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Kaluga was the city where Tsiolkovsky spent the majority of his life. He lived there from 1880 until his death in 1935. During his time in Kaluga, Tsiolkovsky developed his theories on space travel and rocketry. He also wrote extensively on these topics, publishing over 500 papers and books. Tsiolkovsky's work laid the foundation for the development of modern rocketry and space exploration.