I took this stuff I got out of your [O-ring] seal and I put it in ice water, and I discovered that when you put some pressure on it for a while and then undo it it doesn't stretch back. It stays the same dimension. In other words, for a few seconds at least, and more seconds than that, there is no resilience in this particular material when it is at a temperature of 32 degrees. I believe that has some significance for our problem.

statement at hearing by Rogers Commission, 11 February 1986, Report of the PRESIDENTIAL COMMISSION on the Space Shuttle Challenger Accident, volume 4, p. 680; also quoted in Genius: The Life and Science of Richard Feynman (1992) by James Gleick, p. 423