Rolls-Royce to Develop Nuclear Power for a Moon Base

In what must be an unusual Sunday, press release, the U.K. Space Agency and Rolls-Royce announced the agency has decided to continue funding Rolls-Royce's project to create a small nuclear-powered reactor that could serve as a long-term energy source for lunar bases. 

The new boost to Rolls-Royce’s research pot follows a previous $303,495 (£249,000) study funded by the U.K. Space Agency in 2022. With the new funds, the company hopes to have a demonstration model for a modular micro-reactor ready to deliver to the moon by 2029.

The article grabbed my attention simply because it mentioned Rolls-Royce and I had no idea that the luxury car company had anything to do with small nuclear reactor design or production. The press release goes on to say:

Relatively small and lightweight compared to other power systems, a nuclear micro-reactor could enable continuous power regardless of location, available sunlight, and other environmental conditions.

Rolls-Royce will be working alongside a variety of collaborators including the University of Oxford, University of Bangor, University of Brighton, University of Sheffield’s Advanced Manufacturing Research Centre (AMRC) and Nuclear AMRC. The funding means Rolls-Royce can further strengthen its knowledge of these complex systems, with a focus on three key features of the Micro-Reactor; the fuel used to generate heat, the method of heat transfer and technology to convert that heat into electricity.

Artist's illustration of a Rolls-Royce microreactor on the moon. (Image credit: Rolls-Royce Holdings)

The quote above said the work will focus on the "three key features of the Micro-Reactor; the fuel used to generate heat, the method of heat transfer and technology to convert that heat into electricity," and that implies they have barely scratched the surface of what they need to know to successfully run a small reactor in that environment.  As you undoubtedly already know, the majority of near-Earth and inner solar system missions depend on solar power for their energy; photovoltaic cells like you can put on your roof.  Probes to the outer planets, such as the Voyager, Cassini and other probes, tended to run instead on small Radioisotope Thermoelectric Generators or RTGs.  

RTGs aren't conventional nuclear reactors by any means, but aren't dependent on the diminishing sunlight as the probes went ever farther from the sun.  The RTG uses the difference in heat from the nuclear-isotope (the isotope used varied with the mission) and the cold of deep space to drive a thermoelectric generator; something not likely to work baking in the daytime temperatures on the surface of the moon.  A small thermoelectric generator can be a hobbyist toy, and they're cheap and easy to play with. 

It sounds to me like what Rolls-Royce is looking to develop is something like the KRUSTY system we talked about nearly five years ago.  KRUSTY was the acronym for Kilopower Reactor Using Stirling TechnologY that used nuclear fuel to produce heat, Stirling engines (another hobbyist favorite) to turn that heat into mechanical energy and then convert that mechanical energy into electrical energy.  

Conceptual illustration of a complete lunar base, powered by the reactors visible in the foreground and middle distance.  (Image credit: Rolls-Royce Holdings) 

Closing words to the UK Department of Science, Innovation and Technology:

"Partnerships like this, between British industry, the U.K. Space Agency and government, are helping to create jobs across our £16 billion space tech sector and help ensure the U.K. continues to be a major force in frontier science," George Freeman, Minister of State at the Department of Science, Innovation and Technology, said in the March 17 press release.