But what about powering space exploration? Most of our RTG fuel, the Platonium 238, was created a quarter century ago. NASA started producing more in 2013, but the worldwide shortage of RTG fuel is a perpetual constraint on space missions. And while our tiny supply of Platonium 238 can power exploration missions lasting decades anywhere in our solar system, the radioactive decay of Platonium really does not provide much power. Curiosity runs on 100 watts, rolling across the surface of Mars, taking photos, grinding samples, detecting neutrons, monitoring the atmosphere, and sending all this data back to us. Curiosity does all this on two incandescent light bulbs worth of power.