Interlune produces helium-3 using a process designed for the moon – GeekWire
Seattle-based Interlune says it has been able to produce 99% pure helium-3 from standard industrial-grade helium, marking a technological milestone the company aims to use on the moon.
The process, known as Cold Capture, can be used to advantage on Earth even before Interlune begins lunar mining operations.
Only 0.000137% of the Earth’s helium exists in the form of helium-3, as opposed to the more common helium-4 isotope. But helium-3 is particularly suitable for use as a refrigerant for quantum computers. It can also be used in radiation detectors, medical scanners and eventually fusion reactors.
Due to its rarity and ease of use, the price of helium-3 can reach $20 million per kilogram ($9 million per pound). Interlune bets on the proposition that helium-3 is more abundant and easier to access on the moon, due to the exposure of the lunar surface to the solar wind. If Interlune’s business model works, the company will be able to make a profit by bringing lunar helium-3 to Earth for industrial use.
Interlune’s original goal was to demonstrate that Cold Capture could work as advertised. The process uses cryogenic distillation to separate helium-3 from normal helium at temperatures approaching absolute zero.
“Capturing helium-3 from existing helium sounds deceptively simple,” said Gary Lai, Interlune’s chief technology officer, in a news release. But helium-3 and ordinary helium are chemically almost identical, making them unusually difficult to separate.
Interlune demonstrated Cold Capture on a small scale in early 2025, and received a $1.25 million small business grant from the Air Force Department last November to scale up the technology to commercial production.
Based on tests done since then, Interlune projects that its technology could triple the domestic production rate of helium-3.
“Every liter of helium produced in the world contains a small amount of helium-3,” said Rob Meyerson, founder and CEO of Interlune. “Cold Capture connects to the existing helium liquefaction infrastructure to recover that helium-3 and turn it into a valuable product.”
Interlune has already entered into agreements with the US Department of Energy and Maybell Quantum to deliver helium-3 shipments. The first shipment may have come from terrestrial sources of helium, courtesy of Cold Capture.
Meanwhile, the company follows a step-by-step plan for monthly testing and production. A camera designed to measure the moon’s helium-3 levels will be sent to the moon later this year on Astrobotic’s Griffin-1 lander.
That mission, known as Crescent Moon, is expected to pave the way for a NASA-backed probe called Prospect Moon in 2028. The experiment will test ways to extract gases such as helium-3 and hydrogen from lunar soil and rocks.
Follow-up missions may focus on harvesting hydrogen for rocket fuel and other lunar power applications, while collecting helium-3 for delivery to Earth.
Interlune was founded in 2020 and reported raising $18 million in seed funding by 2024. This January, the company announced an additional $5 million investment offering aimed at advancing key technological advances.
