European researchers are working on a system that can churn out breathable oxygen from simulated samples of moon dust.
“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,” explained Beth Lomax, a chemist from the University of Glasgow, in an European Space Agency (ESA) press release.
Lomax, along with ESA research fellow Alexandre Meurisse, are currently plugging away at a prototype that could eventually lead to exactly that: oxygen production from lunar dust. They’re currently testing their system at the Materials and Electrical Components Laboratory of the European Space Research and Technology Centre (ESTEC), which is based in Noordwijk, the Netherlands.
Their prototype is working, but adjustments will be required to make it suitable for use on the Moon, such as reducing its operating temperature. Lomax and Meurisse are currently working with simulated moon dust, but they’re hopeful their approach will work on the real deal.
Indeed, samples of lunar dust, known as regolith, returned to Earth during the Apollo missions were found to consist of around 40 to 45 percent oxygen, according to the ESA. The ESTEC scientists are devising a technique that can coax this oxygen out from the dust, in what might seem like alchemy to the casual observer.
Oxygen in the regolith is stubbornly packed as oxides, which form as minerals or glass within the dust. Some crafty chemistry is required to pull the oxygen out, as described by the ESA:
ESTEC’s oxygen extraction is taking place using a method called molten salt electrolysis, involving placing regolith in a metal basket with molten calcium chloride salt to serve as an electrolyte, heated to 950°C. At this temperature 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. As a bonus this process also converts the regolith into usable metal alloys.
This process was developed by Metalysis, a UK-based company that’s using the technique to produce metals and alloys. Lomax collaborated with Metalysis while she was working on her PhD, and now she’s leveraging the concept at ESTEC.
Because Metalysis treats the resulting oxygen as an unwanted byproduct, the system had to be tweaked such that the researchers could capture and measure any oxygen extracted from the samples. As it stands, the system is venting oxygen into an exhaust pipe, but future versions will capture and store this oxygen for the long term.
Interestingly, ESTEC is not treating the metals as an unwanted byproduct. The team is currently looking into various ways of exploiting these metals in a lunar environment, such as transforming them into compounds for 3D printing.
All this work is a lead-up to a system that could function on the Moon. The ESTEC scientists are aiming to have a functional, Moon-ready version by the mid 2020s. Equipped with such a device, future lunar explorers and colonists will be able to breathe a bit easier.
Moon dust may be seen as a valuable resource now, but when astronauts first went to the Moon, NASA was extremely anxious about the potential dangers posed by lunar powder. They weren’t wrong to worry: Subsequent research has found simulated moon dust can kill human cells and alter DNA.