Storage is hard to come by aboard the International Space Station. Even if a rocket had room to ferry thousands of pounds of water and oxygen to supply a six-month mission, you’d struggle to find anywhere to stash it. So engineers have devised creative ways to squeeze essentials from astronauts’ sweat, urine, and breath. But we’re not at total recovery yet. Right now, the ISS recycles 90 percent of its water—or more than 1,000 gallons annually—and 40 percent of the oxygen astronauts breathe. The rest comes up on resupply missions. This diagram shows how NASA gets so close to a self-sustaining space home.
Continue reading How the ISS recycles its air and water