Gagarin, Yury Alekseyevich(1934-1968), Soviet cosmonaut, born near Smolensk. After graduating from technical and vocational schools, he enrolled at the Soviet air force cadet training centre at Orenburg, graduating as a pilot in 1957. On April 12, 1961, Gagarin, then a major in the air force, became the first man to travel in space when he rode aboard the Earth satellite Vostok (later referred to as Vostok 1) on a 27,400 km/hr (17,000 mph) single orbit of the Earth. The flight lasted 1 hr 48 min, on an elliptical course having an apogee of 327 km (203 mi) and a perigee of 180 km (112 mi). He was killed in the crash of a test aircraft.