We just learned about how Specific Impulse measures how a rocket works.
Some of the first rockets that were made came from China over a thousand years ago, after the invention of gunpowder.
These were known as Fire Arrows.
At first people just had the idea to tie an explosive ball of gunpowder to the arrow that would blow up after the arrow was shot with a bow.
Later on someone figured out how to use the gunpowder as a solid propellant for the rocket in a wooden tube as the propellant tank, and use the burning of the gunpowder to thrust the arrow up higher and farther.
(from: wikipedia - fire arrow)
Kid Facts - Blast from the past: Burr
