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
Mark 5 nuclear bomb have been reported. As with many early US nuclear weapon designs, the fissile material or pit could be kept separately from the bomb and assembled into it during flight. This technology is known as In Flight Insertion or IFI. The Mark 5 had an automatic IFI mechanism which could insert the pit into the center of the explosive assembly from a storage position in the bomb nose. The image here shows the doors to that nose compartment open. The Mark 5 was in service from 1952 to 1963. The W5 saw service from 1954 to 1963. Approximately 72 Mark 5