Overview on Space Nuclear Systems

Abstract

Nuclear power sources have enabled or enhanced some of the most challenging and exciting space missions ever conducted. Since 1961, 47 radioisotope thermoelectric generators and 36 space nuclear reactors were successfully flown to provide power for 62 space systems. Yet, the future of nuclear technology for space exploration promises even more remarkable journeys and more amazing discoveries. Space fission nuclear systems can be divided in radioisotope power generators, nuclear thermal propulsion, nuclear electric propulsion and fission surface power technologies. Space radioisotope power systems use radioisotope decay to generate heat and electricity for space missions. For the last fifty-four years, radioisotope thermoelectric generators have provided safe, reliable electric power for space missions where solar power is not feasible. The new advanced sterling radioisotope generators are sought to do an even more efficient job on heat and electricity generation for future space missions. But future space missions will need increased power for propulsion and for surface power applications to support both robotic and human space exploration missions. Nuclear thermal propulsion and nuclear electric propulsion are the most technically mature, advanced propulsion systems that can enable a rapid access to different regions of interest throughout the solar system. The latter is possible by its ability to provide a step increase above what is feasible using a traditional chemical rocket system. Nuclear fission-based power systems are the best suited power sources for surface missions requiring high power in difficult environments where sunlight is limited and reliability is paramount. An overlook of such technologies and activities is presented.