Lunar resources

Lore & Background

The Moon bears substantial natural resources that could be exploited in the future, including processable materials such as volatiles and minerals, along with geologic structures like lava tubes. Resource mapping and sample-return missions have enhanced understanding of the potential for lunar ISRU, though an assessment in 2019 concluded that knowledge was not yet sufficient to justify large financial commitments. The determination of resource availability will drive the selection of sites for human settlement.

Lunar materials could facilitate continued exploration of the Moon, scientific and economic activity in cislunar space, or be imported to Earth. Regolith is the easiest product to obtain, providing radiation and micrometeoroid protection as well as construction material. Oxygen from regolith oxides can be a source for metabolic oxygen and rocket propellant oxidizer. Water ice can provide water for radiation shielding, life-support, oxygen, and rocket propellant feedstock. Trace amounts of volatiles such as methane, ammonia, carbon dioxide, and carbon monoxide may also be present in permanently shadowed craters.

The Moon is known to be poor in carbon and nitrogen, and rich in metals and oxygen (bound in oxides), but their distribution and concentrations are still unknown. Solar power, oxygen, and metals are abundant. Elements known to be present include hydrogen, oxygen, silicon, iron, magnesium, calcium, aluminium, manganese, and titanium. The oxygen content in the regolith, bound in oxides, is estimated at 45% by weight. Trace gases in the lunar exosphere are unlikely to be useful for ISRU due to very low concentration.

Reader's Guide

Lunar resources are significant because they could enable sustained human presence on the Moon and reduce reliance on Earth-supplied materials. The ability to extract oxygen, water, and metals in situ would lower the cost and risk of lunar exploration and potentially support economic activity in cislunar space. However, as of the 2019 assessment, knowledge of resource distribution and concentrations was not yet sufficient to justify large financial commitments for an ISRU-based campaign. The selection of landing sites for human settlement will depend on determining resource availability. While solar power is abundant at the lunar poles, nuclear power systems like Kilopower or RTGs could provide reliable energy during the two-week lunar night. The extraction of oxygen from regolith requires high energy input, and the production of nuclear fuels like helium-3 remains theoretical due to the lack of controlled fusion. Overall, lunar resources represent a promising but still uncertain frontier for space exploration and economic development.

Did You Know?

• The total mass of the Moon's exosphere is roughly 25,000 kilograms with a surface pressure of 3×10−15 bar.
• Helium-3 abundance in lunar regolith is higher than on Earth, but nuclear fusion has not yet been employed in a controlled fashion releasing net usable energy.