Nuclear power sources: a key enabling technology for planetary exploration

Nuclear power sources for space (NPS) are, according to current physics knowledge, the only power source option for some classes of space missions. Europe has successfully used NPS exploration missions (e.g. Huygens lander on Titan and Ulysses spacecraft). Although some small-scale study and development efforts have been undertaken at the national level during the past 40 years, these did not go beyond study and early prototyping level. The present paper introduces the European situation with respect to the development and use of NPS.