If you're going on a long space trip, you'll soon realize that you can't carry all the fresh water you'll need with you. The cost of getting all that water into space would destroy your budget before you ever built a single photon torpedo launcher. The answer, of course, is recycling. Those childhood dreams of traveling to space probably didn't include drinking your own sweat and pee.
If you'd like to enjoy a cool pint of fresh water in space, the "shipped-from-Earth" variety will cost you $15,000. That's why the International Space Station captures every bit of evaporated water possible, collects it and purifies it for use as drinking water. While astronauts were apparently fine with drinking each other's sweat, exhaled water vapor and shower water, NASA hadn't crossed the urine barrier yet. But that's about to change.
Last week, Space Shuttle Endeavor carried aloft a Michigan Technological University designed Water Recovery System. Here's how it turns pee into a refreshing drink:
1). Urine is distilled, removing a bunch of the "bad stuff" you wouldn't want to drink.
2). It's combined with the other waste water (the sweat and shower water).
3). Solids are filtered out. You don't want someone's hair in your morning drink.
4). The water passes through a bunch of multi-filtration beds made of materials that remove contaminants either by absorbing them or negating them via ion exchange.
5). At this point, the water holds some non-organics and solvents. A reactor breaks those impurities down into carbon dioxide, water and ions.
6). Leaving behind the CO2 and the ions gives you water that's as pure as a mountain stream. Probably purer. Image by: NASA.