The most common question for astronauts aboard the International Space Station (ISS) isn't about the exciting experiments they conduct up there, according to Commander Chris Cassidy, nor the wonder they experience as they gaze down upon the Earth, but how they take a poop. Imagine being able to tell somebody what it feels like to leave the Earth's atmosphere, and even the safety of the ISS in order to perform a spacewalk, and they ask you "how do you take a poo though?"
Nevertheless, there's an interesting history and indeed grim history to pooping and peeing in space that's worth talking about. In a new video, Commander Chris Cassidy has given a tour of the ISS toilet and explained in detail how to use it, but first a little history.
During the early days of the Apollo missions, NASA didn't think about peeing and pooping too much. When the first American man went into space, they made no plans at all for if he needed the bathroom. The trip was only supposed to be short, so they figured he'd be able to hold it. However, due to delays prior to launch, he ended up having to wait on the launchpad for hours and ended up having to pee himself.
For longer space trips, NASA had to figure out a better system. Before Apollo 12, the main way astronauts went to the toilet was into collection bags. For peeing, this involved inserting your penis into a tube with a rubber, condom-like end. This had its own problems in that the sheaths would often fly off in space, largely due to a sizing problem.
For pooping, astronauts would take a fecal bag and use a "finger cot" to position it over the anus.

For excursions outside of the spacecraft, astronauts would have to use the fecal containment system (FCS), which is a "pair of underpants of absorbent material worn under the liquid cooling garment." This is a fancy way of saying that when man first walked on the Moon he was wearing a diaper.
Thankfully, the toilet situation has moved on somewhat since the early days – at least inside spacecraft – not least because they had to adapt in order to accommodate female astronauts, for whom a sheath would be somewhat impractical. Now they have an advanced bathroom facility on the ISS. The latest space toilet technology costs a whopping $23 million, in fact.
Commander Chris Cassidy explains in this new video how the systems work. You basically get a vacuum hose for your pee and, well, we'll let you see for yourself but it involves a big stick for poking a poop bag.
Oh the glamour of space flight.