In 1957, the Soviet Union launched the world's first artificial satellite, ''Sputnik 1'', thus starting the Space Age. Russian cosmonaut Yuri Gagarin became the first human to orbit the Earth, aboard the ''Vostok 1'' manned spacecraft on 12 April 1961. Following the ousting of Khrushchev in 1964, another period of collective rule ensued, until Leonid Brezhnev became the leader. The era of the 1970s and the early 1980s was later designated as the Era of Stagnation, a period when economic growth slowed and social policies became static. The 1965 Kosygin reform aimed for partial decentralisation of the Soviet economy and shifted the emphasis from heavy industry and weapons to light industry and consumer goods but was stifled by the conservative Communist leadership. In 1979, after a Communist-led revolution in Afghanistan, Soviet forces invaded the country, ultimately starting the Soviet–Afghan War. The occupation drained economic resources and dragged on without achieving meaningful political results. Finally, the Soviets withdrew from Afghanistan in 1989 due to international opposition, persistent anti-Soviet guerrilla warfare, and a lack of support by Soviet citizens.