Renovation Work At The Sayan-Shushenskaya GES, Russia

After Stalin's death and a short period of collective rule, new leader Nikita Khrushchev denounced the cult of personality of Stalin and launched the policy of de-Stalinization. Penal labor system was reformed and many prisoners were released and rehabilitated (lots of them posthumously). The general easement of repressive policies became known later as the Khrushchev thaw. At the same time, tensions with the United States heightened when the two rivals clashed over the deployment of the U.S. Jupiter missiles in Turkey and Soviet missiles in Cuba.
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 Vostok 1 manned spacecraft on 12 April 1961.
Following the ousting of voluntarist and erratic Khrushchev in 1964, another period of collective rule ensued, until Leonid Brezhnev became the leader. The era of 1970s and the early 1980s was designated later as the Era of Stagnation, a period when the economic growth slowed and social policies became static. The Kosygin reform, aimed into partial decentralization of the Soviet economy and shifting the emphasis from heavy industry and weapons to light industry and consumer goods, was stifled by the conservative Communist leadership.
In 1979 the Soviet forces entered Afghanistan at the request of its communist government. The occupation drained economic resources and dragged on without achieving meaningful political results. Ultimately the Soviet Army was withdrawn from Afghanistan in 1989 because of international opposition, persistent anti-Soviet guerilla warfare (enhanced by the U.S.), and a lack of support from Soviet citizens.