EDEN-ISS: Substantial vegetable harvest in Antarctica

No, luckily the climate in Antarctica is still inhospitable. And this is precisely why the German Aerospace Center (DLR) set up the EDEN-ISS greenhouse there in 2018. This is because food production of the future and future space missions are being researched in the immediate vicinity of the German Antarctic Neumayer III Station. In the meantime, the winter crew from the Alfred Wegener Institute (AWI), including DLR researcher Dr Paul Zabel, has spent a year surrounded by constant ice. The team presented the results on 23 August: There was an unexpectedly rich harvest. According to Zabel:

“In just nine and a half months, we produced a total of 268 kilograms of food on just 12.5 square meters, including 67 kilograms of cucumbers, 117 kilograms of lettuce and 50 kilograms of tomatoes.”

Before his trip, by the way, Zabel had been smart enough to look into artificial vegetable cultivation in Dutch greenhouses. Zabel adds:

“The taste of the fresh vegetables and their smell left a lasting impression on the winter crew and had a visibly positive effect on the team’s mood throughout the long period of isolation.

A correlation that is now also being researched from a psychological perspective.

Lower energy consumption than expected

Additionally, the scientists were surprised that they needed much less energy than they had initially expected. The average power consumption during the analog Antarctic mission was 0.8 kilowatts per square meter of cultivated area. It was consequently less than half as much as previously assumed for aerospace greenhouses, which were estimated at 2.1 kilowatts per square meter.

“This is an important aspect for a subsequent space venture and gives us confidence about the future of this idea”.

… says Project Manager Dr. Daniel Schubert from the DLR Institute of Space Systems. Aside from that, he stresses the potential and useful addition to space food that can be supplied by the earth:

“In one year in the Antarctic we have seen very clearly how enough food can be produced in a very small space in order to supplement the food of a crew of six by a third with freshly grown food.”

High workload should be reduced

Notwithstanding this, the researchers still see some potential for development. Because in order to save valuable astronaut time, the amount of work required for support and maintenance has to be significantly reduced in the future. Zabel needed an average of three to four hours a day in order to cultivate the plants:

” I spent about two thirds of my time operating and maintaining the greenhouse technology, another third on sowing, harvesting and maintenance. In the future, a space greenhouse needs to significantly reduce the amount of  an astronaut’s valuable time.”

On top of that, the time required for experiments was about four to five hours per day. The aeroponic cultivation system, i.e. nutrient solution without soil, enabled the plants to flourish successfully. Some pumps caused problems in the intervening period and the biofilm in the nutrient tanks were unexpectedly high, yet these problems could be remedied.

New EDEN-ISS designed for the Falcon 9 rocket

Based on the results and experiences of the EDEN-ISS project, a new design concept for a space greenhouse has now been developed. This greenhouse is fairly compact in its design so that it can be launched aboard a Falcon 9 rocket. At the same time, it is expandable and large enough to provide sufficient food for the astronauts on the moon or on Mars. “The area used for cultivation is around 30 square meters, almost three times the size of the Antarctic greenhouse container. Using this system, around 90 kilograms of fresh food could be grown per month, which corresponds to half a kilogram of fresh vegetables per day and per astronaut if six astronauts are present,” Schubert explains.

The concept may also be combined with a biofilter system (C.R.O.P.). Its purpose is to produce a fertilizer solution for plant cultivation that is able to be utilized from biowaste and urine directly. This makes the greenhouse concept almost a fully bio-regenerative life support system for future habitats. Prof. Hansjörg Dittus, DLR Executive Board member responsible for space research and technology, elaborates further:

“The newly proposed concept for a space greenhouse is an invaluable foundation on which we intend to further expand our research work.”

EDEN-ISS is open to research teams worldwide

Following Paul Zabel’s return to Germany, the Antarctic greenhouse was initially in “sleep mode”. Previously, the DLR team had maintained all systems on site in January 2019 and completely overhauled the container. The Bremen researchers then woke the system up from its sleep at the beginning of May using a remote control system and powered it up again. A seed sown at an earlier stage began to flourish.

“This step served to test another space scenario. Because a provisional greenhouse is expected to arrive before the astronauts and ideally start its operation remotely.

… DLR researcher Schubert explains and he adds: “The test run was a complete success. Now the current AWI winter crew is continuing to operate the greenhouse with strong support from the Bremen Control Center, from where we monitor as much as we possibly can from a distance. The procedures developed last year are currently proving their worth in minimizing the crew’s workload and simplifying procedures as far as practicable”.

The greenhouse is also now available to various research groups worldwide who are interested in conducting plant cultivation experiments in the Antarctic.

“As one of the first new collaboration partners, the American space agency NASA has already sent us original NASA salad seeds, which are also cultivated on the International Space Station ISS and now thrive here in Antarctica,” Schubert adds.

Findings are interesting for global food production

The frozen continent of Antarctica is one of the most exciting research regions in the world. “It is primarily here that we gather data on global climate change and Antarctic biodiversity. However, the greenhouse is an excellent example of how we can conduct research at Neumayer Station III on other important questions for the future. After all, we have a lot in common with space travel when we travel to regions that are hostile to humans in order to gain new insights. At the same time, the permanent supply of fresh fruit and vegetables has a very positive side effect on our winter crew this year once again,” says Prof. Antje Boetius, Director of the Alfred Wegener Institute, who, during her stay at the station, was able to convince herself of the wonderful flavor of a juicy giant radish from the greenhouse. The cultivation of vegetables is consequently also interesting for future missions by the research icebreaker Polarstern.

Moreover, global food production is one of the central challenges facing society in the 21st century. An ever-increasing world population and the simultaneous upheavals caused by climate change call for new ways of cultivating crops even in climatically unfavorable regions. A self-contained greenhouse enables harvests that are independent of weather, sun and season, as well as lower water consumption and the elimination of pesticides and insecticides for deserts and regions with low temperatures, as well as for space missions to the moon and to Mars. In the EDEN-ISS project, such a model greenhouse for the future is undergoing long-term testing under extreme Antarctic conditions.

EDEN-ISS partners

EDEN-ISS is developed by DLR in cooperation with the Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research (AWI) as part of a winter mission at the German Neumayer Station III in Antarctica. Numerous other international partners are working together as part of a research consortium under the leadership of DLR with the aim of ensuring that the Antarctic greenhouse functions properly. These include Wageningen University and Research (Netherlands), Airbus Defense and Space (Germany), LIQUIFER Systems Group (Austria), National Research Council (Italy), University of Guelph (Canada), Enginsoft (Italy), Thales Alenia Space Italia (Italy), AeroCosmo (Italy), Heliospectra (Sweden), Limerick Institute of Technology (Ireland), Telespazio (Italy) and the University of Florida (USA). The project is funded by the European Research Framework Program Horizon 2020 under project number 636501.