The Vostok programme (Russian: Восток, IPA: [vɐˈstok], Orient or East) was a Soviet human spaceflight project to put the first Soviet citizens into low Earth orbit and return them safely. Competing with the United States Project Mercury, it succeeded in placing the first human into space, Yuri Gagarin, in a single orbit in Vostok 1 on April 12, 1961. The Vostok capsule was developed from the Zenit spy satellite project, and its launch vehicle was adapted from the existing R-7 Semyorka intercontinental ballistic missile (ICBM) design. The name "Vostok" was treated as classified information until Gagarin's flight was first publicly disclosed to the world press.