Source: Space | Harrison Tasoff | December 14, 2017
NASA and the U.S. Department of Energy are collaborating to develop the next generation of nuclear generators, with a focus on crewed missions to Mars.
The Kilopower project, depicted in a new video from NASA,aims to produce a nuclear generator with greater efficiency and higher output than those currently in use.
Nuclear power has a long and successful history of use in space exploration. It powered the Pioneer 10 and 11 spacecraft that explored the solar system in the 1970s and continues to be used in technologies such as the Curiosity rover, which arrived on Mars in 2012. Nuclear fission provides a compact, reliable source of electricity, especially in situations where solar panels would be ineffective. [NASA to Test Fission Power for Future Mars Colony]
NASA has used so-called radioisotope thermoelectric generators (RTGs) for decades to convert heat from the natural decay of radioactive elements directly into electricity. This is what the Pioneers and Curiosity use. The decay causes a temperature difference across plates of two different kinds of metal — one connected to the reactor and the other to a radiator, which produces a voltage. This component, called a thermocouple, is commonly used in thermometers and temperature sensors. RTGs have the benefit of containing no moving parts, which could wear down on long missions, with no chance for maintenance or replacement.