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
B83 nuclear bomb maneuvering space vehicles to "knock" an asteroid off course, should it pose a risk to the Earth. B83 nuclear bomb The B83 thermonuclear weapon is a variable-yield unguided bomb developed by the United States in the late 1970s, entering service in 1983. With a maximum yield of , it is the most powerful nuclear free-fall weapon in the United States arsenal. It was designed at Lawrence Livermore National Laboratory, and the first underground test detonation of the production B83 took place on 15 December 1984 in Nevada at Area U19ac. The B83 was based partly on the earlier B77 program,