ESA plant shows how astronauts could extract oxygen from moondust

the european space agency (ESA) has opened a plant in the netherlands designed to extract oxygen from moondust. the oxygen extraction uses a method called molten salt electrolysis, which involves placing the material in a metal basket with molten calcium chloride salt to serve as an electrolyte, heated to 950°c. 

this extracts the oxygen trapped within the material and also converts the dust into usable metal alloys. researchers hope that this prototype will lay the foundations for one day building a self-sustained base on the moon. making oxygen in space would allow astronauts to manufacture their own breathable air and also produce rocket fuel.

oxygen and metal from lunar regolith
images courtesy of ESA

‘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,’ comments 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. ‘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.’

microscopic image of moondust simulant

this molten salt electrolysis method was developed by UK company metalysis for commercial metal and alloy production. beth’s PHD involved working at the company to study the process before recreating it at the european space research and technology centre, estec, based in noordwijk in the netherlands.

‘at metalysis, oxygen produced by the process is an unwanted by-product and is instead released as carbon dioxide and carbon monoxide, which means the reactors are not designed to withstand oxygen gas itself,’ explains beth. ‘so we had to redesign the estec version to be able to have the oxygen available to measure. the lab team was very helpful in getting it installed and operating safely.’

moondust simulant undergoing oxygen extraction

the oxygen plant runs silently, with the oxygen produced in the process is vented into an exhaust pipe for now, but will be stored after future upgrades of the system. the ultimate aim would be to design a ‘pilot plant’ that could operate sustainably on the moon, with the first technology demonstration targeted for the mid-2020s.

project info

organisation: european space agency