How can astronauts live safely on the Moon over extended periods of time? How can dwellings be built there and how do we obtain the air we need to breathe? Can it realistically be done or is it all just science fiction? Scientists have been pondering these questions for years. Dr. Klaus Slenzka, Head of Life Sciences at OHB, talks in an interview about the feasibility, possibilities and myths of living on the Moon.
The last time a man set foot on the Moon was 50 years ago. Describe to us the environment the astronauts of the Apollo 11 mission found when they landed on the Moon.
Klaus Slenzka: It is important to know that Moon dust is very fine and extremely sharp-edged. During the Apollo missions the zippers fitted to the space suits were broken after being used twice. This is of course a major problem for life there.
It does not exactly sound like a hospitable planet ...
The Moon consists of 40 percent oxygen. If we are able to tap this oxygen, we will at least have something to breathe.
And how do we get the oxygen?
Currently, research is being carried out into various methods (pyrolysis, methane reduction, etc.) and particularly also a method using hydrogen reduction, which involves splitting chemical compounds at high temperatures by applying hydrogen. Using this method on the Moon means heating lunar rock to about 1,200 degrees. Then the substances that are released must be bound. 1,200 degrees is still quite a moderate temperature. Other processes require temperatures of 1,600 or even more than 2,000 degrees Celsius. And we also need hydrogen. Using these ingredients, we can generate water and break it down into the chemical components oxygen and hydrogen by means of electrolysis. That’s how we could obtain oxygen. ESA is currently working on this method. The challenge we face stems from the fact that we would have to transport the hydrogen from the Earth. So, the question is, how do we get it to the moon?
Are there any resources on the Moon that humans could use to facilitate life there?
The Moon is believed to hold reserves of water. We could very well find ice in the huge craters that lie in the eternal darkness. And that brings us to the next problem, namely, darkness and temperatures close to 0 degrees Kelvin, in other words around minus 270 degrees Celsius. What machines would work under these conditions to tap the ice? And where would the power come from? These are questions that we need to answer. We face a huge technical challenge which I’m sure will take another one or two decades to solve.
Are there other ways of gaining oxygen?
In the Life Sciences Department, we are naturally looking for biological answers. We are using special bacteria, blue and green algae, which - put simply - can eat the metal oxides on the moon and split them. That’s how we could obtain oxygen. NASA has already managed to split titanium-iron oxides into titanium-iron compounds and oxygen using extremophilic microorganisms. This procedure is called “biological in-situ resource utilization” and means using the prevailing conditions and biological substances. Here, too, we must bear in mind that we would need specific bioreactors on the moon to produce oxygen. This, in turn, would require the transportation of the necessary building materials. Here, too, we would have to determine where the energy comes from. But it would not be impossible.
And so the astronauts would then grow a vegetable garden to supply themselves with what they need?
I’m afraid it’s not that simple. We know that the sharp-edged moon dust destroys the root hairs of plants. And this would need to be prevented! Here in the laboratory we are using samples that are modelled on real Moon dust and have managed to transform the dust into soil in which we can grow plants. To do this, we combine communities of bacteria and green algae with Moon dust. These grow around the sharp particles, generating soil in which higher plants can grow.
Without water there is no life. How do we lay our hands on this precious substance?
This will depend on how much hydrogen we can transport to the Moon or possibly extract there. I assume that we will have to transport most of the hydrogen to the moon and recycle it almost fully. After all, we will need regular replenishments. Closing the gap in the cycle is the big challenge. Science still has a long way to go before achieving this.
What other areas is the Life Sciences Department exploring?
We have made considerable progress in 3D bio-printing. Biocompatible implants are derived from human tissue such as stem cells or cartilage tissue using 3D bio-printing. This is definitely a market with a great future in the field of regenerative medicine and also an important prerequisite for exploration on the Moon and Mars.
How realistic is it to expect that we will soon be able to live permanently on the Moon?
It certainly won’t be soon as we still have too many challenges, especially technical ones, such as artificial gravity, to overcome. But one day it will definitely be more than just science fiction.