Astronauts train for years to learn to perform their duties properly. They learn how to fly a shuttle, walk in space and perform feats of physics unknowable to the average person. They also learn how to use a toilet in zero gravity. Recently, they shared their space tips with the terrestrial-bound world. reports on the different toilet-training techniques used by astronauts in space.

Before astronauts are shipped into the upper atmosphere, they can practice on a specially designed toilet at the Johnson Space Center in Houston. NASA allows astronauts to use a positional training device for practice and a functional trainer for more in-depth sessions. (The functional trainer flushes.) The opening of the positional trainer is only 4 inches wide, requiring some maneuvering. If astronauts are unsure about their positioning on the seat, they can consult a camera that is under the rim. This is to be sure that solid waste will fall through the opening.

Scott Weinstein is a crew habitability trainer at NASA. He recently explained the importance of proper alignment in a NASA broadcast. According to Weinstein, "If they're [astronauts] not confident that they have good alignment … [they] can sit down on the seat, flip on the camera, and check to see if they've got it.” After astronauts master the positional trainer, they move on to the functional one. This functional trainer is equipped with air vents that eliminate both solid and liquid waste.

On the space shuttle, urine is handled differently from solid waste. Men and women have different funnels to choose from for their urine disposal. Women can choose from three funnels, two with oval-shaped tops and one with a circle-shaped top. Men’s funnels only come in one shape with a circular top. Men’s funnels, unlike women’s, do not have vents to air waste. As Weinstein informed, this is to avoid men from “docking” to the funnel.  There are different kinds of space toilets — it just depends on what country the space flyer calls home. The toilet on the space shuttle Atlantis is different from a system used on Russia's Soyuz spacecraft and China's Shenzhou crew vehicles. 

On a recent NASA broadcast, various astronauts shared their toilet tips. Piers Sellers presses his hands palm up against the roof over the toilet to steady himself. Michael Massimino imagines he’s gripping an imaginary motorcycle, sort of like Peter Fonda in "Easy Rider." Steve Bowen, who uses the low roof over the toilet for support, says the toilet’s thigh restraints are helpful as handles for getting in and out of the toilet.  

There won’t be too many more astronauts who will have to deal with the shuttle potty. The shuttle Atlantis is currently on its final mission in space — and only two more missions remain for the entire fleet.