“Here on board the ISS, we turn yesterday’s coffee into tomorrow’s coffee” is a slogan that sounds a little like a Don Draper-led advertising campaign. Seriously, though, it’s a nifty way in which Expedition 39 commander Koichi Wakata describes in this video (also embedded below) how the astronauts drink purified urine on the station.
The water is perfectly hygienic once it runs through the system, and moreover, it could be a useful trick for future space colonists to remember.
Water is heavy, at about 8.3 pounds per gallon (or roughly 1 kg/liter) at room temperature. And astronauts in space do need to go through a lot of it to prevent dehydration and other illnesses. Throw in demanding activities such as exercising two hours a day or going on a spacewalk, and you can see how quickly people in space go through it.
Everything sent into space has an associated launch cost with it, and space engineers are always looking for ways to shave a few grams here or there. By installing the water purification system (which was completed in 2009 with Wakata on board), NASA said it would be able to reduce the amount sent up to station.
When people speak of space colonies on the Moon or Mars, they often talk about landing them near a large source of water ice and then using that to help support the people working there. As NASA once wrote in a worksheet, “Until an orbiting grocery store is opened, recycling of water and air will be crucial for crew survival.”
Check out Wakata’s explanation of the water recycling system below. For more information on recycling water in Mars colonies, one source to start with could be T. A. Heppenheimer’s “Colonies In Space”, published on the National Space Society website.