Konstantin Tsiolkovsky, Russian scientist and engineer (b. 1857)
Konstantin Eduardovich Tsiolkovsky (Russian: Константи́н Эдуа́рдович Циолко́вский; 17 September [O.S. 5 September] 1857 – 19 September 1935) was a Russian and Soviet rocket scientist who pioneered astronautic theory. Along with the Frenchman Robert Esnault-Pelterie, the Transylvanian German Hermann Oberth and the American Robert H. Goddard, he is one of the founding fathers of modern rocketry and astronautics. His works later inspired leading Soviet rocket-engineers Sergei Korolev and Valentin Glushko, who contributed to the success of the Soviet space program.

Tsiolkovsky spent most of his life in a log house on the outskirts of Kaluga, about 200 km (120 mi) southwest of Moscow. A recluse by nature, his unusual habits made him seem bizarre to his fellow townsfolk.