Accomplishments and plans of SP-100 program

The SP-100 program is proceeding toward concept definitions for a space nuclear reactor which is safe and suitable for civilian and military applications. The selection of a specific design and demonstration of the base technologies was scheduled for the end of 1985, to be followed by engineering development and ground testing in 1986. The main current uses/users thus far anticipated are communications satellites, both military and civilian, radar (and possibly laser) surveillance and remote sensing systems, and manufacturing and other extensions of a space station growth scenario. The reactor will weigh no more than 3000 kg and must fit into the Orbiter bay with a payload and OTV. Three concepts are still under evaluation: a lithium-cooled reactor with thermoelectrics; an in-core thermionic system with pumped sodium-potassium coolant; and a configuration with a Stirling engine to convert reactor heat into electricity. If the engineering analyses and base tests are successful, it is expected that the flight application phase can be reached by 1991 at the latest