Today, NASA astronaut Scotty Kelly is embarking on historic mission: He plans to spent the next 365 days on the International Space Station.
That’s longer than anyone has ever spent on the ISS, as well as the longest stretch that any American has ever spent in space, period.
In honour of the occasion, NASA tweeted out the following “fun” fact:
The International Space Station can recycle about 93% of the liquids it receives — in this case, urine and sweat. Although it sounds gross, the liquid — which takes 8 days to recycle — is actually even more pure than the water that most people drink at home.
For reference, 730 litres is equivalent to nearly 200 gallons.
Learn more about the purification process in this video:
(Also, in case you’re curious, astronaut poop gets collected into an unmanned space ship that will get burned up when it returns to earth).