By David Szondy
December 10, 2023
Mock-up of the Rolls-Royce lunar micro-reactor/Rolls-Royce
Rolls-Royce gave us a glimpse of the nuclear future of next-generation spacecraft and Moon bases when it unveiled a mock-up of its Space Micro-Reactor Concept Model at the UK Space Conference in Belfast, which ran between November 21 to 31, 2023.
With any number of nations and private companies committed to launching an increasing number of crewed and uncrewed missions to the Moon, as well as extending activities into deep space, finding a reliable source of power beyond solar panels has become an imperative.
In addition, chemical rockets have been operating near their theoretical limits since the first V2 tests during the Second World War. As humanity ventures farther into deep space and with the increasing need to police and maintain satellites in Earth orbit, a more efficient propulsion system is required.
Under a UK Space Agency-funded £2.9-million (US$3.6-million) program, Rolls-Royce has been working on a new micro-reactor to address these needs. This small, advanced reactor, which is scheduled for a demonstration on the Moon early next decade, is designed to provide future bases with the power needed to not only take on very ambitious tasks, but also to heat the bases so they can survive the extremely cold lunar night.
In addition, the new reactor is designed to act as a power source for electric and other propulsion systems that will extend mission ranges to the outer solar system and beyond, and to allow maintenance and patrol spacecraft to move between Earth orbits with much greater speed and flexibility than is possible today.
This is all well and good, but up until now the public and industry have had only concept art of the micro-reactor to go on. That is, until Rolls-Royce revealed its mock up of the demonstration reactor that will seek answers as to how to generate heat, how to transfer that heat, and how to convert it into electricity.
The mock up is a cutaway that shows the basic design of the micro-reactor, including what looks like either fuel rods, which is unlikely, or part of the heat transfer system. According to the company, the device is a fission reactor operating on the same principle as commercial power reactors on Earth, though using an advanced design relying on TRi-structural ISOtropic (TRISO) particle fuel that is a variant of pebble bed reactor fuel, which replaces rods with billiard-ball-sized fuel globes consisting of enriched uranium, carbon and oxygen. The uranium core is sealed inside layers of carbon and ceramics. This is both inherently safer than fuel rods and allows for a simpler gas-cooling system.
“The funding from the UK Space Agency has allowed the Rolls-Royce Micro-Reactor program to work collaboratively with the UK Space Agency, UK academic institutions and industry partners to showcase the best of UK innovation and knowledge in space,” said Abi Clayton, Director of Future Programmes for Rolls-Royce. “This funding has enabled crucial research and development of technologies that bring us closer to making the Micro-Reactor a reality. Our Space Micro-Reactor Concept Model allows us to demonstrate how this technology will bring immense benefits for both space and Earth.
“Micro-Reactor technology will deliver the capability to support commercial and defense use cases alongside providing a solution to decarbonize industry and provide clean, safe and reliable energy.”