Extracting helium-3 from lunar regolith.
Billions of years of solar wind have implanted helium-3 into the Moon's soil, the largest accessible reserve of a near-ideal fusion fuel. Turning that dust into usable gas comes down to one well-understood physical process and a hard economic question. Here is how lunar regolith processing works.
From regolith to refined helium-3 in four stages.
Excavation & Beneficiation
Regolith is collected from the top few meters of lunar soil and screened. Helium-3 concentrates in fine grains, so sorting for particle size below ~50 microns sharply raises yield per ton processed.
Thermal Volatilization
The sorted regolith is heated to roughly 700°C. Solar-wind-implanted volatiles, hydrogen, helium-3, helium-4, carbon, and nitrogen, desorb from the grains as a gas mixture without melting the soil.
Gas Separation
The released gases are cooled and fractionally distilled. Helium-3 is separated from helium-4 and other volatiles using cryogenic separation, exploiting the small mass and boiling-point differences.
Capture & Return
Purified helium-3 is compressed and stored for use in orbit or return to Earth. The co-extracted hydrogen, water, and carbon are valuable feedstock for in-situ life support and propellant.
Why lunar mining only makes sense at scale.
Helium-3 is extraordinarily dilute, on the order of a few parts per billion by mass in even the richer mare soils. Recovering a single ton of helium-3 means heating tens of millions of tons of regolith, which only pencils out with highly automated, continuously operating mining systems powered by abundant solar energy.
The economics improve when helium-3 is treated as one product of a broader in-situ resource utilization program. The same thermal step that releases helium-3 also yields water, hydrogen, and carbon compounds, the raw materials for propellant, breathable air, and construction feedstock that would otherwise be launched from Earth at enormous cost.
At Explural, our isotope and prospecting programs map helium-3 abundance across the lunar surface to identify where extraction first becomes viable, the groundwork for a clean, off-world fusion fuel supply chain.
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