Space

Prototype plant shows how astronauts could pull oxygen out of moondust

Prototype plant shows how astr...
Simulated moondust, showing before (left) the oxygen is removed, and (right) the mostly-metal makeup afterwards
Simulated moondust, showing before (left) the oxygen is removed, and (right) the mostly-metal makeup afterwards
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Researchers Alexandre Meurisse (left) and Beth Lomax (right) making oxygen out of lunar regolith
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Researchers Alexandre Meurisse (left) and Beth Lomax (right) making oxygen out of lunar regolith
A microscopic image of simulated moondust (lunar regolith)
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A microscopic image of simulated moondust (lunar regolith)
Simulated lunar regolith in the process of having oxygen extracted
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Simulated lunar regolith in the process of having oxygen extracted
Simulated moondust, showing before (left) the oxygen is removed, and (right) the mostly-metal makeup afterwards
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Simulated moondust, showing before (left) the oxygen is removed, and (right) the mostly-metal makeup afterwards
View gallery - 4 images

The Moon has no breathable oxygen – which obviously presents a hurdle for astronauts. There’s only so much we can take with us, so figuring out how to produce it there is crucial. Now, ESA researchers have created a prototype device that can make oxygen out of the most common thing on the Moon – dirt.

Moondust – more officially known as lunar regolith – has been studied extensively since samples were returned from the Apollo missions. Scientists were then able to reverse-engineer the stuff to figure out how future astronauts could put it to work, including by building bases out of baked bricks of regolith, and even using them to store heat for the long lunar nights.

These previous studies have revealed that oxygen is the most abundant element in lunar regolith, comprising 40 to 45 percent of its weight. The problem is, it isn’t exactly in a breathable form – the oxygen is locked away inside oxide minerals.

A microscopic image of simulated moondust (lunar regolith)
A microscopic image of simulated moondust (lunar regolith)

But researchers at the European Space Research and Technology Centre (ESTEC) have now developed a prototype oxygen plant that can extract usable oxygen from lunar regolith. The device uses a method called molten salt electrolysis, which involves adding the moondust to a bowl of molten calcium chloride salt, which has been heated to 950° C (1,742° F).

Even at this extreme temperature, the regolith remains solid. Then, an electrical current is applied to the mixture, which pulls the oxygen out of the dust. The molten salt acts like an electrolyte, allowing the oxygen to travel through it and then gather at an anode where it can be collected for use.

This version works as a proof of concept, and with further refining of the process a similar device could one day be sent to the Moon to help maintain a sustainable human presence there.

“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,” says Beth Lomax, an author of the study.

Researchers Alexandre Meurisse (left) and Beth Lomax (right) making oxygen out of lunar regolith
Researchers Alexandre Meurisse (left) and Beth Lomax (right) making oxygen out of lunar regolith

And oxygen isn’t the only potentially useful product to be extracted from the regolith. Once that vital gas is removed, the leftover stuff contains a mix of several different metals, which could be useful to astronauts for building.

“This is another useful line of research, to see what are the most useful alloys that could be produced from them, and what kind of applications could they be put to,” says Alexandre Meurisse, an author of the study. “Could they be 3D printed directly, for example, or would they require refining? The precise combination of metals will depend on where on the Moon the regolith is acquired from – there would be significant regional differences.”

The team plans to continue fine-tuning the design, with the hopes of getting a pilot plant up and running in the next few years.

Source: ESA

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6 comments
FB36
IMHO, non-stop gathering & processing moondust to get oxygen for astronauts would be extremely impractical! There was a news in this website a while ago about a new tech that easily separates CO2 back to O2 and carbon powder! IMHO, that is the real practical solution! Keep filtering CO2 from air & regenerating O2 from it (& throwing away carbon powder)! And since water can be already recycled, moon astronauts would only need food (which can be grown there too)!
Aross
Sounds interesting but there is no mention of what potentially harmful pollutants this process would produce.
neoneuron
The moon has no atmosphere for a reason. It has no Van Allen Belts to keep the solar wind from blowing it off the planet. A magnetic core is needed for this. The earth has one. That's the ONLY reason we have an atmosphere. Leave the moon alone, and stop trying to molest it. It's the only thing we haven't mutilated.
AladdinConnolly
@FB36
Obviously the would recycle their breathing. But the system would still need oxygen added becuase you cannot get 100% reuse of the oxygen that first got used by breathing. So this system would be a source for the part that needs to be topped up.
Douglas Rogers
The Moon is a ready source of materials for building rotating habitats. It has near real time communication with Earth. Materials are easily launched with rail guns.
buzzclick
Still lots of questions. This process seems energy intensive, and does not say how much is needed to extract the O2. How much solar paneling would be necessary? Or any other energy source? A nuclear plant? Does the whole lunar surface provide the ideal regolith, or select areas?