Space Fuel: Plutonium-238 Created After 30-Year Wait

Scientists have produced a powder of plutonium-238 for the first time in nearly 30 years in the United States, a milestone that they say sets the country on a path toward powering NASA's deep-space exploration and other missions. Plutonium-238 (Pu-238) is a radioactive element, and as it decays, or breaks down into uranium-234, it releases heat. During the Cold War, the Savannah River Plant in South Carolina was pumping out Pu-238.