An astronaut's guide to using the bathroom in space

One of the most popular questions asked of astronauts is how they use the bathroom in space. That prompted NASA astronaut Chris Cassidy—who just retuned to Earth last week after six months as commander of the International Space Station—to create a video guide to using the, er, Waste and Hygiene Compartment (WHC) as it's officially called. There's even a checklist on proper use. The process involves a lot of suction and, unfortunately, isn't well-designed for women. (Fortunately, a newly designed toilet was delivered to the ISS last month.) From

Switching on the valve creates airflow which sucks through the funnel on the hose. Astronauts pee directly into the hose, which suctions the pee straight to the UPA. To go #2, however, they have to use something that looks a little more like a toilet. 

The space station's toilet (which also has a clever acronym, though Cassidy couldn't remember what it stands for besides "container for something") is a seat on top of a bucket that holds about 30 "deposits," Cassidy said. Opening the lid reveals a hole only about five to six inches in diameter that is wrapped in a plastic liner. To use it, astronauts sit around the hole just as we would on Earth, poop, wipe themselves and then put the wipe inside the hole. The same suction system that uses airflow to keep urine from flying out of the funnel also works to keep all of the "deposits" inside the toilet. 

image: NASA