Radioisotope Electric Propulsion (REP): A Near-Term Nuclear Propulsion System

Abstract

Studies over the last decade have shown Radioisotope-based Nuclear Electric Propulsion (NEP) to be enhancing and, in some cases, enabling for many potential science missions. Also known as Radioisotope Electric Propulsion (REP), the technology offers the performance advantages of traditional fission-based NEP (i.e., high specific impulse (Isp) electric propulsion at large distances from the Sun), but with much smaller, affordable spacecraft. Future use of REP requires development of radioisotope power sources with system specific powers well above that of current systems. The U.S. Department of Energy (DOE) and NASA are currently developing the Advanced Stirling Radioisotope Generator (ASRG) Engineering Unit, which is culminating in flight qualification-level and extended life testing by the end of 2008. This advancement, along with recent work on small ion thrusters and lifetime extension technology for Hall thrusters, could enable missions using REP sometime during the next decade.