A source of oxygen to support future colonies on the Moon may be found right underneath the feet of lunar settlers. The Moon’s regolith, or surficial rock and soil deposits, is 40% to 45% oxygen by weight and can be extracted with a molten salt electrolysis process developed at the European Space Research and Technology Simulated moondust before (left) and after (right) oxygen is extracted, leaving a metal alloy mixture. Source: Beth Lomax/University of GlasgowCentre in the Netherlands.

The method demonstrated in a laboratory-scale combines simulated lunar regolith with molten calcium chloride salt. The moon dust and electrolyte are then heated to 950° C and an electrical current is applied. The lunar material is converted into usable metal alloys as the oxygen released migrates across the salt and accumulates at an anode. It took 50 hours to extract 96% of the total oxygen, but 75% can be extracted in just the first 15 hours.

The potential to produce metals in situ in addition to oxygen could provide raw materials for construction or other extraterrestrial settlement applications. A pilot plant is planned for near-term demonstration of the technology prior to realizing the longer-term goal of operating a sustainable molten salt electrolysis facility on the Moon.