You've probably heard of the ceramic tiles on the Space Shuttle and how they had to inspect each one. And the story about the Soviets using a pencil instead of the US "space pen".

Somewhere I read about an early space capsule that had ablative shielding made of hardwood, oak or something several inches thick. "Carbon fiber composite", right? The way I remember it, it was said to work well because the wood was dense and didn't just burn up; instead it slowly carbonized. If you've ever made a fire with a large log, it makes sense. It has to get really hot to catch, and then it lasts a long time.

But I remember it as being attributed to the USSR, and when I search the internet now, I get hits saying it was a story about the Chinese space program that might be apocryphal.