How Space Station Alpha's Toilet Works

by Phillip Chien, Popular Science

Inevitably, everyone wants to know about the toilet. The toilet provides more than just relief; its a partial recycling system. Urine is distilled to create purified water. The recovered water is pure enough to drink, but few astronauts are willing to do so. So the recovered water is used in the Electron unit.

The Electron passes electricity through water, separating it into hydrogen and oxygen. The hydrogen is vented as a waste product, and the oxygen is added to the stations atmosphere. Solid waste goes into bags that are stored in airtight containers, which are eventually loaded onto Progress freighters that burn up in the Earths atmosphere.

Each shuttle mission to the space station leaves several 12-gallon bags of water, a waste product generated by the shuttles fuel cells. That water can be used for oxygen generation, cleaning, and drinking. The water from the reclaimed urine is stored in case a need for it arises in the future.

For a complete list of stories published by SPACE.com about Expedition One's visit to the International Space Station, see this collection of mission files.