Artist impression of activities in a Moon Base. Power generation from solar cells, food production in greenhouses and construction using mobile 3D printer-rovers.
The moon is covered in fine, delicate dust called regolith which sticks to absolutely everything and causes all sorts of technical problems. But it is an abundant resource, and plans for making use of it include melting it with lasers to use for 3D printing or packing it into bricks to build habitats. Now, the European Space Agency (ESA) has come up with a different use for the tricky substance: Turning it into oxygen which could be used by lunar explorers for breathing and for the production of fuel.
Moon regolith is known to contain about 40 to 50% oxygen by weight, but it is bound in the form of oxides so it’s not immediately usable. Researchers at the European Space Research and Technology Centre (ESTEC) have been investigating ways to extract this oxygen using a technique called molten salt electrolysis. The regolith is placed in a metal basket along with molten calcium chloride salt and heated to a high temperature, then an electric current is passed through it so the oxygen can be extracted. A bonus of this method is that it also produces usable metal alloys as a by-product.