Plutonium-238 supply project — Additional processing enabling power for future NASA missions

Abstract

For more than five decades, Radioisotope Power Systems (RPSs) have enabled space missions to operate in locations where the Sun's intensity is either too dim, obscured, or otherwise inadequate for solar power or other conventional power-generation technologies. The natural decay of the radioisotope plutonium-238 (238Pu) provides the heat source used by an RPS to generate electricity (as well as heat to keep key subsystems warm) for National Aeronautics and Space Administration (NASA) missions such as Voyagers 1 and 2, the Cassini mission to Saturn, the New Horizons flyby of Pluto, and the Mars Curiosity rover. The United States has not produced new 238Pu since the late 1980s. RPS-powered missions have continued since then using existing 238Pu inventory managed by the U.S. Department of Energy (DOE), including material purchased from Russia. NASA and DOE have determined that a new domestic supply is needed to ensure the continued availability of RPSs for future NASA missions. Using funding provided by NASA since 2011, DOE is currently executing a project to reestablish a 238Pu supply capability using its existing facilities and reactors. The project, known as the Plutonium-238 Supply Project (PSP) is led by the DOE Oak Ridge National Laboratory (ORNL). This paper will provide an overview of the PSP approach, its progress to date, and the potential benefits to NASA of missions that could be enabled by the new production of 238Pu.