Konstantin Eduardovich Tsiolkovsky (Константин Эдуардович Циолковский, Konstanty Ciołkowski) (September 5, 1857 new style – September 19, 1935) was a Russian and Soviet rocket scientist and pioneer of cosmonautics who spent most of his life in a log house on the outskirts of the Russian town of Kaluga.
He is also known for his famous saying: "The Earth is the cradle of humanity, but one can not live in a cradle forever!"