The Smell of Space
According to NASA scientists, space smells a lot like my uncle's workshop. One can detect hints of fried steak, hot metal, and the welding of a motorbike. They have hired Steven Pearce, a chemist and managing director of fragrance manufacturing company Omega Ingredients, to recreate the smell in a laboratory. NASA will use his research to help train potential astronauts. Steven said, "I did some work for an art exhibition in July, which was based entirely on smell, and one of the things I created was the smell of the inside of the Mir space station. NASA heard about it and contacted me to see if I could help them recreate the smell of space to help their astronauts."
Bingo.
Could you imagine if humans lost the ability to smell smoke? A hell of a lot more of us(no pun intended) would burn to death in fires were it not for our ability to do so.
NASA simply realizes the importance of smell in many aspects, from diagnosis of a problem to the signaling of humans that a problem exists in the first place.
Astronaut A reenters the shuttle. Astronaut B smells something OTHER then the smell of space on the suit of astronaut A as he reenters. At this point it can be assumed it is time to take a closer look at the situation.
The point is that knowing what space smells like establishes a scent baseline allowing for better analysis of the situation.