For the first time in 30 years, the United States has the capability to produce fuel for deep space missions.  Plutonium-238 is an isotope that produces thermal energy through radioactive decay.  This energy can be converted into electricity and used to power spacecraft systems for decades of flight.  Systems using this isotope include the Viking landers, the Voyager spacecraft, and more recent missions like the Mars Science Laboratory (Curiosity) and New Horizons. The Oak Ridge National Laboratory in Tennessee, run by the US Department of Energy, has produced 50 grams of the isotope, amounting to the size of a golf...