The German Centre for Aviation and Aerospace (DLR) has been working on the EDEN-ISS project in Antarctica for some time now to find out how food production may look in life-threatening conditions in the future. The results of last year's work were recently announced and a new concept of a space greenhouse was introduced.
At the EDEN-ISS Antarctic Greenhouse, researchers are conducting experiments in adverse conditions for humans and plants to produce food for future space missions, intending to enable astronauts to use this technology on Mars and the Moon. Cultivated plants do not need any soil and are fed with a special raster, and lighting is provided by artificial light sources.
The DLR scientist Dr. Paul Zabel was in Antarctica at the test station from the end of 2017 to the end of 2018 and grew plants in permafrost conditions. According to his team's report, they were amazed at how much they were able to harvest and that they needed less energy than originally expected.
At the presentation of the results of the EDEN-ISS project (worth €5 million), the scientist said: "In nine and a half months, we produced 268 kg of food on only 12.5 square meters of floor space, including 67 kg of cucumbers, 117 kg of salad and 50 kg of tomatoes. The quality of the vegetables was flawless, they had a high nutrient content and were free from harmful substances.
Zabelle brought hundreds of samples and data from Antarctica, some of which are still being studied. What was immediately discovered on the spot: fresh greenery significantly improved the mood of nine station workers. "The taste of fresh food and the smell of herbs were very much accepted," Zabel said.
The average energy consumption of the greenhouse was 0.8 kW per square meter of treated area, which is twice less than previously estimated - for greenhouses it was previously estimated at 2.1 kW per square meter. "This is an important aspect of further space projects, which gives us confidence in the success of this idea," said Dr. Daniel Schubert, EDEN-ISS project manager at the DLR Space Systems Institute.
On average, he spent three to four hours a day growing plants. Two-thirds of his time was devoted to the operation and maintenance of greenhouses and another third to sowing, harvesting, and maintenance. "In a future space greenhouse, the amount of valuable time spent by astronauts should be significantly reduced," said Zabelle.
The design of the greenhouse is folding, and its size fits into the fairing of the rocket launch vehicle Falcon 9. The greenhouse can provide astronauts with enough space to grow plants on the Moon and Mars. "The area under cultivation is about 30 square meters, almost three times the area of the Antarctic greenhouse container. With this system it is possible to grow about 90 kg of fresh food per month, which corresponds to a half kilogram of fresh vegetables per day per astronaut, for a team of six people," explains Schubert. Also, a biofilter system can be connected to the greenhouse to produce fertilizer from bio-waste and urine.
"For future long-term space flights, food must be grown locally. EDEN-ISS has proven the feasibility of building a space greenhouse in Antarctica and has shown that this technology can also be used to produce food on the Moon and Mars," says DLR's Executive Director for Space Research and Technology, Professor Hansjoerg Dittus. "The concept of a space greenhouse presented today is a valuable foundation on which we want to build further research.