Space Nuclear Reactor Integration Study

Over the past two years, a feasibility study was performed pertaining to the integration of Space Nuclear Reactor Power Sources (SNRPS's) with an Electro-Optical Surveillance System (EOSS) spacecraft. Phase One of the study showed that a 10 kWe SNRPS could begin to show significant mass savings for the EOSS satellite when compared to an equivalent solar power source. In addition, the SNRPS offered significantly reduced visibility, freedom from solar orientation, and compact packaging for launch. Phase Two of the study examined the impact of utilizing additional power from a SNRPS on the EOSS spacecraft and mission. Four main areas were addressed: electric propulsion (EP), survivability enhancements, spacecraft enhancements, and spacecraft design impacts. The study also outlined the requirements a SNRPS would have to meet to be considered as the power source of choice for a spacecraft designer. The mass and volume of nuclear power systems do not increase as quickly with power level as do the mass and volume of solar power systems. At power levels of 10 kWe, SNRPS's have an advantage over equivalent solar power sources with respect to mass and size; this advantage increases with increasing power levels. At power levels of about 25 kWe, a nuclear power system enables increased operational altitude, increased operational capabilities, and enhanced survivability. Accomplishing a similar mission with solar power is not feasible; accommodating battery charging and degradation over the life of the mission would require a solar power source capable of producing 44 kWe at the beginning of the mission (35 kWe at the end of the mission). Packaging and launching such a system is not feasible because of the mass and packaging constraints of launch vehicles projected to be available in the 2000-2005 timeframe. The main purpose of this paper is to present the results of Phase Two of the study. To provide appropriate background, however, this paper briefly discusses the results of Phase One; the results of Phase Two are then treated in more depth.