Kaluga (Russian: Калу́га, .mw-parser-output .IPA-label-small{font-size:85%}.mw-parser-output .references .IPA-label-small,.mw-parser-output .infobox .IPA-label-small,.mw-parser-output .navbox .IPA-label-small{font-size:100%}IPA: [kɐˈɫuɡə]) is a city and the administrative center of Kaluga Oblast, Russia. It stands on the Oka River 150 kilometers (93 mi) southwest of Moscow. Its population was 337,058 at the 2021 census.[14] Kaluga's most famous resident, the space travel pioneer Konstantin Tsiolkovsky, worked there as a school teacher from 1892 to 1935. The Tsiolkovsky State Museum of the History of Cosmonautics in Kaluga is dedicated to his theoretical achievements and to their practical implementations for modern space research, hence the motto on the city's coat of arms: Колыбель Космонавтики, Kolybélʹ kosmonávtiki ("The Cradle of Space-Exploration").