Helium-3, an isotope of helium distinguished by a paucity of neutrons, constitutes one of the most exorbitantlyexorbitantly/ɪɡˈzɔːrbɪtəntli/L3极其昂贵地；价格高得离谱地in a way that is unreasonably high or excessive, especially in price or cost priced materials on Earth, with a single litre commanding approximately $2,000. Its primary contemporary source, however, is decidedly unconventional: the radioactive decay of tritium within nuclear arsenals, a tightly controlled supply chain that yields tens of thousands of litres annually. Yet burgeoningburgeoning/ˈbɜːrdʒənɪŋ/L3迅速增长的；蓬勃发展的growing or developing rapidly; flourishing demand from quantum computing and nuclear fusion research threatens to outstrip this constrained output, prompting a search for alternative reservoirs. Consequently, attention has pivoted to celestial bodies, specifically the Moon, where Apollo-era regolith samples suggest comparatively elevated concentrations of this rare gas.
The extraction of lunar helium-3, however, presents formidableformidable/ˈfɔːrmɪdəbəl/L3难以克服的；令人敬畏的inspiring fear or respect through being impressively powerful, intense, or difficult engineering and economic challenges. Interlune, a Seattle-based venture co-founded by Apollo 17 astronaut Harrison "Jack" Schmitt, aims to deploy autonomous excavators to scoop and process vast quantities of powdery regolith, potentially requiring the movement of hundreds of thousands of tonnes to obtain a single kilogram. Concentrations, estimated between a few parts per billion and roughly twenty, remain uncertain; moreover, Apollo samples may have lost volatiles during their return to Earth, skewing predictive models. As Paul Burke of Johns Hopkins Applied Physics Laboratory cautions, understanding the precise spatial distribution and accessibility of these deposits is imperativeimperative/ɪmˈpɛrətɪv/L3至关重要的；必要的absolutely necessary or required; of vital importance before any commercially viable operation can commence.
Notwithstanding these obstacles, corporate interest is intensifying. Interlune has secured a $300 million agreement with a Helsinki-based quantum computing firm to supply 10,000 litres of helium-3 annually between 2028 and 2037, and has tested extraction equipment in parabolic zero-gravity flights. Astrotech Corporation, meanwhile, plans to leverage a SpaceX Starship for lunar operations, heating regolith to release the gas. That said, terrestrial alternatives are being pursued: Pulsar Helium is investigating a site in Minnesota with concentrations around 12 parts per billion, accessible via conventional drilling. As one geochemist dryly observes, Minnesota is considerably more accessible than the Moon, though the ultimate economic viability of either approach remains contingent upon technological maturation and market dynamics.
