Oxygen is one of the most important resources for use in space exploration. Not only is it a complex piece of rocket fuel, but astronauts need to breathe anywhere outside the Earth’s atmosphere. This abundance is not a problem – it is widely available throughout the solar system. One place that is particularly prevalent is the lunar regolith, which is a layer of thin material that forms the surface of the moon. The trouble comes from one of the oxygen quirks of oxygen – it binds almost everything.
Regolith weighs about 45% oxygen oxygen, but is bound to materials such as iron and titanium. They must be separated in order to use both oxygen and the bonded material. And a British company, backed by the European Space Agency, has begun testing the technology to justify its potential effectiveness on the moon.
A company called Metalysis, already building closed machines on Earth that are capable of separating metals in oxygen-bound configurations. In an innovative move, the company used its process to extract oxygen and metals from the simulated lunar regolith, which is the best proxy here on Earth for real clay on the moon.
The experiment worked well, although some fine tuning would be needed to increase the amount of oxygen released. The process immerses the oxygenated material in the molten salt bath and then conducts an electric current through the combined salt and regolith. Electric charge allows oxygen to break its bonds with metals held in oxide form, and they are then free to move and condense on the charged electrode. Then a mixed metal powder is left behind.
This metal, if not properly equipped, can be used in deployment systems like 3D printing, but yet it is putting the cart before the horse. The experimental metallurgy, which takes place in a specialized chamber the size of a specialized shing machine, is starved of extraordinary power, and focuses primarily on the extraction of metal. All three characteristics must be modified if the process is to be used effectively in space.
Credit: Sheffield Research and Impact on YouTube
The chamber itself has to shrink to fit reasonably well with other space-bound equipment. Due to the severe lack of energy in situ on the moon, the power requirements will have to come down. And since oxygen is more valuable than metals on the moon, the process has to be tweaked with various reactants to get the most oxygen from the material.
Credit: ESA
Engineers of metallurgy and ESA still have some time to process their needs on the moon. NASA’s current ambitious Artemis program plans to put the man back on the moon in four years. If there is a system that can create rocket fuel and breathing gas for them on arrival, it would be a great step in securing future research missions from the lunar surface.
Learn more:
ESA – Converting lunar dust into oxygen
Space Ref – Turning Moon Dust into Oxygen
Discovery – Making air from lunar dust: Scientists build a prototype lunar oxygen plant
Lead Image Credit: ESA
