NASA’s lunar – NASA’s plan to land a nuclear fission reactor on the lunar surface by 2030 has lit a fuse in a new era of space competition—one where power could be essential for surviving the long lunar night, but where rushing the design, launch, and landing could leave saf
When a U.S. senior official said NASA would put a nuclear reactor on the Moon by 2030, the idea landed with a jolt. Last year—less than a month after being named acting administrator of NASA—U.S. Secretary of Transportation Sean Duffy said the reactor would be designed. built. flown. and delivered to the lunar surface by 2030. as part of strengthening U.S. national security in space.
For many observers, the timing sounded wild. A nuclear reactor is one thing on Earth; it’s another to imagine it in a volcanic. airless desert with extreme temperature swings. frequent asteroid strikes. and protracted quakes. Even so. the argument for doing it is hard to shake: if America wants a permanent. inhabited presence on the Moon—able to operate through the frigid and lengthy lunar night—solar power won’t cut it. Through Artemis. NASA has been trying to transform the Moon into a scientific outpost. a mining site. and a Mars-bound launchpad.
Simon Middleburgh. co-director of the Nuclear Futures Institute at Bangor University in Wales. put it bluntly: “It’s the only way we can sustain a lunar base properly long-term.” He also said it isn’t just the U.S. eyeing the idea. China and Russia are teaming up to put their own reactor on the Moon by 2035. to electrify what they call the International Lunar Research Station. planned for the lunar south pole. Sooner or later, Middleburgh said, “nuclear power on the moon will happen,” calling it “inevitable.”.
The dispute now isn’t whether nuclear power could work. It’s whether the U.S. could deliver it with enough caution, fast enough to satisfy a race.
Bhavya Lal—now a professor of space policy at the RAND School of Public Policy and previously NASA’s former acting chief technologist and associate administrator for technology. policy and strategy—questioned both timing and scale. A reactor capable of powering 80 American households on the lunar south pole by 2030. in an environment no human has yet set foot in. she said sounded rushed. if not impossible. “I think the worst-case scenario might be [that] in the quest to be first we skip important design and safety steps. ” Lal said. “It’s good to be first—competition is good—but we need to do it right.”.
That tension is now colliding with the timeline NASA says it intends to meet. In January, NASA’s current administrator, Jared Isaacman, reaffirmed the plan to put nuclear fission power on the Moon. In March. Isaacman announced that NASA would launch the first interplanetary spacecraft powered by nuclear electric propulsion—the Space Reactor-1 Freedom—to Mars by the end of 2028. The mission, NASA said, would help test nuclear fission technology in deep space before the U.S. establishes a nuclear power plant on the lunar surface.
Lal said she was confident that “no reactor the U.S. launches will have safety concerns,” but added that “obviously things can always go wrong, and there’s no such thing as 100 percent safe anywhere in the world—and anybody who says [they’ve achieved] that is lying.”
Behind the optimism. the path is still narrow: to put a nuclear reactor on the Moon. it must first ride a rocket. Lindsey Holmes. an expert in space nuclear technology and vice president of advanced projects at Analytical Mechanics Associates. said keeping a reactor safe for launch is one of the biggest factors.
The U.S. has tried nuclear power off-planet before. In 1965. the experimental Systems for Nuclear Auxiliary Power 10A reactor became the first nuclear reactor sent to space. powering 600 watts in a wastebasket-sized box for just 43 days before a voltage regulator broke. It is still orbiting the planet today, and remains America’s sole attempt at operating a nuclear reactor off-planet.
The Soviet Union, by contrast, propelled more than two dozen nuclear reactors beyond Earth’s atmosphere, often used to power radar spy satellites, with most going up without incident. Holmes said one reactor did something far worse: it “spewed radioactive stuff all over Canada.”
The story traces back to the Kosmos 954 mission. Launched in September 1977, the spacecraft began moving off target about three months after launch. Both Soviet operators and U.S. officials noticed it wobbling, and the Soviets initially kept quiet. Their engineers tried to eject the satellite’s active nuclear reactor into space before the vehicle crashed back to Earth. but the effort failed. Eventually. the Soviet Union acknowledged the issue to American counterparts. but claimed Kosmos 954 would incinerate without consequence during its unstoppable atmospheric reentry.
Instead, in January 1978, Kosmos 954 showered deadly debris over a 15,000-square-mile patch of Canada’s relatively sparsely inhabited Northern Territories. During a joint Canadian-American operation called Morning Light, hazmat-suited agents scoured the frozen region for the shattered remains. Some parts weren’t highly radioactive. but other fragments made team members’ personal radiation dosimeters register as “a field of crickets. ” according to one team member. Miraculously, it didn’t kill a single person. The Soviet Union paid Canada $3 million CAD in apology.
