European startup builds oxygen-making machine for 2025 moon mission

A European startup is perfecting technology that will be sent to the moon to make oxygen from lunar soil as part of a 2025 European Space Agency (ESA) demonstration mission.

Belgium-based Space Applications Services is building three experimental reactors under a contract with ESA announced on Wednesday (May 12). The reactors will be used to fine-tune the oxygen-making process to be tested on the moon as part of the planned in situ resource utilization demonstration (ISRU) mission in 2025.

The oxygen-making machine will rely on the FFC Cambridge process, originally developed in the late 1990s for direct extraction of titanium from titanium oxide, which can be found in nature in the minerals rutile and anatase. The process — named after its inventors George Chen, Derek Fray and Thomas Farthing, and Cambridge University in England where they all worked —uses electrolysis to separate the pure metal from the ore.

In the lunar environment, the technique will split lunar regolith, which is known to consist of up to 45% oxygen, into metal alloys and pure oxygen. The moon dirt in this process is used as a cathode, the electrode through which an electric current enters the electrolytic cell, releasing oxygen in the process. 

While hauling oxygen supplies from Earth works just fine for short-duration space trips or missions that can be easily resupplied, locally made oxygen will be key for maintaining longer-term human presence on any celestial body, exploration advocates say. The metal alloys left after the oxygen extraction will not be wasted, either. In the future, they could be used to manufacture components for a moon base or a Martian station, for example with 3D printing.

In addition to the FFC Cambridge method, Space Applications Services is also looking into another technique for oxygen extraction from lunar soil: the hydrogen reduction of ilmenite. Ilmenite is a titanium-rich ore found in some areas of the moon. The reduction technique involves baking the regolith in a closed container together with hydrogen gas. In the presence of heat, the oxygen from the ilmenite reacts with the hydrogen and forms water vapor, which can then be split into oxygen and hydrogen.

In addition to sustaining the crew, the oxygen and hydrogen manufactured on the moon could be used as fuel for missions venturing deeper into the solar system, for example to Mars.

Space Applications Services has recently completed an early design phase of the gear for the 2025 mission, which will for the first time demonstrate end-to-end production of both oxygen and water from local lunar resources, company representatives said in a statement.

ESA's plan is to buy all services for the ISRU mission from commercial providers. That includes communication, transportation and services needed to operate the mission.