Konstantin Tsiolkovsky Publishes Rocket Theory

In 1903, Konstantin Tsiolkovsky, a Russian schoolteacher and physicist, published his groundbreaking work "Exploration of Space Using Reactive Devices" in the Russian journal Nauchnoe Obozrenie (Science Review). This paper presented the first mathematical theory of rocket propulsion, including what became known as the Tsiolkovsky rocket equation, and established the theoretical foundations of modern spaceflight.