<P> The first theoretical proposal of space travel using rockets was published by Scottish astronomer and mathematician William Leitch, in an 1861 essay "A Journey Through Space". More well - known (though not widely outside Russia) is Konstantin Tsiolkovsky's work, "Исследование мировых пространств реактивными приборами" (The Exploration of Cosmic Space by Means of Reaction Devices), published in 1903 . </P> <P> Spaceflight became an engineering possibility with the work of Robert H. Goddard's publication in 1919 of his paper A Method of Reaching Extreme Altitudes . His application of the de Laval nozzle to liquid fuel rockets improved efficiency enough for interplanetary travel to become possible . He also proved in the laboratory that rockets would work in the vacuum of space; nonetheless, his work was not taken seriously by the public . His attempt to secure an Army contract for a rocket - propelled weapon in the first World War was defeated by the November 11, 1918 armistice with Germany . </P> <P> Nonetheless, Goddard's paper was highly influential on Hermann Oberth, who in turn influenced Wernher von Braun . Von Braun became the first to produce modern rockets as guided weapons, employed by Adolf Hitler . Von Braun's V - 2 was the first rocket to reach space, at an altitude of 189 kilometers (102 nautical miles) on a June 1944 test flight . </P> <P> Tsiolkovsky's rocketry work was not fully appreciated in his lifetime, but he influenced Sergey Korolev, who became the Soviet Union's chief rocket designer under Joseph Stalin, to develop intercontinental ballistic missiles to carry nuclear weapons as a counter measure to United States bomber planes . Derivatives of Korolev's R - 7 Semyorka missiles were used to launch the world's first artificial Earth satellite, Sputnik 1, on October 4, 1957, and later the first human to orbit the Earth, Yuri Gagarin in Vostok 1, on April 12, 1961 . </P>

When did the first rocket go into space