The European Space Agency (ESA) has developed a prototype oxygen plant that has been set up in the Materials and Electrical Components Laboratory in Noordwijk, the Netherlands. Samples retrieved from the lunar surface confirm that lunar regolith is made up of 40–45% percent oxygen by weight, its single most abundant element. European Space Research and Technology Centre’s (ESTEC) oxygen extraction is taking place using a method called molten salt electrolysis, which involves placing regolith in a metal basket with molten calcium chloride salt to serve as an electrolyte, heated to 950°C. Read more for a video and additional information.
At 950°C, the regolith remains solid, but passing a current through it causes the oxygen to be extracted from the regolith and migrate across the salt to be collected at an anode. Plus, this process also converts the regolith into usable metal alloys. Best of all, the oxygen plant runs silently, with the oxygen produced in the process vented into an exhaust pipe, but will be stored after future upgrades of the system.
Having our own facility allows us to focus on oxygen production, measuring it with a mass spectrometer as it is extracted from the regolith simulant. Being able to acquire oxygen from resources found on the Moon would obviously be hugely useful for future lunar settlers, both for breathing and in the local production of rocket fuel,” said Beth Lomax of the University of Glasgow, whose PhD work is being supported through ESA’s Networking and Partnering Initiative, harnessing advanced academic research for space applications.