Nuclear power on the moon: NASA wraps up 1st phase of ambitious reactor project

NASA is wrapping up the design phase of a project to develop concepts for a small, electricity-generating nuclear fission reactor for use on the moon.

The Fission Surface Power Project aims to develop safe, clean and reliable energy sources on the moon, where each nighttime lasts around 14.5 Earth days. Such a system could play a big role in the agency's Artemis program for lunar exploration.

NASA and the U.S. Department of Energy announced contracts to three companies — Lockheed Martin, Westinghouse and IX (a joint venture of Intuitive Machines and X-Energy) — for the initial phase back in 2022. 

Related: NASA funds nuclear probes for icy moons, huge new space telescopes and other far-out tech ideas 

The trio were tasked with submitting an initial design for a reactor and subsystems, estimated costs and a development schedule that could pave the way for powering a sustained human presence on the lunar surface for at least 10 years.

"The lunar night is challenging from a technical perspective, so having a source of power such as this nuclear reactor, which operates independent of the sun, is an enabling option for long-term exploration and science efforts on the moon," Trudy Kortes, program director for technology demonstration missions within NASA's Space Technology Mission Directorate, said in a Jan. 31 statement.

A reactor could be especially useful at the lunar south pole, where permanently shadowed regions are thought to have trapped water ice and other volatiles.

NASA next plans to extend Phase 1 contracts to refine the project's direction for Phase 2, which involves final reactor design for a lunar demonstration. Open solicitation for Phase 2 is expected to open in 2025.

"We're getting a lot of information from the three partners," said Lindsay Kaldon, Fission Surface Power project manager at NASA's Glenn Research Center in Cleveland. "We'll have to take some time to process it all and see what makes sense going into Phase 2 and levy the best out of Phase 1 to set requirements to design a lower-risk system moving forward."

After Phase 2, the target date for delivering a reactor to the launch pad is in the early 2030s, NASA stated.

The agency set requirements for a 40-kilowatt reactor that uses low-enriched uranium and weighs no more than 13,200 pounds (6,000 kilograms). Beyond certain constraints, the agency allowed for flexibility, allowing the companies to bring creative and diverse approaches for technical review. 

In the U.S., 40 kW can, on average, provide electrical power for 33 households, according to NASA.

The reactor plan is one of a number of new nuclear plans for space, including launching a nuclear-powered spacecraft, named DRACO, by early 2026.

NASA also recently awarded contracts for developing more efficient Brayton power converters, which are essential for converting thermal power from nuclear fission into electricity, to Rolls Royce North American Technologies, Brayton Energy and General Electric.