the space smell, a sense of deja vu

it'll be four years -- on STS-102 in 2001.
One of the things that struck me when I went on the Space Station, especially the Russian segment, was, it was a sense of deja vu -- it was like being on Mir again because the Russian segment is very much like Mir. It even smelt like Mir.
The air treatment systems are the same and they leave that slight residual odor. Sergei Krikalev, one of the senior Russian cosmonauts, says it's "the space smell." You get used to it. But I was really struck by this deja vu sense I had when I went into the Russian segment of the Space Station.

NASA - Preflight Interview: Andy Thomas
http://www.nasa.gov/vision/space/preparingtravel/rtf_interview_thomas.html