Radioisotope Power System for the Curiosity Rover at Kennedy Space Center.
Credit: NASA


An automation process is geared to resolving a key bottleneck in boosting the annual production of Pu-238 toward NASA’s goal of 1.5 kilograms of Pu-238 per year by 2025.

Oak Ridge National Laboratory in eastern Tennessee, near Knoxville, is automating the production of neptunium oxide-aluminum pellets.


Pu-238 provides a constant heat source through radioactive decay, a process that has powered spacecraft such as NASA’s New Horizons mission to Pluto and beyond, the Cassini mission to Saturn and the Curiosity Mars Rover.

Nuclear power system is shown in this Curiosity Navcam Left A photo taken on Sol 2297, January 22, 2019.
Credit: NASA/JPL-Caltech

Upping yearly production

“Automating part of the Pu-238 production process is helping push annual production from 50 grams to 400 grams, moving closer to NASA’s goal of 1.5 kilograms per year by 2025,” said ORNL’s Bob Wham.

Artist’s concept of the nuclear powered New Horizons spacecraft encountering Pluto and its largest moon, Charon (foreground) in July 2015.
Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Steve Gribben/Alex Parker

Wham adds that the automation tactic is expected to increase the output of pressed pellets from 80 to 275 per week.

Oak Ridge National Laboratory scientists have automated part of the process of producing plutonium-238, which is used by NASA to fuel deep space exploration. Credit: Genevieve Martin and Jenny Woodbery/Oak Ridge National Laboratory, U.S. Dept. of Energy



Once the pellets are pressed and enclosed in aluminum tubing, they are irradiated at ORNL’s High Flux Isotope Reactor and chemically processed into Pu-238 at the Radiochemical Engineering Development Center.

In 2012, NASA reached an agreement with the Department of Energy to restart production of Pu-238, and ORNL was selected to lead the project.





Go to this ORNL video at:

as well as the video on New Horizons below:

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