The First Atomic Bomb Mission: Trinity B-29 Operations Three Weeks before Hiroshima

Article excerpt

On July 16, 1945, the world changed forever, but the moment was witnessed by little more than 400 observers. Before dawn at a remote desert test site in New Mexico, history's first atomic bomb was exploded, culminating a top secret project codenamed Trinity. It was 50 percent more powerful than the bomb that soon would be dropped on Hiroshima and almost equal to the one dropped on Nagasaki a few days later. As events unfolded, Trinity's success meant an end to World War II without an Allied invasion of Japan, saving untold numbers of lives. But even though this epic event has been the subject of many scholarly works for more than sixty years, one important chapter of the Trinity story is still incomplete. It is the account of the fewer than two dozen men who witnessed the blast aloft in two B-29 bombers, exposed to uncertain and potentially deadly risks.

This paper identifies those intrepid flyers, why they were aboard, and what they saw. Most importantly, for the first time it identifies the airmen who crewed those Trinity flights, why they were selected, and how they prepared for their mission. Based on newly available personal military records, overlooked primary sources, and prior scholarship, this paper extends the important, but still unfinished, story of the U.S. 216th Army Air Forces Base Unit (Special) and its leading role in creating the atomic bombs that decisively ended World War II. (1) This is particularly significant because no 216th records for the critical year 1945 have yet been found by this author in any of the principal national archives. Most distressing, the Air Force Historical Research Agency, primary repository of Air Force historical documents, has no records of the 216th's finest hours. In 2013, the Agency wrote to an independent researcher, "For some reason, the histories for the 216thAAF BU goes [sic] to September 1944 then does [sic] not pick up again until January 1946." (2) One result is that official AAF manifests for the Trinity flights are missing and the author has had to reconstruct them.

The Manhattan Project

Many talented people helped create the first atomic bombs, but arguably the two most important were U.S. Army General Leslie R. Groves, head of the atomic bomb project (codenamed Manhattan Engineer District), and J. Robert Oppenheimer, scientific director of Los Alamos Laboratory (LAL), where breakthrough science and engineering transformed atomic theory into reality. (3) Oppenheimer's role began in mid-1942, a few months before Groves chose him to lead LAL. Six months later, the site for the laboratory had been chosen, construction was underway, and LAL personnel began to move in:

Jun 42 Oppenheimer appointed Scientific Director of the Development of Substitute Materials Project, forerunner of Manhattan.

Sep 42 Groves assumes command of Manhattan.

Oct 42 Groves decides to centralize atomic bomb research at a single location and selects Oppenheimer to lead it.

Nov 42 LAL site chosen in New Mexico.

Apr 43 Initial research staffs move to LAL.

Manhattan's goal was to produce several atomic bombs in order to credibly threaten the Axis powers with repeated atomic attacks as necessary to force their surrender. Later events validated that goal, but achieving it depended on solving the most profound unknowns of nuclear science.

Manhattan's Scientific Challenge

At the risk of oversimplifying, the immense power of an atomic bomb is the result of massive amounts of energy released when a particular material achieves critical mass, which triggers the nucleus of an atom to split apart--fission--releasing energy that creates an instantaneous, self-sustaining chain reaction of splitting nuclei within all the other atoms in the material, thereby releasing even more energy and creating an unprecedented blast. Researchers had determined that the most promising materials to produce that result were the elements Uranium-235 (U-235) and Plutenium-239 (Pu-239), but as potential weapons, the two elements had almost mirror-image advantages and disadvantages. …