eu 1500. Rarissimo. In 1929 he published his theory of multistage rockets, based on his knowledge of propulsion dynamics.He read Jules Verne's stories of space travel and began to write science fiction stories himself. He introduced elements of science and technology into his stories, such as the problem of controlling a rocket as it moved between gravitational fields. Gradually Tsiolkovsky moved from writing science fiction to writing theoretical papers on topics such as gyroscopes, escape velocities, the principle of action and reaction, and the use of liquid propellant rockets. ( )