Nuclear technology the element plutonium possesses an isotope that is sufficiently unstable for this process to be usable. Terrestrial plutonium does not currently occur naturally in sufficient quantities for such use, so it must be manufactured in a nuclear reactor. Ultimately, the Manhattan Project manufactured nuclear weapons based on each of these elements. They detonated the first nuclear weapon in a test code-named "Trinity", near Alamogordo, New Mexico, on July 16, 1945. The test was conducted to ensure that the implosion method of detonation would work, which it did. A uranium bomb, Little Boy, was dropped on the Japanese city Hiroshima on
Nuclear arms race megatons. On October 30, 1961, the Soviets detonated a hydrogen bomb with a yield of approximately 58 megatons. With both sides in the "cold war" having nuclear capability, an arms race developed, with the Soviet union attempting first to catch up and then to surpass the Americans. Strategic bombers were the primary delivery method at the beginning of the Cold War. Missiles had long been regarded the ideal platform for nuclear weapons, and were potentially a more effective delivery system than bombers. Starting in the 1950s, medium-range ballistic missiles and intermediate-range ballistic missiles ("IRBM"s) were developed for delivery of tactical