Question

What do trees and other plants look like if grown in a weightless environment?

Plants seem to adapt remarkably well to the space environment. While roots may grow "up" in space and shoots may grow "down" into the soil or growth medium, plants eventually adapt to varying degrees, depending on the species. Without gravity as an orientation cue, plant shoots rely on phototropism (growth toward the light) to orient themselves in the right direction. Interestingly enough, roots don't seem to mind growing in open air. In fact, as long as the humidity is near 100%, roots tend to grow better in air than they do in water or soil. Gardeners and researchers who practice "aeroponics" have known this for several decades, and their methods are currently being investigated for future use in spacecraft life support systems.

For information on the first commercial plant growth experiment on the International Space Station, see http://www.msfc.nasa.gov/NEWSROOM/news/releases/2001/01-169.html
February 22, 2002