NASA Demonstrates Nuclear Fission System Capable Of Powering Future, Long-Term Exploration

NASA has big things in store in terms of future space exploration. Although the U.S. space agency recently pulled the plug on its robotic lunar Resource Prospector mission, it hasn't given up on the goal to send astronauts back to the moon. At the same time, a manned mission to Mars is in the cards for the 2030s.

Regardless of their destination, future space exploration missions will require an efficient and dependable energy source, especially during long-term ventures in outer space.

To make this happen, NASA and the National Nuclear Security Administration (NNSA) of the U.S. Department of Energy started working on a pioneering power system last year, known as the Kilopower project.

This enterprise aimed to build a safe and affordable nuclear space reactor that would provide enough energy for long-term manned space missions. Initiated in November, the project concluded this March and NASA is finally ready to announce the results.

According to a news release issued today, the Kilopower project was a major success. NASA and NNSA tested the nuclear fission system in a four-phase experiment dubbed KRUSTY (Kilopower Reactor Using Stirling Technology), which proved the space reactor is fully operational and capable of withstanding any hurdle.

The KRUSTY experiment, held at NASA's Glenn Research Center in Cleveland, revealed that the Kilopower system is capable of generating up to 10 kilowatts of electrical power continuously for at least a decade. According to NASA, four Kilopower units would be enough to provide sufficient electrical energy in order to establish a lunar or a Martian outpost.

"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," said Marc Gibson, lead Kilopower engineer at Glenn.

The nuclear fission system operates on a solid, cast uranium-235 reactor core, roughly the size of a paper towel roll, from which passive sodium heat pipes transfer heat to high-efficiency Stirling engines that convert it to electricity.

NASA expects that the Kilopower nuclear fission system will become a valuable asset in any future space exploration trips, especially manned or robotic missions to the moon. Since solar-powered energy sources would be short-lived during such a mission, given that lunar nights are equivalent to 14 days on Earth, having a nuclear energy source would be particularly beneficial to a lunar outpost, Gibson pointed out in the news release.

"Kilopower gives us the ability to do much higher power missions, and to explore the shadowed craters of the moon."
The KRUSTY demonstration put the Kilopower system through a series of four tests, culminating a 28-hour simulation of an actual space mission, that tested the full power of the nuclear reactor. The experiment also investigated how the system would fare in the event of technical malfunctions, such as power reduction, failed engines, and failed heat pipes.
Chief reactor designer David Poston, from the NNSA's Los Alamos National Laboratory, revealed that the Kilopower nuclear fission system proved to be stable and safe in all those circumstances.
"We threw everything we could at this reactor, in terms of nominal and off-normal operating scenarios and KRUSTY passed with flying colors."
The project team is currently in the process of developing mission concepts and taking additional risk reduction measures to prepare the Kilopower system for a possible future flight demonstration, NASA disclosed in the news release.