May 22, 2010

How To Use A Space Toilet

NASA trainees may have to go through some rather tough training to become full-fledged astronauts, but one of those tasks everyday people take for granted may be trickier than thought.

Learning to use the bathroom in outer space is tricky business. That's why NASA has a specially designed training room at the Johnson Space Center in Houston where astronauts can carefully sharpen their skills before being launched into orbit.

Astronaut Michael Massimino recently gave a behind-the-scenes look at how the system works while the six-man crew of the current NASA shuttle mission is in orbit.

"You know what I think of? I think of Peter Fonda in 'Easy Rider' riding a chopper," Massimino said of his preferred potty position, holding his arms up to grip the handlebars of the imaginary chopper. "That's the right position for me."

Different spaceships have different type of toilets. A Russian design similar to the shuttle is used on the International Space Station, where Atlantis is currently docked. Other systems are used on Russian Soyuz spacecraft and China's space vehicles.

NASA astronauts have two shuttle toilet stations in the training room. A positional trainer is made for practice and a functional trainer that actually flushes. The positional trainer is not a working toilet, but is identical to the space toilet on the shuttle. The seat opening is just 4 inches wide, compared to standard earthen toilet seat openings of 12 or 18 inches.

A small camera is located inside the toilet, just under the rim of the opening. The camera feed runs to a monitor just a few feet in front of the seat. Astronauts can use the monitor to make sure their bodies are positioned correctly so the waste falls through the seat's small opening.

"Alignment is important," said Scott Weinstein, a crew habitability trainer at NASA. He explained the intricate workings of the contraption during a recent NASA TV broadcast. "If they're not confident that they have good alignment" they can sit down, flip on the camera, and check to see if they are on track.

When astronauts have mastered the proper alignment, they can move to the functional trainer. The functional toilet at the training station is the same thing used on shuttle missions, right down to the same airflow vents.

On the shuttle, urine is handled differently than solid waste, so it doesn't go through the 4-inch opening. Instead, a long hose with suction power attaches beside the seat, and each astronaut attaches his or her own funnel for urination to their hose.

Funnels are different for men and women. Women need to place the top of their funnels directly against their bodies, so the sides of the funnels need to be vented so that air can flow in when suction is turned on, explained Weinstein. There are three different funnel styles for women to choose from.

Funnels for men are much simpler. They only come in one style and they do not have venting. "For men, we do not want them ... docking to the funnel," said Weinstein, so male funnels do not need venting.

Paper waste also has a separate system. A suction hose on the side of the toilet can be fitted with a larger cup and lined with a plastic bag.

Straps on the foot rest can help to hold an astronaut in place, and two thigh restraints on the sides of the toilet can be used to help a person stay down on the toilet. But not everyone uses them.

Before the recent Atlantis mission, astronauts gathered in the room and compared their techniques for staying in position when they are weightless.

Astronaut Steve Bowen said the thigh restraints are helpful to use as handles for getting in and out of the toilet, but he uses the low roof over the toilet to stay in position.

The mission, which launched last week, is expected to be the final flight of Atlantis as NASA prepares to retire it shuttle fleet this year. Only two more shuttle missions remain for NASA.


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