The United States wants a reactor on the
moon by 2030. A Russian-Chinese alliance is working on one for 2036. Some leading
scientists say the danger is great.
·
A new space race:
NASA is aiming to launch a lunar reactor by December 2030, while Russia says it
plans to deliver one by 2036 for a China-led lunar programme.
·
Why reactors matter:
Solar power cannot provide steady electricity through the moon’s nights, which
last more than two Earth weeks. Nuclear reactors could supply reliable power
for a permanent base, though early missions may use solar and radioisotope
systems.
·
Different plans:
NASA’s proposed Lunar Reactor 1 would generate 20 kilowatts for five years
without intervention. Russia’s planned Selena reactor is designed to generate
up to 10 kilowatts and operate autonomously for a decade.
·
Uncertain schedules and designs:
Neither country has a proven system for landing a heavy reactor on the moon,
and lunar bases have not yet been built. Experts expect timelines and technical
plans may change.
·
Launch and accident risks:
Even if reactors remain inactive until reaching the moon, a launch failure
could scatter fuel or cause other hazards. Experts also point to risks from a
malfunction or uncontrolled return to Earth.
·
Limited containment on the moon:
Lunar reactors would lack the substantial containment structures used on Earth.
Accidents could spread radioactive debris over wide areas, and both U.S. and
Russian plans reportedly involve leaving spent material on the moon.
·
Fuel concerns:
NASA says it plans to use high-assay low-enriched uranium (HALEU), but U.S.
supplies are limited and Russian imports are banned. Experts have also raised
concerns about proposals involving highly enriched uranium, which could pose
proliferation risks.
·
Technical challenges remain:
Space reactors still face unresolved questions about cooling, radiation
shielding, durability and safe operation in low gravity. None of the proposed
microreactors is yet proven for lunar use.
·
Geopolitics shapes the effort:
The U.S. is concerned that a Russian-Chinese reactor could give the partnership
strategic influence over lunar sites and resources. Some experts argue
international cooperation would improve safety and scientific progress.
In
late August, NASA asked contractors to prepare to build a nuclear reactor that could
survive a space voyage and run without maintenance near the moon’s south pole. That
may sound like science fiction, but the agency wants it ready to be launched by
December 2030.
There
is a reason for the rush. Russia aims to have a lunar reactor running by 2036 as
part of a secretive partnership with China. NASA has already sped up its schedule
to beat its rivals.
The
race is for the very future of space exploration. The United States and China want
to be first to establish a moon base, to search for resources like frozen water
and to launch missions deeper into the solar system. Controlling access to the moon’s
assets is vital to this mission. Both superpowers believe a nuclear reactor is the
centerpiece of this ambition.
The
countries plan to turn on their reactors only after they reach the moon. But some
leading scientists caution that governments are moving too quickly in an era of
space exploration that has seen some notable disasters. In the last six years, multiple
Chinese, American and Russian rockets have failed and exploded, and a Russian lander
has crashed into the moon. Space junk regularly tumbles to Earth.
Failures
could cause a chain reaction with dire consequences. Falling reactor debris could
scatter radioactive material, as happened in Canada in the late 1970s. An explosion
or a meltdown on the moon’s surface would risk turning entire regions into no-go
zones.
“There
will always be a space race going on, and if you enter nuclear power into that mix,
then it could take a potentially more dangerous turn,” said Edwin Lyman, the director
of nuclear power safety at the Union of Concerned Scientists.
A
review of technical specifications, procurement documents and academic research,
along with interviews with industry insiders, government officials and critics,
offers the clearest picture to date of how China, Russia and the United States are
pursuing this nuclear ambition.
The
records also help explain a key aspect of the Chinese-Russian space partnership,
an alliance championed by Presidents Xi Jinping and Vladimir
V. Putin.
Nuclear
power appears to be the only core task that China has delegated to its partner in
the lunar project. No country has more experience than Russia in this area. It launched
more than 30 reactors into orbit, mostly in the 1970s and 1980s, aboard Cold War-era
satellites, and it is a leader in civilian nuclear power. Russia controls the largest
supply of what is considered the safest nuclear fuel for space missions. That fuel,
uranium that is not highly enriched, is in short supply in the United States.
