Helium-3 reality check: the buyers are real, the reactors aren't

Lunar helium-3 has signed customers now. They want it for quantum fridges, not fusion. Here's what's contracted and what isn't.

By Mars Mining Desk · Last reviewed Oct 21, 2026

For forty years helium-3 was the punchline of Moon mining: an isotope for fusion reactors that didn’t exist, mined by machines that didn’t exist either. That changed quietly in 2025, when the buyers showed up and none of them were fusion companies.

In May 2025 Interlune announced that the U.S. Department of Energy Isotope Program had agreed to buy three liters of lunar helium-3, delivered no later than April 2029, at approximately the commercial market price of the day. In September 2025 the Finnish cryogenics company Bluefors agreed to buy up to 10,000 liters a year for delivery from 2028 to 2037. Maybell Quantum, another dilution-refrigerator maker, is on the list too, announced as Interlune’s first commercial customer.

The common thread is dilution refrigerators. Bluefors says its machines reach below 10 millikelvin, the temperatures superconducting qubits need, and that it has shipped more than 1,500 of them. Helium-3 is the working fluid, it is scarce on Earth, and Interlune’s release notes that government has been hunting for a new supply since a severe shortage around 2010.

So demand is real and it is not speculative in the fusion sense. Supply is the problem. Interlune itself says producing the DOE’s three liters means processing enough regolith to fill a large backyard swimming pool. Bluefors’ upper bound is more than three thousand times that per year.

The date that doesn’t fit

Now line up the calendar. Interlune’s Prospect Moon payload, funded by a $6.9 million NASA contract, is the mission that will first measure helium concentrations in place and test extraction. It will be ready for lander integration in September 2027, and Interlune is still looking for a ride for a 2028 launch. The Bluefors delivery window opens in 2028 and the DOE deadline is April 2029.

A measurement mission and a delivery deadline in roughly the same year is not a plan you can execute serially. Either Interlune expects early deliveries from Earth-sourced helium-3 (in July 2026 it announced it had produced pure helium-3 from domestic helium with a cryogenic process), or the lunar dates slip. The “up to” in the Bluefors deal is doing a lot of work, and so is “no later than.”

Europe is asking the blunt version of the question. ESA’s new Lunavest study, led by Poland’s MIRORES, explicitly treats helium-3 as the main candidate for export to Earth and asks whether the full chain closes, not just the extraction step.

Our view: helium-3 is the first lunar resource with a plausible Earth customer at Earth prices, which makes it more interesting than water for investors and less interesting for exploration. We expect the first “lunar” deliveries to be small, late, or partly terrestrial.

What would change our mind: Prospect Moon measuring concentrations at the high end of the Apollo-derived estimates, plus a funded harvester mission with a lander contract. Both, not one.

Not affiliated with NASA, SpaceX or any agency or company mentioned. Not investment advice. Disclaimer.