Recycling Water in Space
Water - it’s essential for life. When future space explorers venture beyond low Earth orbit, their only water supply will be on board their spacecraft. During the final space shuttle flight, NASA scientists plan to have astronauts test in microgravity a new method for recycling “used” water.
The idea is to make a fortified drink that provides hydration and nutrients from all sources available aboard a spacecraft, such as wastewater and even urine. The method set for testing uses a process known as forward osmosis.
“Forward osmosis is the natural diffusion of water through a semi-permeable membrane,” explains Michael Flynn, research scientist at NASA’s Ames Research Center. “The membrane acts as a barrier that allows small molecules, such as water, to pass through while blocking larger molecules like salts, sugars, starches, proteins, viruses, bacteria and parasites.”
The forward osmosis method already is used for earthbound applications, allowing water of unknown purity to be changed into drinkable water in six to eight hours using a bag containing two chambers separated by a membrane. The commercial technology aids in diverse settings, from outdoor sports like hiking, to the military, to natural disasters where water purification is essential for survival.