On the 29th August 1949, the Soviet Union successfully detonated its first nuclear weapon codenamed RDS-1 and nicknamed First Lightning. The explosion had the power of 22 kilotons of TNT, and was 50% more destructive than its designers had expected.
The USSR started its nuclear program in 1943 after discovering the USA, Britain and Canada had begun bomb development. Assisted by intelligence from sources inside the USA’s Manhattan Project, the Soviet Union’s program developed quickly as the Soviets were able to replicate American successes while avoiding some of their costlier mistakes. Consequently, although the majority of Cold War academics accept that the USSR’s success had a lot to do with domestic expertise they recognise that intelligence helped to reduce the time it took for them to develop the bomb.
Work was accelerated after the bombings of Hiroshima and Nagasaki in secret, purpose-built cities dedicated to the nuclear program known as Atomgrads. By 1949 the Soviets had developed two types of bomb, but opted to detonate the simpler of the two designs first since it was similar in design to the successful Fat Man bomb that was dropped on Nagasaki.
The RDS-1 test was conducted in secret in an attempt to avoid the USA increasing its own nuclear program, but the US Air Force began to detect radioactive fallout from the explosion a few days later and tracked the trail. Soviet success had occurred up to 4 years ahead of Western estimates, and the knowledge that the USSR now had ‘the bomb’ dramatically increased tensions in the early years of the Cold War.