutonium-238, RPS program, acquiring flight systems, Plutonium-238 supply project, constant rate production strategy, RPS funding, Plutonium-238 production, fundamental research, RPS selection, technology roadmap MMRTG, costs, RPS demand, advanced stirling radioisotope generators, dynamic RPS, Skutterudite, eMMRTG, modular RPS, solar technology, Pu-238 synthesis, PU-238 production, neptunium, production equipment, testing, chemical processing, staffing, target irradiation, radioisotope thermoelectric generators, GPHS modules, technology readiness levels, system considerations, NASA/DOE agreements, nuclear safety, Savannah River, process scale-up, production automation, nuclear reactors, dynamic power convertors, atmospheric compositions, temperature limits, Infinia Technology Corp, American Superconductor, Creare LL, Northrop Grumman Aerospace Systems, Sunpower Inc., Idaho National Laboratory, Los Alamos National Laboratory, National Aeronautics and Space Administration, Glenn Research Center, NASA priority goals, NASA planetary science budget.

This report was prepared by a senior American analyst working for a United States-based company. The report includes 56 figures and 25 tables.