One of the significant challenges for putting humans for long durations on the Moon or other planets is in getting enough breathable air. ESA scientists have begun to produce oxygen out of simulated moondust. A prototype oxygen plant has been set up in the Materials and Electrical Components Laboratory of the European Space Research and Technology Center in the Netherlands.
The team says that having the faculty allows it to focus on oxygen production and measure it with a mass spectrometer as it is extracted from the regolith simulant. Being able to get oxygen from resources found on the Moon will be a huge step in supporting lunar colonies and exploration.
The oxygen can be used for other breathing and for the local production of rocket fuel. The team says that they have a facility in operation that is looking into fine-tuning the product methods, reducing operating temperature, and eventually designing a version that can be flown to the Moon and operated there.
Samples of regolith that were brought back from the Moon have confirmed that regolith is 40-45% oxygen by weight. Oxygen is the single most abundant element in the regolith. The catch is that the oxygen is bound up chemically as oxidized in the form of minerals or glass.
The oxygen extraction method used is called molten salt electrolysis. It involves putting the regolith in a metal basket with molten calcium chloride salt to serve as an electrolyte. It’s heated to 950C, and an electrical current is passed through, allowing the oxygen to be extracted. The process also converts regolith into usable metal alloys. The team says that their oxygen plant runs silently with the oxygen produced vented into an exhaust pipe for now, but future versions will store the oxygen. The first tech demos are targeted for the mid-2020s.