SP-100 (Space reactor Prototype) was a U.S. research program for

nuclear fission reactor A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion. Heat from n ...

s usable as small fission power systems for spacecraft. It was started in 1983 by

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...

, the

US Department of Energy The United States Department of Energy (DOE) is an executive department of the U.S. federal government that oversees U.S. national energy policy and manages the research and development of nuclear power and nuclear weapons in the United State ...

and other agencies.''SP-100, the US Space Nuclear Reactor Power Program,'' Technical information report. Available a
Energy Citations Database
/ref> A reactor was developed with

heat pipes A heat pipe is a heat-transfer device that employs phase transition to transfer heat between two solid interfaces. At the hot interface of a heat pipe, a volatile liquid in contact with a thermally conductive solid surface turns into a vapor ...

transporting the heat to

thermoelectric generator A thermoelectric generator (TEG), also called a Seebeck generator, is a solid state device that converts heat flux (temperature differences) directly into electrical energy through a phenomenon called the ''Seebeck effect'' (a form of thermoele ...

s. It was cooled with

lithium Lithium (from el, λίθος, lithos, lit=stone) is a chemical element with the symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard conditions, it is the least dense metal and the least dense solid el ...

. The project never advanced to flight hardware and was terminated in 1994.

References

Nuclear power in space {{US-spacecraft-stub

See also

References