Officials said the project has restored a domestic capability for producing Pu-238 for the first time in almost 30 years.

Idaho National Laboratory provides the inventory of neptunium-237 to ORNL, which fabricates the material - mixed with aluminum - into targets.

The agency has been funding the production of Pu-238 for roughly two years now, putting around $15 million into DOE's Office of Nuclear Energy's efforts each year.

According to the CS Monitor today, On Tuesday, that all changed. Fifty grams isn't much, but this is the first time the substance has been made in the country since the Savannah River Plant in SC stopped making it in the late 1980s.

The reason why NASA is running low on plutonium-238 is because of the nuclear disarmament movement in 1988, even though plutonium-238 is not a suitable source of fuel for nuclear weapons. Meanwhile, the remaining neptunium is recycled to create more plutonium.

ORNL and the Department of Energy, which issued separate announcements, said the infrastructure is now in place to provide a steady and growing supply of plutonium-238 for future space missions. NASA said it has 35 kg of plutonium-238, of which 17 kg is for spacecrafts. They use the High Flux Isotope Reactor, a DOE Office of Science User Facility at ORNL, to irradiate the pellets, creating neptunium-238, which quickly decays and becomes plutonium-238.

"Radioisotope power systems are a key tool to power the next generation of planetary orbiters, landers and rovers in our quest to unravel the mysteries of the universe", he said. That's just enough to last into the middle 2020s, powering just two or three proposed missions. And, in the statement, the DoE said that it hopes to scale up the operation to produce an average of 1.5 kilograms of plutonium in the coming years. Currently, about 35 kg worth are available for NASA missions.

"The supply of Pu-238 for RPS (Radioistope Power Systems) is both expensive and scarce", according to a "Nuclear Power Assessment Study" that was released in June, "so its efficient use and stewardship remain central challenges for NASA and DOE". This radioactive material produces heat when it starts decaying.

50 grams isn't, by any stretch, a substantial amount of the element, considering that the Mars rover for NASA's 2020 mission requires four kilograms.

Plutonium-238 is a radioactive isotope that produces heat as it decays, and the new sample is in the same oxide power form used to manufacture heat sources for power systems, including those used in spacecraft instruments, they explained.

The next NASA mission planning to use an MMRTG is the Mars 2020 rover, due to be launched as part of NASA's Journey to Mars, to seek signs of past life on the Red Planet, test technology for human exploration, and gather samples of rocks and soil that could be returned to Earth in the future.

Wham established that the production of Pu-238 was shown that the process is working, which would lead to the next phase of the mission.