Life in space isn't easy, even if you are green
In order for terrestrial life to expand beyond the confines of our earthbound existence to bodies such as the moon or Mars it will have to tackle a barrage of stresses, some that it has encountered and adapted to over millions of years of evolution, but some that it will meet for the very first time. Whether reliable, sustainable biology-based (bio-regenerative) life support systems can be developed for long-duration spaceflight and extraterrestrial colonies has therefore become an important area of research. These systems would almost certainly centre on plants and microbes and so questions of how such organisms respond to reduced gravity and radiation become critical. Current research, using approaches ranging from gene expression and protein profiling to detailed growth analyses, suggests spaceflight triggers complex stress responses in these organisms, but that biology has a remarkable ability to cope with the life of a space alien.