FAS

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.

publications
See all publications
Emerging Technology
Blog
Team Science needs Teamwork: Universities should get in on the ground floor in shaping the vision for new NSF Tech Labs

At a time when universities are already facing intense pressure to re-envision their role in the S&T ecosystem, we encourage NSF to ensure that the ambitious research acceleration remains compatible with their expertise.

12.12.25 | 4 min read
read more
Emerging Technology
Blog
NSF Plans to Supercharge FRO-style Independent Labs. We Spoke with the Scientists Who First Proposed the Idea.

FAS CEO Daniel Correa recently spoke with Adam Marblestone and Sam Rodriques, former FAS fellows who developed the idea for FROs and advocated for their use in a 2020 policy memo.

12.12.25 | 10 min read
read more
Government Capacity
Blog
Demystifying the New President’s Management Agenda

In a year when management issues like human capital, IT modernization, and improper payments have received greater attention from the public, examining this PMA tells us a lot about where the Administration’s policy is going to be focused through its last three years.

12.11.25 | 20 min read
read more
Government Capacity
day one project
Policy Memo
A Digital Public Infrastructure Act Should Be America’s Next Public Works Project

Congress must enact a Digital Public Infrastructure Act, a recognition that the government’s most fundamental responsibility in the digital era is to provide a solid, trustworthy foundation upon which people, businesses, and communities can build.

12.08.25 | 18 min read
read more