If that incident carries a lesson for today’s lunar plans. it is the one Huff—then an assistant secretary for nuclear energy in the Biden administration. and now a nuclear engineer at the University of Illinois at Urbana-Champaign—spelled out: don’t start a lunar reactor until it lands on the Moon. “Until you turn it on, there’s no nuclear waste inside,” she said.
Huff also challenged another fear that can distort the debate. Uranium, she said, is “radiologically very boring” when it is unused nuclear fuel. “It’s not particularly radioactive. ” she said during a recent video call. gesturing to an object on her desk and saying. “I have some uranium in that cardboard box right there.” Middleburgh echoed the practical point: “You can pick it up. It’s toxic more than anything else; it’s like lead. So don’t eat it.”.
The physics, Huff explained, change once uranium is inside a reactor and neutrons are fired at it. The unstable atomic nuclei split apart, releasing more neutrons and driving a fission reaction that produces heat. That heat can then be used to turn a fluid—often water in many terrestrial designs—into steam. which rotates a turbine and generates electricity. But after fission. keeping uranium isn’t the danger; the problem is that the products that remain after the reaction begins can be highly radioactive. which is why waste is dangerous.
Still, in space, the advantage is endurance. A nuclear cascade can continue for a long time, providing power for years, maybe decades, without refueling.
The idea of nuclear power beyond Earth isn’t new at all. Starting in the 1960s, the U.S. and the Soviet Union sent radioisotope thermoelectric generators—RTGs—into space to power satellites and science missions. including Apollo-era experiments on the Moon and Mars rovers and deep-space probes. But RTGs aren’t nuclear reactors; they are closer to long-lasting nuclear batteries, providing a small but steady heat source. That kind of power won’t supply a Moon base, experts said.
Astronauts need electricity and heat to operate during the lunar night. and they also need enough power for extraction and production—drawing water from lunar soil and splitting it into hydrogen and oxygen for rocket fuel. For that. NASA and industry partners have been working on designs for a 40-kilowatt lunar reactor for the past several years. across both the first Trump administration and the Biden administration.
Then Duffy’s brief tenure changed the target. The plan jumped to 100 kilowatts. Huff said she found no evidence that the number was grounded beyond “it being bigger.” Compared to a standard U.S. nuclear reactor on Earth. 100 kilowatts is tiny—about 10. 000 times less powerful and only the size of a large car—yet Huff called it “huge for space. ” noting it is a full order of magnitude greater than the output of any other nuclear reactor launched off-world.
Sebastian Corbisiero, national technical director for the U.S. Department of Energy’s space reactor program, said a bespoke 100-kilowatt reactor on the Moon in four years is “an aggressive but achievable goal.”
What makes it hard isn’t just the engineering. It’s the environment it has to survive.
The Moon’s temperature swings are extreme, regularly moving from 250 degrees Fahrenheit during the day to –208 degrees F at night. There are moonquakes, and frequent small asteroid impacts leave craters at random times and locations.
Yet nuclear reactors themselves are not, experts say, naturally prone to dramatic explosions. Middleburgh compared them to the worst public examples: people think of Fukushima and Chernobyl. but “we don’t think of the ones that have been floating in our oceans.” He pointed to the robustness of nuclear technology around the world and to nuclear submarines. which operate in extreme environments. take knocks. and are designed to withstand combat scenarios.
A meltdown on the Moon, Huff said, would be a “truly ignoble achievement,” but not a Hollywood-style blast. If a reactor overheated to the point where fuel liquefied. modern reactor designs would aim to contain it within the plant. Still. that scenario would leave “a large. radioactive hunk of metal sitting there on the lunar surface. ” and it might keep people away for generations.
The most unforgiving consequence would be the risk to water ice. If melted reactor material contaminated an ice reserve—the kind of resource that would make a base possible—“Yikes,” Huff said. “It would be terrible. It would be very hard to forgive a nation willing to do that to the moon.”
Even without radiation being the immediate issue for astronaut health, a power failure would be catastrophic. Schmerr. a planetary seismologist and geophysicist at the University of Maryland. College Park. said that during lunar darkness. battery systems might have only “a modicum of juice” before they run dry. “Then the astronauts are in deep trouble because their entire life-support system goes down,” he said. “They’re not going to be able to survive.”.
NASA, for its part, says the system would be designed “with safety in mind,” according to a spokesperson speaking in the article.
But the real worst case. Corbisiero said. could be more mundane and more dangerous: the Moon might break the reactor and shut it down precisely when astronauts need it. That raises a practical question that sits behind every other technical discussion—how long can sensors and electronics last “in a fairly hostile environment?”.
Because the Moon is airless, the reactor would likely behave differently than Earth systems. Water could be a problem in space: in low gravity it doesn’t flow properly. and lunar temperature swings could cause steam to expand violently or water to freeze and break pipes. Huff and Middleburgh suggested the reactor would probably use air brought from Earth to take on heat and move it to a turbine.
