The first object in history to use rocket propulsion was not invented by a rocket scientist, but by Greek philosopher Archytas around 400 B.C. Archytas amazed the citizens of his community by flying a wooden pigeon suspended by wire that was powered by escaping steam. Centuries later, principles behind rocketry and jet propulsion were discovered, albeit unknowingly, by the invention of a steam engine known as the Hero Engine or the aeolipile in 10 A.D. in Alexandria.