When I first heard this story, I didn't believe it.

How could an iron manhole cover be the fastest human-made object ever launched?

I honestly pictured something akin to the exploding manhole covers that terrify NYC residents:

It wasn't like that. This manhole cover was shot into space with a nuclear bomb.

Robert Brownlee, an astrophysicist who designed the nuclear test in question, told Tech Insider the unbelievable story.

He refutes his critics and asserts that yes, it likely was the fastest object that mankind ever launched. Here's how Brownlee says history was made.