Nuclear-Challenged U.S. Turns to Europe to Meet NASA’s Plutonium needs DailyTech

Europe, a leader in nuclear power, has announced that it intends to lend its American counterparts a hand by making Pu-238 for NASA. David Southwood, ESA’s director of science and robotic exploration, in an interview with Spaceflight Now, states, “Our target is to have an independent capability, which may help our American friends.” Since the Pioneer and Voyager missions of the 1970s, NASA has been using the radioactive plutonium-238 (or Pu-238) isotope to power its deep space missions. The radioactive source has a very long half-life of 87.7 years. Over that period it slowly decays, releasing a steady stream of thermal energy in the process. That thermal energy is harvested by radioisotope thermoelectric generators (RTGs) in the probes to make power. Unfortunately, NASA’s plutonium stockpile has almost been exhausted, even as agency prepares its new Mars Space Laboratory which will require the isotope for power. There’s really no alternative currently for NASA, as the operational range of many of its missions place it well outside the spatial volume where the sun’s rays are strong enough to provide a decent level of solar power.