This is how we can make oxygen on the moon

It’s been 50 years since humans were last on the moon, but NASA and the European Space Agency have plans to try again in not that many years. Some are also talking about using the Moon as a way station for further space travel.

So there is the problem that the moon does not have an atmosphere with oxygen like we have here on our planet. To be able to breathe there, you have to carry oxygen with you the long, energy-consuming way from Earth. Unless the oxygen you need can be produced on the Moon.

– In principle, it is possible to produce oxygen on the Moon, says senior researcher Karen Cindy Ossen at Sintef.

– The moon is covered with sand, and this sand consists of minerals and oxygen. If you can get the oxygen out of there, you can make the oxygen to breathe, Osin says.

But that doesn’t mean it’s easy.

Many of the technologies you imagine being in use aren’t fully developed on Earth, Ossen says on the podcast cleverly explained.

The moon as a gas station

Osen does not believe that the air he breathes is the most important driving force for the development of this technology.

– At least the importance of producing oxygen as fuel for ships that go into space and use the Moon as a “gas station,” according to Osin.

Getting out of Earth’s gravitational field requires a lot of energy and fuel. If you can fill oxygen on the moon and use it in fuel cells, you can travel farther.

– The Moon’s gravitational field is only one-sixth that of the Earth’s, so you need much less fuel to take off from the Moon, Osin explains.

The Earth’s crust is also full of oxygen

Although most of us probably think primarily of the air we breathe when it comes to oxygen, there is also plenty of oxygen in the soil below us. In fact, oxygen is the most common element in the Earth’s crust. Almost half of the Earth’s crust, 47 percent, is made up of oxygen.

On the Moon, the oxygen level is slightly lower, but not by much. More than 40 percent of the moon’s crust is made up of oxygen.

This oxygen binds to minerals with other elements in what are called oxides. Quartz, for example, the second most common mineral in the Earth’s crust, is also called silicon dioxide (SiO).₂).

– When we separate a metal from an oxide found on Earth, for example iron or silicon, then this is the metal we are interested in. Carbon is a very good medium for stealing oxygen away from the metal, but then you get carbon dioxide₂. We don’t want that, at least not on the moon, Ossen says.

co₂ We want to have as little as possible on Earth, too. Therefore, the technology that needs to be developed to extract oxygen from the moon sands is also very important here.

– We, who are doing research on mineral production, are doing a lot of research on how to reduce carbon dioxide₂– emissions from metal production, and then this will be a new method, says researcher Sentev.

Electrolysis separates the oxygen from the metal

To achieve this, a process called electrolysis can be used. In short, it is about using electricity to break down metals into their individual components.

– There are many minerals that are synthesized in a similar way on planet Earth today, says Osin.

In order to stick to the moon’s sand, it must be placed in a liquid, what is called an electrolyte, which is heated to perhaps 1,000 degrees. Then they dissolve and turn into charged atoms – ions. When a positive and negative electrode is placed there, ions will be drawn toward each electrode.

The negatively charged oxygen atoms will move towards the positive electrode. There they will turn into oxygen gas as they give up electrons when the current is turned on.

It must be able to pick up oxygen

You’re not on target even if oxygen gas starts to appear at one electrode.

Oxygen capture is a separate technology in itself. This is something we have experience at Sintef. Then you have to use a membrane, a filter, that can separate the different gases from each other, Ossen says.

– We’re already doing a lot of research on this in terms of fuel cells and carbon dioxide₂-intercept, but there is also a separate technology that must be developed and adapted for exactly this purpose. It’s not on the shelf either.

So there is enough research before one can produce oxygen to breathe on the moon. Neither a filter to capture oxygen nor an electrode to capture it has been developed yet. And as if that wasn’t enough, it’s also not a given that what you achieve on Earth will work on the Moon.

– The situation there is completely different. For example, there is a void there because there is no atmosphere. The liquid released into space would evaporate very quickly, much faster than here on Earth. This electrolyte, for example, that if you open it up and remove the cap, Ossen explains, will probably disappear.

The moon also has a sixth of our gravity. This can cause both liquids and gases to behave differently.

– In addition, the lunar day is very hot. During the day the temperature can be over 200 degrees, while the moonlit night can be minus 100. These are extreme situations that make it difficult. Ossen says there are many of these challenges that make it demanding.

If you succeed

But if they get it right, at least no one on the moon will have breathing problems.

– In 20 grams of sand there is enough oxygen to keep you alive for 20 minutes. The researchers found that in some areas the sand layer is twelve meters deep, so there is a lot of sand there, Osin says.

With the right technology, sand can also be used for other things. For example, for building materials.

– There is a lot of sand and stone there, and there is a lot of research into making cement and concrete from that sand.

– And there are a number of areas where ice is found, and you can also take advantage of that. Either by just dissolving it, Osin says, or also by extracting hydrogen and oxygen from the water.

If they don’t become completely self-sufficient, they will at least get by in some way.

– Maybe you can build houses out of the concrete you make. If you can produce oxygen, you can breathe and use it for fuel cells. There are also many minerals in the sand that you can take advantage of, in addition to oxygen gas, Ossen says.

Not just science fiction

Much of this may sound like science fiction, Osen admits. But just as past moon programs have led to breakthroughs that we benefit from here on Earth, she also believes that searching for moon sands can produce tangible results that we can all enjoy.

– We work a lot in our environment on recycling, the so-called urban mining, where you extract metals from scrap – what we call important raw materials for which there is little and which also has a great economic benefit.

– What we learn about these electrolysis processes, about the production of oxygen-free metals, can also be indirectly transferred to very socially useful research on Earth, Ossen says.

It does not allow itself to be persuaded to estimate the time when it will be possible to produce oxygen on the Moon.

– Based on what I know about the many technological challenges, we can probably hope that this will happen in 20-30 years. But it will depend on some technological breakthroughs within, among other things, material production and gas capture.

The article was first published on Gemini