Trinity was the code name for the first detonation of a nuclear weapon, conducted by the United States Army at 5:29 am on Monday, July 16, 1945, as part of the Manhattan Project in the Jornada del Muerto desert about 35 miles southeast of Socorro, New Mexico, on what was then the USAAF Alamogordo Bombing and Gunnery Range. The only nearby structures were the McDonald Ranch House and its ancillary buildings, which scientists used as a clean room for assembling bomb components, while a base camp held 425 people present for the test. J. Robert Oppenheimer, director of the Los Alamos Laboratory, assigned the code name, inspired by the poetry of John Donne. The device tested was an implosion-design plutonium bomb informally nicknamed The Gadget, the same design later used for the Fat Man bomb detonated over Nagasaki, Japan, on August 9, 1945. Because the design was complex and there were concerns about whether it would work, Los Alamos Laboratory undertook a major effort and decided to conduct the first nuclear test, which was planned and directed by Kenneth Bainbridge, while the simpler uranium bomb Little Boy did not require a test. The stakes included a possible invasion of Japan, the lives of thousands of American and Allied troops and millions of Japanese, the redeployment of American troops from Europe to the Pacific, Soviet contemplation of an invasion of Northern Japan, and President Truman's desire to end the war as soon as possible with the fewest casualties after the battle for Okinawa. The Fat Man plutonium core and its initiator left Kirtland Field for Tinian Island on July 26, 1945, in a C-54 transport plane and arrived on July 28; that same day, three specially modified B-29s carrying three Fat Man bomb assemblies, each encased in an outer ballistic shell, also departed Kirtland Field and reached Tinian on August 2, 1945. The 320th Troop Carrier Squadron, assigned to the 509th Composite Group and nicknamed The Green Hornet Line, provided transportation of troops and material, and a Douglas C-54 Skymaster cargo plane of the 320th TCS transported the Fat Man core and initiator.
