Who's your favourite screw-up in history?
(I'm leaving this category wide open so you can take it positively or negatively: someone who screwed up in a way that actually worked out wonderfully in the end, someone who screwed up massively in one field but still did good elsewhere, or someone who just failed so spectacularly that the extent of their incompetence is almost beyond comprehension. Your call! 🙃)
@MLClark Since it's "my" favorite ...
Vanguard TV-3, December 6, 1957. It failed seconds after liftoff. If it had worked, it would have placed an inert six-pound ball in orbit. Although it wouldn't operate, technically it would have been the first U.S. satellite.
Because of that failure, von Braun got the green light to launch Explorer 1 on January 31, 1958. He became a hero.
If TV-3 had worked, maybe von Braun doesn't launch, and certainly doesn't become a hero.