Tsiolkovsky, Konstantin Eduardovich, (1857-1935) was a Russian physicist who laid many of the theoretical foundations for the science of rocketry. In The Investigation of Outer Space by Means of Reaction Apparatus (1903), he discusses the mathematics of overcoming the earth’s gravitational pull by means of rockets, suggests the use of reaction vehicles for interplanetary flight, and describes how a reaction thrust motor could demonstrate Newton's Third Law to allow men to escape the bounds of Earth. In 1929, Tsiolkovsky presented a design for a multistage rocket, which he called a rocket train. He also proposed the construction of an artificial earth satellite, including manned space platforms to be used as way stations in interplanetary travel. Tsiolkovsky is known for saying: "Earth is the cradle of humanity, but one cannot remain in the cradle forever."