Lunar Helium-3 as a Long-Term Supplement

The Moon holds solar-wind helium-3 in its regolith; Kronos treats it as a genuine long-term supplement to breeder-made helium-3, not a near-term dependency.

Where lunar helium-3 comes from

For billions of years the solar wind has streamed helium-3 into the Moon's surface, implanting it in the regolith. With no atmosphere or magnetic field to deflect it, the Moon has accumulated helium-3 that Earth largely lacks. Concentrations are low — parts per billion by mass — so recovery means heating large volumes of regolith, but the total resource is large and, unlike Earth's legacy tritium stock, it is not shrinking.

How Kronos treats it — honestly

Lunar helium-3 is a real long-term supplement, but it is not the near-term supply. Recovering it requires lunar surface operations and transport that do not yet exist, and the programme deliberately does not depend on them. The breeder is the primary, proven-in-principle terrestrial source. Lunar helium-3 becomes relevant only later, as a way to expand supply beyond what a breeder fleet alone can produce, on a horizon of roughly the late 2030s and beyond.

• Solar wind implants helium-3 in lunar regolith over billions of years
• Concentrations are ppb-level but the total resource is large
• Recovery needs lunar operations that do not yet exist
• A long-term supplement to breeder helium-3, not a near-term crutch

The honest framing matters: the burner's fuel case stands on the breeder alone. Lunar helium-3 is upside, sequenced far behind the terrestrial supply, and nothing in the near-term plan assumes it.