Nasa’s mini nuclear reactor passes test to withstand space flight
Image credit: nasa
Nasa’s miniature nuclear fission reactor designed for long-distance space flight has “passed with flying colours” a series of tests to ensure it can withstand the rigours of space travel.
The power system is seen as an essential component for future long-duration crewed missions to the Moon, Mars and destinations beyond.
The Kilopower Reactor Using Stirling Technology - aka Krusty - is a small, lightweight, fission-power system capable of providing up to 10 kilowatts of electrical power, enough to run several average households, continuously for at least 10 years.
Four Kilopower units would provide enough power to establish an outpost on a foreign space body.
According to Marc Gibson, lead Kilopower engineer, the system is ideal for the Moon, where power generation from sunlight is difficult because lunar nights are equivalent to 14 days on Earth.
“Kilopower gives us the ability to do much higher power missions and to explore the shadowed craters of the Moon,” said Gibson.
“When we start sending astronauts for long stays on the Moon and to other planets, that’s going to require a new class of power that we’ve never needed before.”
The prototype power system uses a solid cast uranium-235 reactor core, about the size of a paper towel roll. Passive sodium heat pipes transfer reactor heat to high-efficiency Stirling engines, which convert the heat to electricity.
According to chief reactor designer David Poston the system was recently tested in Nevada in order to demonstrate that it can both create electricity with fission power and show that it is stable and safe no matter what environment it encounters.
While the team already conducted some tests on the reactor in January, this experiment took a far more rigorous approach by emulating some of the environments in which the reactor may need to operate during space flight.
“We threw everything we could at this reactor, in terms of nominal and off-normal operating scenarios and Krusty passed with flying colours,” said Poston.
The Kilopower team conducted the experiment in four phases. The first two phases, conducted without power, confirmed that each component of the system behaved as expected.
During the third phase, the team increased power to heat the core incrementally before moving on to the final phase. The experiment culminated with a 28-hour, full-power test that simulated a mission, including reactor startup, ramp to full power, steady operation and shutdown.
Throughout the experiment, the team simulated power reduction, failed engines and failed heat pipes, showing that the system could continue to operate and successfully handle multiple failures.
“We put the system through its paces,” said Gibson. “We understand the reactor very well and this test proved that the system works the way we designed it to work. No matter what environment we expose it to, the reactor performs very well.”
The Kilopower project is developing mission concepts and performing additional risk-reduction activities to prepare for a possible future flight demonstration.
Nasa is due to launch its next Mars probe at the weekend, which has a mission to discover more information about the internal workings of the Red Planet.