The RDS-1, also known as Izdeliye 501 and First Lightning, was the nuclear bomb used in the Soviet Union's first nuclear weapon test. The United States assigned it the code-name Joe-1, in reference to Joseph Stalin. It was detonated on 29 August 1949 at 7:00 a.m., at the Semipalatinsk Test Site, Kazakh SSR, after top-secret research and development as part of the Soviet atomic bomb project.
RDS-1
The mushroom cloud from the first RDS-1 test (1949)
Nuclear weapons tests are experiments carried out to determine the performance, yield, and effects of nuclear weapons. Testing nuclear weapons offers practical information about how the weapons function, how detonations are affected by different conditions, and how personnel, structures, and equipment are affected when subjected to nuclear explosions. However, nuclear testing has often been used as an indicator of scientific and military strength. Many tests have been overtly political in their intention; most nuclear weapons states publicly declared their nuclear status through a nuclear test.
The mushroom cloud from the Castle Bravo thermonuclear weapon test in 1954, the largest nuclear weapons test ever conducted by the United States
Subcritical experiment at the Nevada National Security Site
The Phoenix of Hiroshima (foreground) in Hong Kong Harbor in 1967, was involved in several famous anti-nuclear protest voyages against nuclear testing in the Pacific.
The first atomic test, "Trinity", took place on July 16, 1945.