There's a movie called October Sky.
It's about a kid who overcomes the odds and gets out of deadend coal-mining town after he's inspired to make rockets when he sees Sputnik.
His first rocket consists of a cardboard tube taped to a toy plane, filled with the powder of about 30 skyrocket fireworks. He and his friends are about to see if it can go 'a few miles high'.
They light it and step back a few feet, counting "10, 9, 8, (Should we get behind something?) 7, 6," EXPLODE and knocks them all on their ass. I laughed for like half an hour before summoning the energy to watch that scene again.