unreasonable.org

ISS Science Officer Don Pettit writes about the smell of space:

It seems about as improbable as listening to sounds in space, yet space has a definite smell...I had the pleasure of operating the airlock for two of my crewmates while they went on several space walks. Each time, when I repressed the airlock, opened the hatch and welcomed two tired workers inside, a peculiar odor tickled my olfactory senses. At first I couldn't quite place it. It must have come from the air ducts that re-pressed the compartment. Then I noticed that this smell was on their suit, helmet, gloves, and tools.