When humankind sends the first astronauts to Mars for their six-month journey aboard the Orion spacecraft, what will they eat? Tor Henning Iversen is not a food service professional, but he's interested in helping find the answers nonetheless. As a biology professor at the Norwegian University of Science and Technology's Plant Biocentre, Iversen is spearheading Norwegian efforts to investigate how plants grow in space - with the eventual goal of enabling astronauts on long journeys to grow their own food.
"You can't compare what we do on the ground with what we do in space," Iversen said. Plants use gravity to help orient their roots and to push against as they grow - which means that the zero-gravity conditions of a six-month space flight might be challenging indeed. The only way to find out how plants might react is by experimenting with growing them in space - a job that is uniquely suited to the International Space Station.
Growing a plant in space is much more difficult than it might seem. First, researchers had to develop a special growth chamber, called the European Modular Cultivation System (EMCS), which is a climate-controlled incubator that is divided in two, with rotors that enable each half to spin at a sufficient speed to generate its own artificial gravity if needed to provide an experimental control for scientific comparisons. The EMCS is remotely controlled from Earth by scientists at the Plant Biocentre, where the European Space Agency has authorized the creation of the Norwegian User Support and Operation Centre (N-USOC) - just one of 10 USOCs approved by the ESA throughout Europe. Any researcher wishing to use the EMCS must work with the Norwegian centre. Five research projects have already been selected for the first phase of the project, with researchers hailing from the United States, France, Italy and Norway.
Other, equally challenging problems have included designing a pot to nurture seeds being grown in the various experiments. The resulting design looks like no flowerpot you have ever seen; instead it is a rectangular piece of metal the size of a paperback book laced with electronics. The pot has more than 100 components and is being manufactured by CMR Prototech in Bergen.
One of the most difficult aspects of creating the pot was controlling the amount of water delivered to the plant. "Water consumption is critical in plant growth, but it is also very heavy," Iversen said. Because of weight limitations, one of Iversen's experiments, which involves growing a plant from seed to maturity and seed production, is limited to one litre of water - which has to last through the three months that the plant will take to complete its life cycle.
Then there was the problem of anchoring seeds in the weightless environment - what kind of film or membrane would both be able to trap the seed as it put out its first roots, and yet be porous enough to permit the seed to grow without the aid of gravity? In short, every aspect of plant growth has to be considered, tested and engineered - or the astronauts won't eat. "We know how to grow plants," Iversen said. "But in zero-gravity, we need to know if there are going to be any key problems that will show up."
|This plant cultivation chamber (PCC) is used to conduct research on plant growth in the International Space Station. The pot has more than 100 parts and is made by CMR Prototech in Bergen.
© Bjørn Pedersen/Norwegian User Support and Operation Centre