“Russia
has practically no competitors in the field of space nuclear energy,” Mikhail Kovalchuk,
the president of Kurchatov Institute, told the Russian news agency TASS. Kurchatov,
a research agency, is helping design a lunar reactor.
NASA
is playing catch-up. The agency launched a reactor in 1965 but shut it down after
an unrelated spacecraft failure. The United States has spent more than $20 billion
on space nuclear programs since then but has never deployed another reactor.
The
race for a lunar reactor is as much a spectacle of power as it is a matter of exploration.
President Trump has declared superiority in space to be part of his “America First”
agenda. Mr. Xi and Mr. Putin have made similar declarations.
Countries Say Lunar Nuclear
Power Is a Must
Any
permanent base on the moon requires reliable power. Nuclear reactors do not need
sunlight to work, and they can be compact. With the right design, they require little
human intervention, according to NASA and the Kurchatov Institute.
For
the first few years, the United States and China would need only enough power to
keep equipment warm and to charge rovers, vehicles that roam the surface. For that,
they plan to use solar power and radioisotope power systems.
These
systems convert heat from the natural radioactive decay of isotopes into electricity.
The United States, Russia and China have used the systems in space already.
But
an expanded lunar base would need a lot more power than those systems can generate.
Solar panels would not work during cold lunar nights that stretch over two weeks
of Earth time. Any power system near the moon’s south pole would have to survive
temperature swings between 130 and -334 degrees Fahrenheit.
Moscow
has tasked its state-owned agencies with delivering a lunar reactor, called Selena,
by 2036 to power the lunar stations led by China. Selena would generate up to 10
kilowatts of electricity and be able to operate autonomously for a decade. It would
share features with an earlier reactor that was designed to operate in the Arctic.
NASA
has accelerated its timeline, fearing that a Russian-Chinese reactor could establish
a de facto exclusion zone on the moon. NASA’s Lunar Reactor 1 is expected to produce
20 kilowatts of electricity (roughly the power use of 16 American homes) and work
for five years with no intervention.
As
a first step, NASA plans to use nuclear power to propel a spacecraft to Mars in
December 2028. This has never been done.
In
parallel, the Pentagon intends to develop its own space reactors for deployment
in orbit and on the moon, according to the White House.
Target
dates have repeatedly slipped, and few experts expect the countries to meet their
deadlines. Nobody has a proven lander that can lower heavy, potentially radioactive
material onto bumpy lunar terrain. Nobody has ever installed a reactor in low gravity.
The
moon bases have not been built, and how much electricity they would need is open
to speculation. That is why experts say that all or parts of the reactor designs
could change.
“Nothing
is for certain right now,” said Julien de Troullioud de
Lanversin, a nuclear scientist and professor at the Hong
Kong University of Science and Technology.
There Is Plenty of Risk
The
United States and Russia say their reactors would be inoperative — what scientists
call unirradiated — until they arrived on the moon. This would reduce risk. Nuclear
engineers say that “cold” uranium fuel poses little radioactive threat even if it
tumbles to Earth.
Still,
things can go wrong, especially during the controlled explosion of a rocket launch.
“This
is the moment when there is a lot of risk,” said Leopold Summerer, who leads a United
Nations working group on nuclear power in outer space. “We had many launch failures,
so we have a lot of data on what can go wrong.”
Take,
for example, a reactor splashing into an ocean. Water slows down neutrons, making
them more likely to split atoms. This could cause havoc by making a reactor go critical,
meaning it would enter a chain reaction of splitting atoms that releases radiation.
The risk is real because most launchpads are near a body of water.
Nuclear
experts say this probably happened in Russia in 2019, when a reactor-powered cruise
missile failed and plunged into the White Sea. When researchers tried to recover
it, a nuclear reaction occurred, according to the U.S. Department of State. At least
five workers died. (Russia denied these claims and said the missile was not powered
by a reactor.)
NASA’s
specifications call for a design that can prevent this outcome. Rosatom, Russia’s
state-owned nuclear energy company, declined to comment, saying its space program
was classified. The Kurchatov Institute, which is in charge of the science, and
Roscosmos, in charge of the Russian space program, did not respond to questions.
