The reactor could keep the lights on during long-duration missions far from Earth.
NASA and the U.S. Department of Energy say they have successfully tested a new type of nuclear reactor that could one day provide juice to colonies on other worlds. The reactor can power several homes and appears able to operate in harsh environments.
Getting electricity in space is always a problem. Close to Earth, satellites and astronauts can use solar panels. But farther out, the sun's light dims, making it exponentially harder to get the power needed to run communications, scientific instruments and, in the case of astronauts, life support.
The best solution is good old-fashioned nuclear power. Nukes have fueled everything from NASA's Pluto probe to the Curiosity rover on Mars. Nuclear power sources are durable, and they can last a long time. The two Voyager spacecraft, launched in 1977, are still phoning home using power from a a few pounds of plutonium they carry with them.