By Dirk Asendorpf

Paul Zabel from the German Aerospace Center operates a greenhouse in the Antarctic, where tomatoes, lettuce and cucumbers flourish. For future space missions, plant cultivation is to be tested under difficult conditions.

"Zabel. Hello. "- A call in Antarctica. Just started there the polar day. 

"We have 24 hours of sunshine when we have no clouds. Today it is very nice. We have the second right summer week. It's only 

about minus 13 degrees. " In recent months, Paul Zabel had to cope with significantly worse weather conditions. For one polar winter, he was responsible for the research greenhouse of the German Aerospace Center. This is located 300 meters from the German Neumeyer Station in a container. 

"We had the lowest temperature with minus 43.4 degrees in August. There were a few days where there were stronger storms, and I did not go because that was just too dangerous. "

He has a satellite connection at all times in the greenhouse 13,500 kilometers away in the view. A dozen screens fill a wall of the control room. 

"We can not touch the plant itself. But we could say for example: The container is now two degrees warmer, we put this here and then the container would be up to two degrees warmer. We could control the light and, for example, we could also give a different nutrient mix to the plant. We can control everything from here. "

A full greenhouse for the first visitors to Mars

The complete remote control of vegetable cultivation in a hermetically sealed container is the prerequisite for its application to future interplanetary space missions. 

"Scenarios provide that the greenhouse system flies to Mars in advance, unfolds there automatically and already plants are grown automatically. And when the first humans come to Mars, they can almost find a fully grown greenhouse. That's the theory. " 

However, the practice was still a long way away. Almost every day Paul Zabel had to look to the right in the Antarctic greenhouse. 

"For example, we had a broken LED lamp from the plant LEDs relatively early in the year. I could then replace it with a spare part. We had several failures of electrically controlled valves and pumps in our cooling system, which are now being replaced by other models. "

The repairs will be carried out by project manager Daniel Schubert personally in January. Then he also brings the seeds for the next test run, including seeds for ten different types of lettuce that Nasa has already tested on the International Space Station. In the Antarctic container they should germinate and grow as independently as possible. A gardener will not exist in the next polar winter.

The greenhouse should be completely remotely controlled

"We could not find anyone who would like to hibernate again. And then we thought: Could we do a self-sufficient mission? So really just observe and control the greenhouse system only from Bremen, out of our mission control center. And we say to the overwinterers: Only go in an emergency - or to harvest. " 

Paul Zabel flies back in mid-December to Bremen. There he missed a century summer. 

"I also talked regularly with my colleagues and then I was a bit jealous here and there. But I was just a year in the Antarctic. But chirping birds and being able to go out into the forest again, these are things that you just can not do here. And I'm definitely looking forward to that. "