Soviet atomic bomb project: The Soviet Union tests its first atomic bomb, known as First Lightning or Joe 1, at Semipalatinsk, Kazakhstan.

The Soviet Union, officially the Union of Soviet Socialist Republics (USSR), was a transcontinental country that spanned much of Eurasia from its formation in 1922 until its dissolution in 1991. It was the world's third-most populous country, the largest by area, and bordered twelve other countries. A diverse multinational state, it was organized as a federal union of national republics, with the largest and most populous being the Russian Soviet Federative Socialist Republic (SFSR).

The world's flagship communist state, it was governed by the Communist Party under Marxism–Leninism, through soviet councils. The Soviet economy was also centrally planned. Its capital and largest city was Moscow.

AralSea1989 2014
AralSea1989 2014 (Source: Wikimedia Commons)
Alihanov Kurchatov Ioffe
Alihanov Kurchatov Ioffe (Source: Wikimedia Commons)
Model of F-1 reactor 01
Model of F-1 reactor 01 (Source: Wikimedia Commons)
W87 MIRV
W87 MIRV (Source: Wikimedia Commons)

Watch: 1922 - 1991: The Complete History Of The Soviet Union

From the Timeline - World History Documentaries channel.

Sources and further reading: Wikipedia — Soviet Union, Soviet atomic bomb project, Nuclear weapon, RDS-1 (CC BY-SA). Images: Wikimedia Commons.