Ooga the burning-hot-spirit-tamer, who set his friend on fire by accident, while trying to prank him, by throwing flintstones at him.

One of the thrown flintstones hit another and created a spark that set a pile of wood on fire, which served as Ooga's friend's bed.

Amazed by this spectacle, Ooga began throwing more flintstones and smashing them together and setting more things on fire inside their cave and thus - learned how to tame a flame.

At least, that's how I imagine it went.

And now, because of this, we are able to send things into space.