July 7, 2011 at 12:52 PM ET
During the final days of shuttle Atlantis' final flight, an astronaut will inject a urine-like fluid into a special bag designed to convert the fluid into a drinkable, sugary solution. If it works, future astronauts may use it to make their own pee a safe and satisfying liquid refreshment.
Astronauts on the International Space Station already drink recycled urine but the glitch-y system takes energy from the orbital lab's limited supply. The new system doesn't require electricity; rather it relies on a process called "forward osmosis."
NASA describes forward osmosis as "the natural diffusion of water through a semi-permeable membrane from a solution of a lower concentration to a solution with a higher concentration. The semi-permeable 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 semi-permeable membrane (a bag) is filled with a sugary solution that is nested within an outer bag. The dirty fluid — including pee, sweat and dishwater — is injected into the outer bag. As it makes it way to the inner bag, the contaminants are left behind. The result, if all goes well, is a quaffable liquid.
One of the four astronauts will test the textbook-size recycler toward the end of Atlantis' 12-day mission, scheduled for liftoff on Friday. Fortunately, the test will be with a pee-like solution, not the actual bodily fluid.
The system was demonstrated to reporters at the Kennedy Space Center this week. Wired's Dave Mosher, who was on scene, has the details.
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