A History of Space Nuclear Power

07.19.06 | 1 min read | Text by Steven Aftergood

(updated below)

On January 19, 2006 NASA successfully launched the New Horizons spacecraft on a mission to Pluto. It will fly by the ninth planet on July 14, 2015 before proceeding into the Kuiper Belt.

New Horizons is powered by a radioisotope thermoelectric generator (RTG) fueled by plutonium-238. The natural heat of decay of the plutonium-238 fuel is converted to about 200 watts of electricity by means of thermoelectric cells.

“Since 1961, the United States has successfully flown 41 radioisotope thermoelectric generators (RTGs) and one reactor to provide power for 24 space systems,” reported Gary L. Bennett in a newly updated history of space nuclear power (pdf).

“The development and use of nuclear power in space has enabled the human race to extend its vision into regions that would not have been possible with non-nuclear power sources,” wrote Bennett, a former Energy Department and NASA official who devoted much of his career to the development of space nuclear power sources.

See “Space Nuclear Power: Opening the Final Frontier” by Gary L. Bennett, American Institute of Aeronautics and Astronautics paper number AIAA-2006-4191, presented at the 4th International Energy Conversion Engineering Conference, June 2006 (posted with the author’s permission).

Update: And see, relatedly, “Mission of Daring: The General-Purpose Heat Source Radioisotope Thermoelectric Generator” (pdf) by Gary L. Bennett and James J. Lombardo, et al, (AIAA-2006-4096, also presented at the 4th IECEC, June 2006.