Seattle firm sets out to prove Moon helium-3 mining is actually feasible
US company Interlune is investigating whether the rare isotope helium-3, deposited in lunar soil by billions of years of solar wind, could realistically be extracted. Before any full-scale mining hardware is sent to the Moon, the underlying process needs to be shown to work.
As part of the Sun's nuclear fusion processes, it produces a rare isotope called helium-3. Some of it escapes into the solar wind, a stream of charged particles that spreads across the Solar System and has bombarded nearby bodies, including the Moon, for billions of years.
Because the Moon has neither a magnetic field nor an atmosphere to shield it, helium-3 ions have steadily embedded themselves in its surface soil, known as regolith. The ions only penetrate a short distance into individual soil grains, but repeated meteorite impacts over time have churned the surface, mixing some helium-3 slightly deeper into the ground.
Concentrations remain modest — around 10 to 20 parts per billion in some titanium-rich soils, which hold onto the ions more effectively. Still, this is far higher than on Earth, which is largely protected from the solar wind by its own magnetic field.
Is mining actually practical?
The idea of harvesting lunar helium-3 has long attracted scientists and engineers, notably geologist and former Apollo 17 astronaut Harrison "Jack" Schmitt. Many believe it could eventually power fusion reactors. In the nearer term, it has more immediate applications, including cooling materials to extremely low temperatures, supporting medical research, and enabling neutron detection.
This makes helium-3 one of the few lunar materials that could plausibly be mined and transported back to Earth at a profit. As a result, several companies, including Seattle-based Interlune, have expressed interest in pursuing lunar helium-3 extraction.
Before any company can deploy a full-scale extraction system to sift through lunar regolith and collect helium-3, however, it first needs to be established whether doing so is physically practical.
