Many Things Went Wrong, Growing Plants in Spaceby Frank B. Salisbury, Ph.D.
Many Things Went Wrong
Our experiment was carried out from August to November 1995, but many things went wrong. Two thirds of the lights stopped functioning very early in the experiment, and that was a serious thing because plants need light to grow, and when all the lamps in Svet are functioning, there is just enough light for food growth. There were other problems, but the plants did stay alive for 90 days and we got the chemically fixed samples back. Not a single plant formed even one wheat head! Right now, we don't understand this because when we grow the plants under such low light on Earth, they form a head (sometimes almost microscopic) even if they have so little light that they eventually die. Wheat has formed heads in space, however, so the fact that our plants did not flower is perhaps, the most interesting thing we learned in this experiment. We are doing many ground experiments to try to find out why the plants stayed vegetative. It was also important to see the equipment we built in Utah worked just fine! The entire experiment is being repeated as I write this: seeds planted on August 5, 1996, and samples to be brought back in early February 1997.
Growing Plants in Space
Why do we want to grow plants in space? For one thing, because plants are extremely sensitive to gravity. If a young seedling is tipped just a few degrees from the vertical, it will change its direction of growth within a few hours until it is again growing straight up. (Plants will also grow toward a light if it is coming from one side for awhile, but if the light moves overhead as the sun does, then the response to gravity is much stronger -- most plants do grow straight up, at least before they begin to branch.) Even after about 130 years of truly scientific study, we still don't know exactly how plants respond to gravity although we do know a lot about what is going on. Maybe if we see how they grow when there is no directional gravitational force, we can learn something about gravitropism (how plants respond to gravity). Additionally, the day might come when astronauts/cosmonauts grow plants in space to purify the air (take out carbon dioxide and release oxygen) and provide food. Clearly, if we are ever to reach that goal, we must learn how to grow healthy plants in microgravity.