Rolls-Royce unveils early-stage design for space nuclear reactor

diagram of a nuclear reactor
A rendering of Rolls-Royce's proposed space micro-nuclear power system. (Image credit: Rolls-Royce)

A new image shows a possible version of future space propulsion.

Nuclear fission systems, which harness the energy released in the splitting of atoms, could be used to power astronaut bases on the moon or Mars. Or they could help shorten the travel time to the Red Planet, which takes six to nine months to reach with current-generation propulsion systems.

Rolls-Royce could be a part of that ambitious spaceflight future. The venerable company released an early-stage design of a micro-nuclear reactor on Friday (Jan. 27), in the wake of a 2021 agreement with the United Kingdom Space Agency to study future nuclear power options in space exploration.

"Each uranium particle is encapsulated in multiple protective layers that act as a containment system, allowing it to withstand extreme conditions," Rolls-Royce tweeted in a brief description of the system.

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

Nuclear systems have long flown on robotic space missions. For example, radioisotope thermoelectric generators (RTGs) provide electricity for many probes, including NASA's Voyager 1 and Voyager 2 spacecraft, which are currently exploring interstellar space. Big NASA Mars rovers like Perseverance and Curiosity also use RTGs, though smaller rovers such as Spirit and Opportunity went with solar panels.

But RTGs are not fission reactors. Rather, they are nuclear batteries, converting to electricity the heat thrown off by the decay of radioactive material. Nuclear fission has yet to power a spacecraft off Earth, though that could change soon; for example, NASA and DARPA recently announced plans to build a nuclear thermal rocket by 2027.

Nuclear fusion — the power source of the sun and other stars, which flows from the merging of atoms — could also one day be part of humanity's spaceflight portfolio. That possible future is a long-term one, however; our species has yet to harness this power source here on Earth. (But U.S. scientists did announce a big breakthrough recently: a fusion experiment that produced more energy than it consumed.)

Speaking generally, some of the concerns of space fission or fusion power include safety for astronauts; portability, as more mass means a more expensive mission; and longevity in a harsh and rugged environment. 

But nuclear power is a staple of space exploration nonetheless, both in reality and in science fiction. The technology even helped fuel a joke in the 2015 movie "The Martian." In the film, astronaut Mark Watney (played by Matt Damon) — in search of warmth in an unheated rover and desperately digging up a reactor buried in regolith for safety reasons — said his Red Planet training manual had a section about surface operations labeled "Don't Dig Up The Big Box of Plutonium, Mark."

Elizabeth Howell is the co-author of "Why Am I Taller?" (ECW Press, 2022; with Canadian astronaut Dave Williams), a book about space medicine. Follow her on Twitter @howellspace. Follow us on Twitter @Spacedotcom or Facebook.

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Elizabeth Howell
Staff Writer, Spaceflight

Elizabeth Howell (she/her), Ph.D., is a staff writer in the spaceflight channel since 2022 covering diversity, education and gaming as well. She was contributing writer for for 10 years before joining full-time. Elizabeth's reporting includes multiple exclusives with the White House and Office of the Vice-President of the United States, an exclusive conversation with aspiring space tourist (and NSYNC bassist) Lance Bass, speaking several times with the International Space Station, witnessing five human spaceflight launches on two continents, flying parabolic, working inside a spacesuit, and participating in a simulated Mars mission. Her latest book, "Why Am I Taller?", is co-written with astronaut Dave Williams. Elizabeth holds a Ph.D. and M.Sc. in Space Studies from the University of North Dakota, a Bachelor of Journalism from Canada's Carleton University and a Bachelor of History from Canada's Athabasca University. Elizabeth is also a post-secondary instructor in communications and science at several institutions since 2015; her experience includes developing and teaching an astronomy course at Canada's Algonquin College (with Indigenous content as well) to more than 1,000 students since 2020. Elizabeth first got interested in space after watching the movie Apollo 13 in 1996, and still wants to be an astronaut someday. Mastodon:

  • steve_foston
    Well we may as well use Uranium/Plutonium for something useful like space travel rather than nuclear bombs, etc. Russia, Chine and the USA has plenty of material that it would be good to get rid of. We are coming up to the limits using chemical propellants in rockets if we really do want to explore the solar system build an interplanetary economy and 'Ad astra'. Interesting development that will be well engineered by Rolls Royce.
  • Benbenben
    There are actually numerous (around 30) fission based reactors in satellites in orbit around the Earth.