Building Nuclear Power in the U.S. Is Tough. NASA Wants to Do It on the Moon.
So do China and Russia. Here’s what you need to know about America’s new lunar-energy race
- NASA is fast-tracking efforts to land a 100-kilowatt nuclear reactor on the moon by late 2029, aiming to establish a lasting presence.
- The lunar reactor faces challenges like lack of atmosphere for cooling and the need for heavy radiation shielding.
- Launching a reactor involves safety concerns, regulatory gaps and liability issues.
Call it a nuclear moonshot: The U.S. aims to deliver a reactor to the lunar surface and beat a push by China and Russia to do the same.
In August, NASA Acting Administrator Sean Duffy directed the agency to fast-track an effort to land a reactor on the moon by late 2029. The agency wants a 100-kilowatt system, about enough to power a small neighborhood—modest for Earth but unprecedented for space.
That gives the National Aeronautics and Space Administration a tight deadline to turn a wildly complex idea into something real. The agency expects to lean on U.S. industry to design a reactor, get it to the moon and operate it. But any companies that sign on will face steep engineering hurdles and financial risks.
All the while, NASA and its contractors will be racing against China and Russia. Those countries have been exploring the idea of jointly deploying nuclear energy on the moon by the middle of the 2030s, possibly using the power for a lunar base China is developing. NASA leaders worry a rival could potentially use its own station to establish a keep-out zone on the lunar surface, limiting U.S. efforts to build up its own presence and gaining a strategic advantage in space.
Here is what you need to know about U.S. plans to get a reactor to the moon.
Why do it?
The Apollo program successfully delivered astronauts to the moon a half-dozen times. What it didn’t do was create a lasting U.S. presence there.
A permanent nuclear reactor could open up new possibilities—including a science-fiction future where moon outposts spark new scientific and economic activities around research, mining, tourism and more. A nuclear reactor offers consistency that solar power with batteries can’t manage—given the two-week lunar night—and would generate about a decade of electricity.
Bhavya Lal, a former high-ranking technology official at NASA, says fission energy would allow government and private companies to start developing permanent settlements.
“It isn’t about doing the same missions better. It’s about doing fundamentally new missions,” Lal says.
Steven Sinacore, NASA’s program executive for fission surface power, says that nuclear energy is a crucial technology for establishing continuous U.S. operations on the lunar surface and beyond. “We want to go to the moon. We want to go to Mars,” he says. “This is the enabling technology.”
How would it work?
It is difficult to build and operate nuclear-power systems on Earth. Making one work on the moon won’t be any easier.
“I think there are a lot of folks that think we can just put lander legs on a terrestrial micro reactor and fly it to the moon and we’re good to go. And that couldn’t be further from the truth,” says Bill Pratt, director of in-space infrastructure at Lockheed Martin.
One challenge is cooling. On Earth, reactors are usually located near bodies of water for cooling the reactor core, and they can dissipate heat in the atmosphere. But there is no water or air in space. Instead, large radiator panels must be built to shed heat, adding to the overall mass of the project. Heavy radiation shielding, too, would be needed to protect the lunar environment and astronauts.
How would a reactor get to the moon?
A powerful rocket will be needed to get the reactor into space in the first place. Elon Musk’s SpaceX, Jeff Bezos’ Blue Origin or United Launch Alliance, owned by Boeing and Lockheed Martin, could potentially handle the flight. The project will also need a landing vehicle capable of taking the reactor to the lunar surface, which presents many complications: Since the moon pretty much doesn’t have an atmosphere, a landing vehicle will need a propulsion system to slow its descent, stores of fuel for that operation and a sophisticated guidance system to pull off a soft landing.
NASA’s directive assumes the existence of a lunar lander capable of delivering up to 15 metric tons to the surface. That is a huge amount. By contrast, Texas-based Firefly Aerospace landed about one-tenth of a metric ton on the moon earlier this year.
Can a reactor be launched safely?
Before a rocket goes up, regulators will want to know what would happen in the event of an explosion, says James Walker, chief executive at reactor developer Nano Nuclear Energy. “How far would fuel be dispersed? How would you pick it up?” he asks.
John Kennedy, director of emerging technologies at reactor developer X-energy, says that a lunar reactor wouldn’t be operating at takeoff, and control mechanisms would be locked to prevent the fission process from starting. “You literally can’t turn the reactor on until you’ve landed on the moon’s surface,” he says.
Meanwhile, some reactors under development would use coated pebbles of uranium—which could be helpful in case of an accident. The coating could help the pebbles stay intact and help with containment, says Walker.
Once on the moon, Walker says, “your risks kind of diminish.”
Are there regulations to cover lunar reactors?
On Earth, there are norms for safety zones around reactors. Those don’t exist on the moon, and establishing zones would have technical and geopolitical implications, says Lal, the former NASA official.
“Should the safety zone be half a kilometer? Ten kilometers? More?” she says. “Are we going to tell China not to put their reactor close to ours, and how will that happen?”
The 1967 Outer Space Treaty, signed by the U.S., China, Russia and other countries, provides a framework for how nations interact in space. It is light on many specifics, meaning countries will need to discuss details, according to Christopher Johnson, director of legal affairs and space law at the Secure World Foundation.
Meanwhile, in 2019 President Trump signed a memorandum that outlines how a reactor in space would be licensed—but the process hasn’t been tried yet for a fission launch, says Lal, who helped write the memo.
Then there’s the matter of liability. The domestic nuclear-power industry relies on the Price-Anderson Act, which limits liability as a way to enable investment. Something similar will be needed in space, or companies won’t be able to get private insurance to cover their efforts.
Can nuclear scale up in space?
Nuclear energy in space isn’t new, but efforts so far have been small scale, such as powering space probes. In 2018, as a step toward a lunar or Mars reactor, NASA and the Energy Department demonstrated a reactor that generated enough power for a small household for a little more than a day. A fully realized lunar reactor would need to generate 100 times as much. “There’s going to be some work done,” says Koroush Shirvan, an MIT professor who specializes in advanced nuclear reactor technology. “That power system is going to be a very massive part of the whole technology.”