Konstantin Tsiolkovsky was a Russian scientist and pioneer in astronautics, born in 1857. He is best known for his work on the theoretical foundations of space travel and rocketry. Tsiolkovsky developed the concept of the rocket equation, which describes how rockets can achieve the necessary velocity to escape Earth's gravity. His ideas laid the groundwork for modern space exploration and inspired future scientists and engineers. Tsiolkovsky also envisioned the use of space stations and the colonization of other planets, making significant contributions to the field of aerospace engineering and influencing figures like Wernher von Braun and Sergei Korolev.