[10] The Systems Nuclear Auxiliary Power Program reactor was specifically developed for satellite use in the 1950s and early 1960s under the supervision of the U.S. Atomic Energy Commission.

[11][12] The Systems for Nuclear Auxiliary Power (SNAP) program developed as a result of Project Feedback, a Rand Corporation study of reconnaissance satellites completed in 1954.

The other project used nuclear reactors to generate energy, and was developed by the Atomics International Division of North American Aviation.

[14]: 5, 7 Most of the systems development and reactor testing was conducted at the Santa Susana Field Laboratory, Ventura County, California using a number of specialized facilities.

The reflectors were composed of a layer of beryllium, which would reflect neutrons, thus allowing the reactor to begin and maintain the fission process.

The NaK was circulated through the core and thermoelectric converters by a liquid metal direct current conduction-type pump.

The thermoelectric converters (identified as the long white "apron") are doped silicon germanium materials, thermally coupled, but electrically isolated from the NaK heat transfer medium.

[18] SNAP-10A was launched from Vandenberg Air Force Base by an ATLAS Agena D rocket on 3 April 1965 into a low Earth orbit altitude of approx.

The program was established to evaluate the nuclear hazards associated with the construction, launch, operation and disposal of SNAP systems and to develop designs to assure their radiological safety.

[27] The SNAPTRAN-3 destructive experiment, on 1 April 1964, simulated a rocket crash into the ocean, purposely sending radioactive debris across the Idaho desert.

The testing and development involving radioactive materials caused environmental contamination at the former Atomics International Santa Susana Field Laboratory (SSFL) facilities.