Nuclear fission Mexico, which was the scientific hub for research on bomb development and design. Other sites, notably the Berkeley Radiation Laboratory and the Metallurgical Laboratory at the University of Chicago, played important contributing roles. Overall scientific direction of the project was managed by the physicist J. Robert Oppenheimer. In July 1945, the first atomic explosive device, dubbed "Trinity", was detonated in the New Mexico desert. It was fueled by plutonium created at Hanford. In August 1945, two more atomic devices – "Little Boy", a uranium-235 bomb, and "Fat Man", a plutonium bomb – were used against the Japanese cities of Hiroshima
Nuclear weapons and the United Kingdom the year. During Operation Hurricane, an atomic bomb was detonated on board the frigate anchored in a lagoon in the Monte Bello Islands in Western Australia on 3 October 1952. Britain thereby became the third country to develop and test nuclear weapons. This led to the development of the first deployed weapon, the Blue Danube free-fall bomb. It had a diameter, 32 explosive lens implosion system with a levitated pit suspended within a natural uranium tamper. The warhead was contained within a bomb casing measuring diameter and long, and it weighed approximately , of which about was high explosive. The