Plan to harvest helium-3 from lunar surface reaches prototyping milestone

A US startup is looking to our closest satellite to fill a resources gap here on Earth. Helium-3 is rare on terra firma, but is thought to be abundant in the regolith of the Moon. Interlune has now revealed a full-scale excavator prototype that forms a key component of its lunar Harvester.

The shortage of helium-3 – a stable isotope of helium important for applications ranging from energy production to medical research – was first identified in the US toward the middle of 2008. The US government officially recognized the issue in early 2009, and mitigation efforts put in place.

"The United States supply of 3He comes from the decay of tritium (3H), which the Nation had in large quantities because of our nuclear weapons complex; however, the tritium stockpile has declined in recent years through radioactive decay and is expected to decline in the future because of reduced demand for tritium," read the intro to a National Isotope Development Center newsletter from 2014.

While quantities of helium-3 on Earth are in short supply, it's thought that the Moon has "been bombarded with large quantities of helium-3 by the solar wind." Interlune is looking to mine this untapped resource and transport it to Earth, and has received backing from the US Department of Energy and NASA, as well as the National Science Foundation, to develop extraction and separation technologies.

The Interlune harvesting process involves four main stages – excavation, sorting, extracting and separating. For the first phase, the company has partnered with heavy industry machinery maker Vermeer, and a sub-scale prototype was developed and tested by the middle of last year. Now the collaboration has revealed a full-scale prototype designed to reduce "tractive force, power consumption, and dust compared to traditional trench-digging techniques."

Actual details on the prototype are somewhat lacking, but the electric excavator is expected to be capable of digging into the regolith and remove up to 100 metric tons every hour, and will operate continuously. The final design will be incorporated into the Interlune Harvester, and will route the regolith to the sorting component before extraction and separation of the resource. The stripped regolith will then be returned to the lunar surface.

Interlune says that it is actively developing and testing these other components in simulated lunar gravity and at its cryogenic lab based at the company's Seattle headquarters. The development timeline calls for a pilot harvesting plant to be on the Moon by 2029, following a lunar mission to validate concentrations of helium-3 in 2027. Full operation and sales to customers are expected to start from the early 2030s.

Interlune is not alone in its plans to get heavy machinery working to cash in on the Moon's untapped bounty. Japan's Komatsu revealed its electric excavator prototype at CES 2025, which looks to be aimed more at lunar construction projects than tapping the regolith for rare isotopes.

Source: Interlune