I just wanted to point out, that Teflon wasn't from the space program.
It was from the WWII nuclear weapons development program.  Pipes in the 
system for fractioning and enriching uranium had to be lined with it.

Uranium Hexafloride was the chemical they turned the pitchblend into for
enrichment.  It is massively corrosive.  Even to Stainless steels. Hence
the need for a very inert substaance to line the pipes with.  Teflon has
all its molecular sockets bound up already, so it is very unreactive.

My 2 sense worth.