Helium-3 (He-3) is a light, non-radioactive isotope of helium with two protons and one neutron (common helium having two neutrons).
He-3 is used as fuel for fusion reaction engines of starships.
Extraction from Extraterrestrial SourcesEdit
Materials on the Moon's surface contain Helium-3, with higher concentrations in permanently shadowed regions. Exploration of the moon and mining lunar regolith, piggybacked onto larger mining and development operations provided initial He-3 supplies.