The European Space Agency conducts research within the framework of the Melissa project - looking for opportunities to create artificial ecosystems on other planets. Simply put, scientists want to figure out how to make other planets habitable for humans. For example, urine and excrement can be processed into fertilizers, you just need to choose the right plants, the Swiss newspaper writes.
Grace Crain's right forearm has nine circles in one line. One of them is Earth, next to it is Mars. A 25-year-old energetic American woman got a tattoo of the solar system.
Since childhood, Grace has been fascinated by space. This is not surprising, because her father is an astrophysicist who developed algorithms for American satellite companies and from an early age took his daughter to scientific conferences.
Since September, Grace Crane has been doing research on behalf of the European Space Agency (ESA) at the Swiss Higher Technical School (HTS) in Lindau. Her work is part of the Melissa project, which is looking for opportunities to create artificial ecosystems on other planets. Simply put, scientists want to figure out how to make other planets habitable for humans.
Urine from HTS toilets
The key word here is recycling. The goal is to create a perfect ecological cycle in which nothing goes to waste. “After all, sending humus to another planet is terribly uneconomical,” says Grace.
Therefore, it works with what accumulates in a completely natural way: with human urine and excrement. At the moment, she is trying to establish what composition of urine is beneficial for plant growth. Urine is collected in the toilets of the Water Research Institute at the HTS. It is processed into liquid fertilizer "Aurin".
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“Urine contains a lot of salt for natural reasons. As we consume more and more salt, our urine becomes more salty,”says Grace. This is a problem as many plants do not tolerate salt well. What if the goal is to create an ideal cycle of substances? One option is to grow salt-loving plants.
One type of salt, perchlorate, is found in high concentrations in Martian sand. “Plants do not react to it, but it is poisonous to humans,” explains Grace. So the scene from the Hollywood movie The Martian, where Matt Damon, abandoned on Mars, grows potatoes in sand mixed with feces, has little to do with reality. The only alternative is the clean disposal of human excreta.
60 rats are equal to one person
The next problem in space is location, as odd as it sounds. Temperature drops on Mars day and night can be up to 100 degrees, so the plants will have to be grown in greenhouses. “They will need optimal plants to grow that can provide a balanced diet,” says Grace. Soy is recognized as one of these optimal plants.
The next problem is carbon dioxide, which we humans constantly exhale. Plants will have to convert it back into oxygen, otherwise the astronauts will suffocate sooner or later. To investigate these processes, the European Space Agency has built a prototype of a special facility in Barcelona. In it, oxygen must be produced by algae. The sealed facility contains 60 rats, which together consume approximately the same amount of oxygen as one person. True, there is an idea to artificially heat Mars in order to arrange open fields there. But Grace finds her unrealistic.
Successful experiments
But it is quite possible to grow plants. In January, for the first time, the Chinese satellite Chang'e-4 managed to achieve the germination of cotton seeds. And the German Center for Aviation and Cosmonautics in early December launched a greenhouse satellite with tomatoes and other vegetables on board into low-earth orbit.
“During the flight, the effect of weightlessness on plant growth is being investigated,” says Grace. Experiments with plants were also carried out on the ISS. “Plants also had a psychological effect on astronauts, and they reminded many of nature in this high-tech capsule,” Grace says. A similar effect can be observed on Earth: if you put plants in a large office, then employees become more comfortable there.
Psychological barrier
According to Grace Crane, the settlement of Mars in the coming decades is quite possible. "It sounds like science fiction, but we live in an era where more and more things are becoming reality." She hopes that future exploration of other planets will serve science, not commerce: "A hotel on Mars is completely unnecessary!" But she believes that space hotels will appear in which it will be possible to spend a couple of days in zero gravity.
Whether humans will settle on Mars in the near future or not, Grace sees her research as meaningful. She is motivated by a desire to better understand the complex ecological relationships on Earth. This knowledge will be useful here as well.
"For example, we have a lot of problems with chemical fertilizers, and fertilization from human excreta could help solve many of the problems." According to her, there are technological possibilities for this. "However, many have a psychological barrier, because in the Middle Ages, many people died due to human feces in drinking water."
Jonas Gabrieli