In the 1950s, green things burst from book covers and into the lab. NASA and the U.S. Air Force started growing algae to see if it could help with life support (turns out, it tasted bad, was full of indigestible cell walls, and had too much protein). Then, Soviet scientists experimented with nearly self-sufficient ecosystems in which humans survived on oxygen, water, and nutrition produced mostly within an enclosed habitat. In the longest run, a 180-day trial inside a facility called BIOS-3, an earthbound crew got 80 percent of its food from its own wheat and vegetables. Finally, in 1982, plants in space became a reality when Soviet cosmonauts grew Arabidopsis thaliana, a flowering species related to cabbage and mustard, to maturity aboard their Salyut 7 space station. The yield was too small to be a source of food.