What's The Deal With The Diapers?

The sad story of astronaut turned accused stalker Lisa Nowak raises so many questions. Why didn't NASA testing screen out what appears to be a case of obsessive attraction? What is it about William Oefelein that evidently makes him catnip to the female shuttle folk? And, perhaps most indelicately, what's up with the diaper?

To avoid time-wasting rest stops, Nowak drove the 900 miles from Houston to Orlando wearing a diaper, according to authorities. The detail caught the eye of many curious readers, but in the aerospace community it's not a new concept.

In Neil Armstrong's day, astronauts wore urine and fecal containment systems under spandex trunks. The reason, says camp director Teresa Sindelar of the Kansas Cosmosphere and Space Center, was purely practical: "You can't just drop your space pants and go." But by the early 1980s, flight crews were routinely spacewalking for seven or more hours at a stretch--without bathroom breaks. To suit their needs, NASA invented space diapers (known as Disposable Absorption Containment Trunks, or DACTs). DACTs debuted during the first space-shuttle Challenger mission in 1983.

So how do space diapers work? A lot like regular diapers, except that they absorb more liquid and slide on like bike shorts. When an astronaut "uses the restroom," sodium polyacrylate powder, which is woven into the fabric, quickly soaks up the fluid, and the diaper pulls it away from the skin. All told, the chemical can absorb up to 1,000 times its weight in water, meaning astronauts need to change diapers only every eight to 10 hours. Provided, of course, that they "go No. 1 in the diaper and save the other stuff for when they are onboard"--standard operating procedure, says Sindelar.

Astronauts are generally issued three diapers--one for launch, one for landing and one for any spacewalking, says Sindelar. Given the tight controls, it's unlikely, though not impossible, Nowak wore NASA-grade garments on her drive. "I doubt NASA would allow her to have her own stash," says Sindelar. "I would guess she went and bought a box of Depends."