Nuclear Auxiliary Power - Watts to Megawatts with SNAP

Full utilization of the capability of advanced booster systems can only be realized if adequate auxiliary power units are integrated into the payload vehicle. Nuclear power units offer unique advantages for space application, - included are: compactness, light-weight, long reliable life, elimination of need for secondary batteries and sun orientation requirements, growth potential from hundreds of watts to megawatt range, and development of qualified units on a time scale that is consistent with present expected payload growth capability. Studies have shown solar cells and nuclear isotope auxiliary power systems have application in missions with power requirements up to a few hundred watts, solar dynamic and nuclear reactor systems are competitive for the sub-kilowatt to few kilowatt level; however, beyond this range compact reactor systems are the only feasible way of obtaining the power needs for advanced missions (Fig. 1). Compact reactors and power conversion equipment for space application have been under development for a number of years under AEC, NASA, and DOD sponsorship, where today three SNAP (Systems for Nuclear Auxiliary Power) reactor projects are now progranmed for early orbital flight testing. These are the 500 watt SNAP 10A, the 3Kw SNAP 2, and 30/60 Kw SNAP 8 systems. Advanced space systems capable of producing hundreds of kilowatts with extension into the megawatt range with less than 5 lbs/kw specific weight are now under study.