The Seattle-based startup Interlune has developed a lab technique to simulate lunar regolith exposed to billions of years of solar wind, tackling a key obstacle in its plan to mine helium-3 from the Moon. Helium-3, a rare isotope embedded in lunar soil by the solar wind, has long-term promise for fusion energy and nearer-term uses in cryogenics, medical research and neutron detection, making it one of the few lunar resources that could plausibly be profitably returned to Earth. Since genuine lunar samples are scarce and existing simulants replicate the Moon's geology but not its precise chemistry, Interlune needed another way to test its extraction hardware before committing to a costly mission.

In a vacuum chamber, the company's scientists fired accelerated ionised helium into regolith, compressing roughly 15,000 years' worth of solar wind exposure into about four hours. Heating the material afterwards, they found the implanted helium was released at the same temperatures observed in real Apollo-era rock samples, confirming the simulant's accuracy. Interlune, led by chief executive Rob Meyerson and scientist Elizabeth Frank, intends to use the material to test its own extraction and processing equipment and to sell it to other lunar mining firms, ahead of a planned prototype mission on a lunar lander later this decade.