The Vostok program was the first human spaceflight program of the Soviet Union, aimed at sending astronauts, known as cosmonauts, into space. It began in the late 1950s and successfully launched its first mission, Vostok 1, on April 12, 1961, carrying Yuri Gagarin, the first human to orbit the Earth. The program included a total of six crewed flights between 1961 and 1963. Each mission helped gather valuable data about space travel and human endurance in space, paving the way for future programs like Voskhod and Soyuz. The Vostok program marked a significant milestone in the Space Race.