So far, Paul Zabel has not been so keen on gardening with gardeners. Nevertheless, his plants grow like crazy – and that in the Antarctic. This is made possible by a special greenhouse near the German polar research station “Neumayer III”.
Every day Zabel stomps thickly packed 400 meters through the snow into the countryside, sowing lettuce, cutting back tomato plants and checking whether his fosterlings are doing well. He can now enjoy the reward of his work: he has just harvested 3.6 kilograms of lettuce, 70 radishes and 18 cucumbers.
“It was very special to have the first fresh salad of the Antarctic in mind,” says Bernhard Gropp of the Alfred Wegener Institute, station manager of “Neumayer III”. “He tasted like we had him freshly harvested in the garden.” There are a total of ten overwinterers on the station.
There have already been experiments with greenhouses at other polar research stations in the Antarctic. During the Antarctic winter, the scientific outposts are cut off from the rest of the world. Flights are only available in exceptional medical conditions. For months, the station crews have to consume their supplies. On “Neumayer III” there was the last food delivery at the end of February. At this point, Zabel was just sowing the first seed.
Gardening in seclusion is a challenge. In the Antarctic greenhouse there were minor system failures after construction. In addition, the strongest storm swept across the station for more than a year. In addition: Zabel must get along with the existing resources, replenishment does not exist. Similarly, astronauts must feel.
The moon and Mars are the ultimate goal of space engineer Zabel and his colleagues at the German Aerospace Center (DLR) in Bremen. The greenhouse, which they developed, is designed to provide astronauts with information when exploring distant planets. And not only that: it should be the green lung of the space stations. “It makes oxygen for the astronauts to breathe and purifies the water,” explains project leader Daniel Schubert.
Schubert looks at the many screens in the Bremen control room. From there, he and his team monitor everything that happens in the greenhouse. Monitors display temperature, humidity, oxygen and carbon dioxide levels. A camera regularly photographs all plants. Lush green salads, yellow-flowering tomato plants, basil, chives, parsley, cucumbers, kohlrabi and small rocket seedlings sprout on eight floors. Only the strawberries are not sown yet.
The joke with the whole thing: The vegetables sprout completely without soil. “Aeroponics” is the name of the procedure. The roots are much larger than plants that grow in soil. Otherwise, however, the plants trapped in plastic mounts look like they are in a well-tended hobby garden – and smell the same way: amazingly natural.
In May, the researchers expect full operation of the container greenhouse. Then around four to five kilograms of fresh vegetables are to be harvested per week. The plants grew faster than under normal conditions, says project manager Schubert. Every five minutes, the roots of the plants are sprayed computer-controlled with a nutrient solution, they get more light and carbon dioxide than usual. Especially important for the project are the closed circuits. Air and water are recycled again and again, as it would have to be in space.