History Points, August 29: Soviet Union test its first atomic bomb

On August 29, 1949 Soviet Union tested its first atomic bomb, right 4 years after the American atomic bomb attack on Japan. Code named Izdeliye 501 or First Lightening, the 22 kiloton atomic bomb was detonated at the Semipalatinsk Test Site in Kazakhstan. It is thought that the bomb was a replica of the Fat Man bomb, the plans for which were brought to USSR by spies at the Manhattan project. The US called the Soviet bomb, Joe-1.
In order to measure the effects of the blast, the Soviet scientists constructed buildings, bridges, and other civilian structures in the vicinity of the bomb. They also placed animals in cages nearby so that they could test the effects of nuclear radiation on human-like mammals. The atomic explosion, which at 20 kilotons was roughly equal to “Trinity,” the first U.S. atomic explosion, destroyed those structures and incinerated the animals.