Space Power Systems for the 21 st Century

Space power systems upon entering the 21 century are primarily based upon photovoltaic solar arraybattery power for most earth and planetary orbiting satellites and smaller scale systems for planetary landers. Nuclear powered systems using radioisotopes have been reserved for outer planetary science and exploration with space nuclear reactors not being launched since the early 1980s. The recent interest in nuclear space power systems for very high power missions have relegated the development of advanced solar power systems to the study mode. However, these concepts are now emerging for more detailed examination. We review the current concepts for advanced high power solar systems and compare to proposed space nuclear power systems that have been under consideration. We identify the technical and feasibility issues for future development and project other relevant emerging technologies which may be developed in the latter part of the 21 century.