A fresh competition to reach the moon is developing between the United States and China. Unlike earlier efforts five decades ago, the aim now extends beyond brief landings to creating permanent bases that support long-term human activity on the lunar surface. The broader purpose is to test technologies on the moon that could support deeper space travel, such as missions to Mars.
A central approach involves in-situ resource utilization, or using local materials to generate essentials like oxygen, water, propellant, and building supplies. Producing these items on the moon itself would lower the weight of supplies launched from Earth and cut overall mission expenses. The focus shifts from transporting everything from our planet to learning how to sustain operations using lunar materials.
A primary task is obtaining oxygen from regolith, the loose layer of dust and rock fragments covering the moon. This material contains minerals such as plagioclase, pyroxene, and olivine, which include metal oxides binding oxygen with elements like silicon, iron, or calcium. Oxygen makes up roughly 40 to 45 percent of regolith by mass, yet it remains locked in solid form rather than existing as free gas.
To free the oxygen, the chemical bonds in these oxides must be broken. One technique under study is pyrolysis, which applies extreme heat to decompose the material and release gases. On the moon, concentrated sunlight would supply the necessary energy by focusing rays through mirrors or lenses to reach temperatures of several thousand degrees. The natural vacuum on the lunar surface would further aid the release of gases and lower energy demands.
The moon offers favorable conditions for this solar pyrolysis method. With almost no atmosphere, surface pressure stays extremely low, and sunlight reaches the ground without interference from clouds or air. Certain sites near the lunar south pole receive nearly continuous illumination. Researchers at the PROMES-CNRS laboratory in France have tested the concept using the large solar furnace at Odeillo, where mirrors concentrate sunlight up to ten thousand times to achieve temperatures above 3,000 degrees Celsius. Experiments with simulated regolith in a vacuum chamber have shown that heating the material to around 2,000 degrees Celsius causes oxides to vaporize and release measurable oxygen.
This process demonstrates a potentially simple and robust way to produce oxygen directly on the moon, supporting future exploration goals.
