Source: Space Flight Insider | Colin Skocik | June 18, 2019
Prospects of establishing a permanent human presence on the Moon have taken a step forward with the test of a system known as Kilopower, a lightweight fission reactor which could provide ten kilowatts of power for at least a decade.
Kilopower Reactor Using Stirling TechnologY (KRUSTY)—was developed by the Department of Energy’s National Nuclear Security Administration. Last week, the team won a Gears of Government President’s Award for their achievement.
Marc Gibson of NASA’s Glenn Research Center in Cleveland is one member of the team, and he explained how the system works.
“We designed the Kilopower reactors to generate anywhere from one to ten kilowatts of electrical power,” Gibson said. “This is enough to power several Earth-based homes…The nice thing about it is it’s lightweight, it’s compact, so we can put it pretty much anywhere we want to.”
A typical U.S. household drew an average of 1.2 kilowatts in 2016, according to the U.S. Energy Information Administration. According to Lee Mason, a principal technologist at NASA and another member of the team, “What we are striving to do is give space missions an option beyond RTGs, which generally provide a couple hundred watts or so.”
RTGs are radioisotope thermoelectric generators, which use the decay of plutonium-238 to generate electricity. They have been used for decades in NASA spacecraft, including many probes to the Moon, the Voyager and Pioneerspacecraft, and the Curiosity mission to Mars.
“The reason we need so much power in space is for things that we don’t normally need on Earth,” Gibson said, “creating oxygen or creating propellant for astronauts to leave the surface where they’re at—so there are several other factors that come into play when we’re putting humans on the surface of another planet for survival that you just need extra power for.”
The Kilopower reactor uses active fission to drive piston-based Stirling converters—far more efficient than the thermocouples used by RTGs. Modern industrial plants generate hundreds, even thousands of megawatts, but if the wattage produced by a single Kilopower reactor is not enough, several reactors can be used in a modular system.