Astronauts may not expose their nostrils to the vacuum of space, but folks who come back from space walks report that they've brought a very distinctive odor back with them. And the space stations have their own special (and not necessarily pleasant) scents, including perfume of the Mir Space Station, which is currently being bottled.
Steve Pearce, a chemist at Omega Ingredients and Maverick Innovations, was approached by a curator at the Reg Vardy Gallery who wanted to create an exhibit of unusual odors. Pearce has ended up working out the smells of Cleopatra, the last meal of condemned murderer Jesse Tefaro, and the Mir Space Station. Pearce explained to Discovery Space that he's looked to astronaut's descriptions of what they term the "smell of space:"
When astronauts come in from a spacewalk and remove their helmets, they've reported smells of "seared steak," "hot metal" and "arc welding on their motorbike."
These are all consistent descriptions, not flukes. That led us to conclude that the sensation is caused by some high-energy vibrations in particles brought back inside which mix with the air.
Mir had its own special odor, however. Apparently, when the designers conceived of the station's air and water recycling systems, they didn't account for the fact that cosmonauts would likely bring vodka with them. Thanks to the changes in their breath and perspiration, acetone, acetaldehyde, and other none-too-pleasant smelling materials found their way into the air. As Pearce has been developing the smell of being cooped up on Mir for too long, his inspirations have been smelly feet, body odor, nail polish remover, and gasoline. NASA is hoping to use these scents as part of their training program, so that astronauts headed on space missions have a stronger sense of what their noses are in for. It's probably just as well that one's sense of smell dulls in space.
Image from NASA.