Complex sentence: There is a Tsiolkovskiy Museum in Kaluga dedicated to his theoretical achievements and their practical implementations for modern space research, hence the motto on the city's coat of arms: "The Cradle of Space Exploration".
Split into simpler sentences: There is a Tsiolkovskiy Museum in Kaluga dedicated to his theoretical achievements and their practical implementations for modern space research. That's why the city coat of arms has the slogan: "The Cradle of Space Exploration".