A few days ago, we were telling you about the espresso machine 3D printed onboard the International Space Station. Now, it’s time to go full circle and look at how the coffee… gets out of the body. Here’s how astronauts use the toilet (yes, in case you’re wondering, this is suitable for viewing at work):

Above, we see Samantha Cristoforetti, an Italian astronaut, explaining how urinating happens in outer space – which in zero gravity, is quite a challenge. Basically, they go into the rubber hose that uses suction to collect urine so that it doesn’t float all around. After that, everything is transported to the urine processing assembly (UPA) and it is recycled into drinkable water.

Recycling it is critical to keeping a clean environment for astronauts, and when onboard water supplies run low, treated urine can become a source of essential drinking water.

But if we go even deeper into the urine processing (heh), we learn that it uses a low pressure vacuum distillation process that uses a centrifuge to compensate for the lack of gravity and thus aid in separating liquids and gasses. It can handle a load of 9 kg/day, corresponding to the needs of a 6-person crew. About 70% of the urine’s water content can be recovered as drinking water. Of course, water is tested by the onboard sensors and unacceptable water is sent back for refiltering.

In outer space, pretty much everything is complicated – so enjoy and appreciate your comfy home toilet.