It's a little-known fact that when NASA astronauts venture outside the shuttle, they wear diapers under their spacesuits. An even lesser-known fact is that it's the duty of 47-year-old George Aldrich to sniff them. "Before they're used," he quickly adds.
Aldrich has probably the most unusual and least-known job in the U.S. space program. Each month, he and a small group of volunteers stick their noses into just about everything that goes into orbit - from circuit boards and spacesuits to makeup and toys.
It's an assignment that even some astronauts are unaware of. "News to me," says Tom Jones, veteran of four shuttle missions.
The reason for the tests is simple: Just as the ordinary contents of a car left in the sun can suddenly exude extraordinary odors, so, too, can objects trapped inside the heated confines of a spacecraft start to "offgas." Or in layman's terms: stink.
That could mean trouble for astronauts. "They just can't roll down the window," notes Aldrich, a technician at NASA's White Sands Testing Facility in Las Cruces, N.M.
In 1976, two Soviet cosmonauts were forced to make an emergency landing when an acrid odor overwhelmed the Salyut 5 space station. The source of the smell was never identified.
While NASA has never scrubbed a mission over stench, it's not to say that astronauts are always breathing easy in orbit.
In February, several astronauts on the International Space Station were forced to flee to the Russian crew quarters when something on the U.S. side began to stink. The smell - later traced to an airlock - was "like the odor you get when you crank up your heating system for the first time in the fall," a NASA official reported.
Still, it shut down that side of the station for more than 13 hours and forced at least one American to bunk with Russians astronauts for the night.
A stench also nearly soured the historic first rendezvous of U.S. and Soviet spacecraft in 1975. "We're going on oxygen masks," one American crewmember told Mission Control moments after astronaut Donald "Deke" Slayton opened the airlock and sniffed something foul. "And we're going to close the hatch."
The smell - "like burnt glue" - dissipated, much to the relief of the two crews. To cut down on such malodorous mishaps, Aldrich and his colleagues in the Molecular Desorption and Analysis Laboratory at White Sands first do a toxicity test on items slated to fly in the shuttle or space station. They heat the samples to 120 degrees for 72 hours and then run them through a gas chromatograph mass spectrometer, an instrument that can identify potentially poisonous molecules emanating from the sample. (In his job, Aldrich also runs the tests for the U.S. Navy, whose ships and submarines can be susceptible to offgassing.)
Then an odor panel is convened to give cargo a good whiff. Aldrich is widely considered the panel's master sniffer. Since he first joined NASA in 1974 right out of high school, Aldrich by his own count has participated in 760 "smell missions," as he likes to call the tests. It's an agency record unlikely to be broken anytime soon. His nearest competitors - still in the 600s - recently retired. "They're not going to catch me," he says.
Before the odor tests, which occur six to eight times a month, a nurse inspects each volunteer's nose and throat for signs of colds, allergies or other irritations, all of which are grounds for disqualification. Aldrich says he has had to sit out only twice in 28 years.
The test sample is placed in a chamber and heated. Then a technician draws air from the chamber into a syringe and puffs it into plastic masks worn by volunteers, who rate the odor on a four-point scale, ranging from undetectable to offensive.
Many of the items are routine - epoxies, circuit boards and the like. But Aldrich has also sniffed Nerf footballs, Magic Markers, guitars and a Barney the dinosaur doll.
Over the years, only a few items have been rejected. He and his colleagues still talk about an Apollo-era ink that was so noxious it blistered testers' throats. Sally Ride, the first female American astronaut, saw some of her mascara flunk.
A set of Velcro straps that were hurried into space recently without an odor test would have likely failed. When astronauts in orbit opened the bag containing the straps, the smell almost caused them to launch their lunch. "It was offensive," says Aldrich, who tested them afterward and found they smelled like onions.
To ensure Aldrich's schnoz is up to snuff, three times a year NASA certifies and calibrates it.
The test involves 10 small bottles, seven of which contain odors and three of which do not. Aldrich and his fellow testers must determine not only whether they are scented but what the scent is.
Aldrich says he has never failed, although not all volunteers have been so lucky.
Of course, no matter how sharp their noses, Aldrich and his colleagues can't control every odor aboard the shuttle, which astronauts describe as normally having an "operating-room kind of smell."
"You open up a can of tuna and that would flavor the air for days," recalls Jones, the astronaut. "I've been on crews where people said, 'There will be no canned fish on this mission.'"
As one might expect, Aldrich's unusual skills have attracted attention. He has picked up a few nicknames - the NASA Nose, Nasalnaut and Nostrildamus are some of his favorites. In Spain, thanks to an article in a magazine there, he's known as El Husmeador Jefe.
Co-workers and family members routinely wave him over for his professional opinion when something doesn't smell right. Aldrich has a sense of humor about all this. The greaseboard in his office says: "Astronauts have the right stuff. The master sniffer gets the ripe stuff." His business cards - which are not NASA standard issue but his own doing - show a picture of the space shuttle and a skunk.
He has appeared on game shows, and each March, he serves as head judge of the Odor-Eaters Rotten Sneaker Contest in Vermont.
This, he says, is where his olfactory abilities really get put to the test. Last year, he crowned an 11-year-old New Mexico girl whose winning secret was to wear the same pair of socks for three straight months. Aldrich says his nose told him he probably had the champion long before he stepped up to the judging table.
His nose was right. After reluctantly taking a whiff of the girl's official entry, he "staggered a little," then turned and gasped, "I think I'm going to need some oxygen."
Aldrich is working on a book about his years as a NASA nasalnaut. The working title is Does This Smell Funny to You? While the book will mostly focus on the sillier side of his unusual career, Aldrich says, he also wants readers to take away a more serious message.
"Astronauts are heroes," he says. And if his nose has helped keep them out of harm's way, well, "it kind of makes you proud."