Space Shuttle Challenger O-ring

1986 Challenger explosion. Tom's reflexive prediction: "I bet it failed at a weld." Correction: O-ring seal — not a weld but still a joint. Used to anchor the "failures happen at joints" thesis.

The space shuttle — when the space shuttle blew up in 1986, one of my students came rushing in: did you hear the news, the space shuttle just blew up. This was before the internet, so things didn't pass quite as quick. My first comment was, I bet it failed at a joint. Actually I said, I bet it failed at a weld. I was wrong, it didn't fail at a weld, but it did fail at a joint — it was an O-ring seal. When something fails, it has a very high likelihood of failing at a joint.