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Science29 August 1949

The First Soviet Atomic Bomb

Also called: RDS-1, First Lightning

On 29 August 1949 the Soviet Union tested its first atomic bomb at Semipalatinsk in Kazakhstan. America’s nuclear monopoly ended after four years, and the nuclear arms race between the two powers began.

Casing of RDS-1, the first Soviet atomic bomb — Polytechnical Museum, Moscow
Casing of RDS-1, the first Soviet atomic bomb — Polytechnical Museum, Moscow

Mikhail (Vokabre) Shcherbakov · CC BY-SA 2.0 · Source

After Hiroshima Stalin ordered the bomb rushed, with the secret-police chief Beria in charge. Using design information stolen by spies inside the Manhattan Project such as Klaus Fuchs, Soviet scientists built RDS-1, a plutonium bomb almost identical to America’s Fat Man.

It exploded on the Semipalatinsk steppe on 29 August 1949, and the United States detected it in September from radioactive particles in the air. Shaken by a Soviet success years earlier than expected, the US decided the next year to build the hydrogen bomb; Oppenheimer, who opposed it, lost his security clearance in 1954. Some 450 more tests followed at Semipalatinsk until 1989, leaving its people with lasting harm.

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States and rulers at the time
Soviet Union — Leader Joseph Stalin
Places
Semipalatinsk Test Site

People

  • J. Robert Oppenheimer1904 – 1967

    related figure · American physicist who directed the Los Alamos laboratory and led the building of the atomic bomb — the "father of the atomic bomb" — and after the war opposed the hydrogen bomb

Before and after

Earlier
1946 US–Soviet Joint Commission
Later
1957 Launch of Sputnik 1

Themes that include this event

  • The Birth of the Atomic Bomb1938 – 1949

    From the discovery of fission to the first Soviet bomb — Einstein’s letter, the Manhattan Project, the Trinity test, Hiroshima and Nagasaki, and the dawn of the nuclear age