In the United States, it was decided to lift the ban on the use of radioisotope thermoelectric generators (RTGs), which can be used on space vehicles. The refusal of such facilities was dictated by insufficient volumes of fuel for the RTG-plutonium-238. According to the US Department of Energy, scientists were able to establish their own production of sufficient amounts of plutonium-238.
Plutonium-238 will be used in future NASA space missions as a source of nutrition. This will open up new prospects in the exploration of outer space, since it is the energy reserves that remain the weak link in the organization of space flights.
“Atomic batteries” will reduce the dependence of spacecraft from the Sun – they receive a significant part of the energy from the luminary. When traveling to the opposite side of the star, the energy collection efficiency is reduced, as it was during the expeditions to the surface of other planets, the same Mars. RTGs have already proved themselves, as they were installed on dozens of vehicles, including the automatic station New Horizons and the Voyager-1 probe.
The use of RTGs in the United States was under strict control due to a lack of fuel for them, as its own production of plutonium-238 was stopped in the US in 1988, it was purchased from the USSR. Some time ago, supplies stopped for technical reasons.
In 2015, the Oak Ridge National Laboratory and NASA began manufacturing metal for future space missions. The goal is to produce 1.5 kg of plutonium-238 annually until 2026. Now the aerospace agency has 35 kg of plutonium-238, a large part of which is reserved for the Mars 2020 mission.