Actually, it was merely ice water he dipped the o-ring in. Since the weather was below freezing that day, it was a reasonable test. He squeezed the o-ring in a little C-clamp, dunked it in ice water during a televised meeting, and showed how it wasn't very resilient at those temperatures. The o-rings needed to be very quickly resilient to do their job correctly. I remember hearing at the time about the o-rings failing. But the real issue was, NASA had gotten lazy, and communication was poor. They tried launching at a temperature the o-rings were not rated for, 28 or 29 degrees. Previously to that, the coldest it had been for a launch was 53 degrees. I just checked the story in Feynman's book, "What Do You Care What Other People Think?"brianormond wrote:-Richard Feynman also appeared before the Rogers Commission following the Challenger space shuttle disaster. I heard he took o-ring material used on the solid rocket boosters, dipped it in liquid oxygen or nitrogen for a quick freeze, then broke it apart in front of the panel to demonstrate graphically how frozen or stiffened o-rings doomed the shuttle.
Feynman was indeed a very interesting character. I think one of his greatest contributions was to embody (and write about) a way of thinking, making no excuses, going back to reality, questioning yourself, trying to prove yourself wrong, and being comfortable with doubt instead of always trying to be "right." As he said:
"Science is a way of trying not to fool yourself. The first principle is that you must not fool yourself, and you are the easiest person to fool."