Heat itself also has to go somewhere. Waste heat must escape, but without an atmosphere, there’s no easy sink. Huff said stopping overheating “is going to be hard in a vacuum,” and both Huff and Middleburgh pointed to a solution: sails—giant finlike structures designed to eject heat into space.
Then come the bullets: micrometeorites. “The moon is constantly being bombarded by extraterrestrial material,” Schmerr said. If multiple pebble-sized impacts puncture the radiator fins, the plant could fail to cool.
And if the damage is bigger than micrometeorites, astronauts have no shield. Schmerr said that during Apollo. new craters formed that were 70. 80 meters wide—about 230 to 260 feet—and if a team happened to be at ground zero for an impact. “you’re having a really bad day.” The base can’t defend itself against rarer. larger strikes.
One mitigation is to bury infrastructure. Schmerr said astronauts could bury the power plant underground, possibly using hollowed-out lava tubes, rather than leaving it exposed.
Moonquakes add another layer. The largest spotted by Apollo-era seismometers were between magnitudes 3 and 4—smaller than many Earth earthquakes—but they can last for several hours. “Not only is your system shaking, it’s shaking a lot for a long time,” Schmerr said. “This is not something we normally think about with structural construction here on Earth.”.
If the reactor sits too close to an active fault. even modest tremors could knock over taller structures and break parts. And if it isn’t fortified. three outcomes become possible: the reactor could break and stop working; fuel could be jiggled into an arrangement that slows the fission reaction; or the fuel could shift in a way that speeds it up. overheating until it requires a shutdown.
All of this engineering has to be validated without perfectly recreating lunar conditions. Corbisiero said that even with vacuum chambers simulating extreme temperatures and lack of atmosphere, the U.S. “does not have a facility where you can operate a reactor inside a vacuum chamber.” Reproducing lunar gravity in a laboratory. he said. would require an act of witchcraft.
The promise is still strong. Middleburgh said he was “enthusiastic” about a lunar reactor, and that the only way to know both whether it works and whether it works safely is to land it and switch it on.
Lal agreed on the ambition, but said she spends much of her time thinking about “all the things NASA could do wrong,” especially in a climate where the U.S. and other spacefaring nations may see power as leverage.
One flashpoint is interactions with China. Lal described a best-case future where China and the U.S. maintain separate patches of the lunar south pole, coordinate some operations, share scientific discoveries, and keep a respectful distance. “That’s the best-case scenario,” she said.
But she called that unlikely. “China and the U.S. are geopolitical rivals and competitors in the new race to claim the moon,” she said. “There’s new land, and it belongs to no one. Whoever gets there first makes the rules.”
International law doesn’t make the land-rush straightforward. The United Nations Outer Space Treaty. signed in 1967. says “outer space is not subject to national appropriation by claim of sovereignty. by means of use or occupation. or by any other means.” Nobody can legally own territory on the Moon.
Yet Duffy, in an August 2025 declaration, said nuclear power plants could be used to define a “keep-out zone” for other parties—marking sensitive equipment by warning others to stay away. Establishing a base, Lal said, can still grant a nation de facto control over a patch of the Moon.
And nuclear power plants can be placed like signals, she warned. Because they can be put anywhere for any purpose far from astronauts, both China and the U.S. could deploy them “like radioactive flags,” staking not quite legal claims on land they view as valuable—including swaths rich in water.
Lal said the U.S. shouldn’t let the competition set the rules by default. “We don’t want to not be the first to have a nuclear reactor on the moon,” she said. “The U.S. should be the first to land. to set the norms.” In her view. norms would include nonaggressive placement of safely designed nuclear reactors. and clear communication of reactor deployments so neighbors on the lunar surface can “talk to our friends and adversaries.”.
That’s the ideal. But she also pointed to how quickly suspicion can harden into unforced errors. If competition turns confrontational, she said, nuclear power plants may not be the only territorial markers nations try to place. “If they want to put a nuclear weapon on the moon, they will just do it,” Lal said. Putting nukes in space is illegal under the Outer Space Treaty. and yet Russia is thought to be developing one for this purpose. “If somebody wants to be nefarious. there is no way [to force] them not to be. ” Lal said. adding that the treaty is not legally enforceable—more a guideline than a brake.
For now. the immediate future still belongs to the engineers and the planners working toward a moon base powered by a reactor that has never before been designed for the lunar conditions. Middleburgh called for “overconservatism at the very beginning of the lunar nuclear endeavor. ” insisting that the first step must be careful.
And as the countdown toward 2030 takes shape—set by Duffy’s declaration. reaffirmed by Isaacman. supported by plans like Space Reactor-1 Freedom to Mars by the end of 2028—the question that hangs over every test and design choice is the one Lal said no one should lose sight of: “What happens if it goes wrong?”.
NASA nuclear reactor Moon Artemis Sean Duffy Jared Isaacman Space Reactor-1 Freedom space nuclear technology lunar south pole fission power Outer Space Treaty TRISO fuel moonquakes micrometeorites safety