Questin about the smell of space

This months Atlantic Monthly has a very good article (alas, not available without a subscription online) on the Columbia disaster and provides a lot of little details I had not heard of before. At one point the writer is having a conversation with a shuttle commander who describes the smell of the cabin after a spacewalk or such as having the smell of a “torch on metal.” Does anyone have an explanation for this? Singed particles from the shuttle itself?

Not sure about the shuttle, but the Apollo moonwalkers all mentioned a gunpowder-like smell in the LEM after their EVAs. Apparently, it was a chemical reaction between something in the lunar soil and the oxygen in the LEM.

I wonder if the shuttle commander quoted was an actual participant in the EVA or not. It may be that after several hours of breathing pure oxygen during the EVA, perhaps the normal ambient odors of the cabin are simply more intense at first upon going back into the shuttle?

From an old “Star Trek” episode:

SPOCK: Ensign, how close are the Klingons to this sector of space?

CHECKOV: 50 parsecs, sir…close enough to smell them!

SPOCK: Illogical, Ensign – smells do not travel in the vacuum of space.

CHECKOV: I was making a little joke, sir.

SPOCK: VERY little, Ensign.