US Transport Secretary Sean Duffy has announced the US wants to be the first nation to put a nuclear reactor on the Moon after an internal directive showed he ordered the space agency NASA to fast-track the plan.
"We're going to bring nuclear fission to the lunar surface to power our base," Mr Duffy wrote on social media X on Thursday, local time.
"If you lead in space, you lead on Earth."
A directive written by Mr Duffy — first reported by Politico and seen by Agence France Presse (AFP) — demands that NASA build a nuclear reactor that could be used to generate power on the Moon within five years.
It is the first major policy change by Mr Duffy since President Donald Trump appointed him as acting head of the space agency, and it comes just three months after China and Russia announced they were considering a joint effort to also put a nuclear power station on the Moon.
But what would a nuclear reactor help achieve? And what is driving this new space race? Here's what to know.
What is a nuclear reactor?
Nuclear reactors are the heart of a nuclear power plant. They create electricity by producing a carefully controlled nuclear chain reaction.
According to the New York Times, Mr Duffy's directive calls for the agency to solicit proposals from commercial companies for a reactor that could generate 100 kilowatts of power and would be ready for launch in late 2029.
That's enough electricity to power between 50 and 100 Australian households at once.
As extraordinary as it sounds, this idea to use nuclear energy in space is not new.
Since 2000, NASA has been investing in nuclear reactor research, including in 2022, when it awarded three US$5 million contracts to develop initial designs for the Moon.
But those designs were smaller, producing 40 kilowatts, and were for demonstration purposes to show nuclear power "is a safe, clean, reliable option," NASA said at the time.
Why put one on the Moon?
A nuclear reactor would be useful for long-term stays on the Moon, as the Trump administration looks to revitalise space exploration.
One lunar day lasts four weeks on Earth, with two weeks of continual sunshine followed by two weeks of cold darkness.
This cycle makes it difficult for a spacecraft or a Moon base to survive with just solar panels and batteries.
Having a source of power independent of the Sun would be key to a sustained human presence on the lunar surface for at least 10 years, NASA has previously said.
In the internal directive, Mr Duffy also cites China and Russia's plans to put a reactor on the moon by the mid-2030s.
"The first country to do so could potentially declare a keep-out zone which would significantly inhibit the United States from establishing a planned Artemis presence if not there first," he writes, according to AFP.
Artemis is a reference to NASA's Moon exploration program, which aims to send four astronauts to the lunar surface in 2026 to establish a lasting presence near the south pole.
Further, Mr Duffy notes it would pave the way for Mars exploration efforts.
"To properly advance this critical technology to be able to support a future lunar economy, high-power energy generation on Mars, and to strengthen our national security in space, it is imperative the agency move quickly," he reportedly says.
Amid renewed competition for space dominance — more than 50 years after the Cold War spurred the first man to walk on the Moon — it is worth noting that a 1967 UN agreement says no nation can own the Moon.
Mr Duffy's comments about the potential for another country to declare a "keep-out zone" on its surface appear to be referring to an agreement called the Artemis Accords.
In 2020, seven nations initially signed the agreement to establish principles on how countries should cooperate on the Moon. Since then, 49 more have done so, including Australia, but China is noticeably absent from the list.
These principles include so-called "safety zones" to be established around operations and assets that countries build on the Moon to prevent interference.
So, what is behind this lunar race?
The race to the Moon is driven by scientific knowledge and technological advances, as well as the prospect of accessing valuable resources.
In a 2015 article published on its website, NASA explains why it plans to mine the Moon and how the "lunar gold rush" could work.
Citing data from geological surveys, the space agency says the Moon contains three crucial elements: water, helium and rare earth metals.
The water reserves frozen inside shadowed craters could be used for drinking, and could even be converted into rocket fuel to support future missions to Mars, according to NASA.
The agency says helium would support developments in the energy sector, like nuclear fusion.
As for rare earth metals, it says they would boost the supplies needed for emerging technologies, like smartphones, computers and medical equipment.
China has also tapped the Moon's potential and made giant leaps in space exploration and technology in recent years.
It has built a space station that is manned by taikonauts, landed a rover on Mars, and became the first nation to touch down on the far side of the Moon.
China, too, wants to set up a lunar base and send people to Mars, adding a layer of political rivalry to the race.
