Nuclear fission the Manhattan Project during World War II (September 1, 1939 – September 2, 1945) carried out most of the early scientific work on fission chain reactions, culminating in the three events involving fission bombs that occurred during the war. The first fission bomb, codenamed "The Gadget", was detonated during the Trinity Test in the desert of New Mexico on July 16, 1945. Two other fission bombs, codenamed "Little Boy" and "Fat Man", were used in combat against the Japanese cities of Hiroshima and Nagasaki in on August 6 and 9, 1945 respectively. Even the first fission bombs were thousands of
B90 nuclear bomb diameter and 118 inches long, and weighed 780 pounds. The B90 had a design yield of 200 kilotons. The B90 was cancelled in September 1991 along with the W89 and W91 nuclear warheads and AGM-131 SRAM II and SRAM-T missile models. No B90 production models were built, though test units may have been; US nuclear weapon testing continued until 1992. B90 nuclear bomb The B90 was an American thermonuclear bomb designed in the mid-to-late 1980s and cancelled prior to introduction into military service due to the end of the Cold War making further nuclear weapon development unnecessary. The B90 design