Soviet postage stamp commemorating and signed by Yuri Gagarin. Soviet cosmonaut Yuri Gagarin (1934-1968) was the first human in space, orbiting the Earth in the Vostok 1 spacecraft on 12th April 1961. Following this historic spaceflight, Gagarin became a hero in the Soviet Union and famous worldwide. Gagarin died in an aircraft training flight in 1968, and his ashes were interred with full military honours in the Kremlin Wall.