The Chinese Ministry of Foreign Affairs and the China Manned Space Agency did not
respond to questions, either.
The
other risk is a malfunction that could bring the reactor back to Earth after operation.
In 1978, the uncontrolled re-entry of a Russian nuclear-powered satellite, Kosmos
954, scattered radioactive matter across nearly 48,000 square miles of Canada’s
north. After about a year of cleanup, only 0.1 percent of the satellite’s power
source was recovered.
In
the United States, any space reactor is supposed to be reviewed by experts from
seven agencies. But it is impossible to rule out accidents.
“The
definition of an accident is things don’t go according to plan,” R. Scott Kemp,
an associate professor of nuclear science and engineering at the Massachusetts Institute
of Technology, said.
Dr.
Kemp said accidents were more probable on the moon.
On
Earth, reactors are cocooned inside containment structures, which would be extremely
expensive and technically challenging to build on the moon. NASA has said its reactor
would be shielded, though it is unclear how. The lunar reactors would likely be
ringed by no-go zones to reduce radiation risk for astronauts and machines, experts
said.
With
little containment, even smaller accidents would produce much more radioactive fallout,
Dr. Kemp said. There is no wind on the moon but, with less gravity, debris can travel
far after an explosion.
On
Earth, when a reactor reaches the end of its life, decommissioning is a complicated,
careful process that takes years. On the moon, both NASA and the Russian agencies
say they would simply leave the radioactive material behind.
“On
a race, they don’t want to be bothered with a difficult problem that nobody has
a solution for,” Dr. de Troullioud, the nuclear scientist
in Hong Kong, said.
A Fuel Challenge
In
all its technical and procurement documents, NASA says it would use a nuclear fuel
that is not highly enriched and is regarded as safest for advanced reactors.
But
some experts say geopolitics and a tight deadline could complicate matters.
The
last space reactor NASA tested, in 2018, used highly enriched uranium, which is
lighter and cheaper to launch than other fuels. But the first Trump administration
discouraged using this fuel because it could end up as a nuclear weapon.
Now,
NASA wants to use a fuel known as high-assay low-enriched uranium, or HALEU, which
is in short supply in the United States. Russia is the biggest producer, but the
United States has banned Russian uranium imports since 2024 because of the war in
Ukraine.
NASA
documents show that it expects the Department of Energy to allocate low-enriched
fuel for space reactors. But the government itself has struggled to produce enough
fuel.
The
Russian-Chinese alliance has not disclosed what type of fuel would be used. Russia’s
older space reactors used highly enriched fuel.
“It
doesn’t take anything more than a machine shop and a little bit of high explosive
to turn this into a very credible weapon,” said Representative Bill Foster, Democrat
of Illinois, a physicist who successfully discouraged the use of highly enriched
uranium in space reactors.
At
least one potential bidder for NASA’s lunar reactor contract, Space Nuclear Power
Corporation, is developing a reactor using highly enriched uranium. A company founder
declined to comment, “given the competitive nature” of the upcoming projects.
The
U.S. space program could be a boon for companies that make microreactors, which
can generate up to 10 megawatts of electricity. These expensive reactors are too
small to meet the energy demands of data centers, but
they have found a niche business in space and military applications.
Last
month the Pentagon selected a company, Antares, to develop and demonstrate a microreactor
for space. Antares was among five companies that successfully tested reactors this
summer under a program run by the Department of Energy. The company said it would
bid for NASA and Pentagon contracts for lunar reactors.
Microreactors
may eventually end up on the moon, but none are proven and ready. Fundamental safety
questions — how to get rid of heat, how to shield the reactor, how to maintain the
structural integrity — have not been fully resolved for space reactors, which must
be compact and light.
“It
is entirely feasible to put a reactor on the moon,” said Katy Huff, who leads the
department of nuclear engineering and engineering physics at the University of Wisconsin-Madison.
But the more power needed, she said, the more challenging reactors are to build.
For
all the elbowing to get there first, Dr. Huff said governments had accomplished
more by working together than by competing.
“I
want to see more collaboration internationally in space,” she said. “That is where
collaborative team science has ascended beyond our grumpy international politics.”