Before the Challenger accident, back in the mid 80's the USAF flew several classified Orbiter missions. At the time, I remember reading an Aviation Week column, where the writer speculated that one of the flights was a training mission with the goal of developing an on orbit refueling capability for reconnaissance satellites. That sounds like a great idea at first, but since most satellites use fuels like Hydrazine and Nitrogen Tetroxide for RCS, wouldn't that be incredibly dangerous?
I'm just thinking, if an EVA suit was contaminated, they couldn't bring the guy back into the cabin without poisoning everyone.