Ballpark Estimate: $2 Billion (1945 dollars); $25 Billion (2008 dollars)

At the Alamogordo Bombing Range, now the White Sands Missile Range near Socorro, New Mexico, it was 5:00 a.m. The weather that morning of July 16, 1945 was clear and most importantly; wind conditions were low, ideal for localizing the fallout of radioactive material from the expected cloud of debris. Many high-level scientists and military personnel waited anxiously at scattered sites around ground zero and from bunkers ten and seventeen miles away.

The First Blast

Suddenly, at 5:29 a.m., the morning calm was broken by an enormous flash that lit up the surrounding mountains and could be seen as far as 150 miles. At the same time, an enormous explosion rumbled across the desert as a huge orange fireball, expanding into a pulsating red as it cooled, began shooting upward at around 360 feet per second. This was quickly followed by a swirling mushroom-shaped cloud that reached an estimated 50,000 to 70,000 feet above ground zero. Called the Trinity Test, this 18-20-kiloton blast was the culmination of years of research and development that ushered in the so-called Atomic Age.

Early Development and Experiments

The development of the Atomic Bomb was actually the result of a convergence of political and scientific events beginning in the 1930s. The advances in understanding the nature of the atom and its role as a source for immense amounts of energy coincided with the rise of fascist governments in Europe. These parallel activities aroused much fear that Nazi Germany could become technologically capable of developing a weapon that used the recently discovered nuclear fission techniques.

The earlier experiments of the 1930s were instrumental in discovering methods for spitting the uranium atom. These discoveries pointed out that splitting the nucleus of a single uranium atom was possible by bombarding the atom with neutrons. By splitting the atom’s nucleus large amounts of energy, equivalent to 200,000,000 electron volts, could be released as well as additional neutrons, a process called nuclear fission. This release of nuclear energy was the conversion of about .1 percent of the mass of the uranium atom into energy, as previously postulated by Albert Einstein.

Fears of Germany Splitting the Atom First

There was also the possibility that these additional freed neutrons, under specific conditions, could trigger a nuclear chain reaction which had the potential of releasing even greater amounts of energy. It was this scenario that prompted wide spread fears within the scientific community that grave consequences could result if Nazi Germany became the first to use this new nuclear technology.

Los Alamos and Oak Ridge

As a result of their dire warnings to the White House, an organized effort by the U.S. to investigate the feasibility of building a nuclear weapon began in earnest in 1943. Called the Manhattan Project, three principal and top-secret sites were established to carry out further research and development by such notable physicists as Leo Szilard, Enrico Fermi, Edward Teller, and Robert Oppenheimer, who would direct the project. These sites were the plutonium-production facility at Richland, Washington, the uranium-enrichment facility at Oak Ridge, Tennessee, and the weapons research and design laboratory located at Los Alamos, New Mexico.

Components from over thirty other sites would be delivered to the scientists at the Los Alamos complex, who were charged with the design and assembly of the bomb itself. The coordination of these highly classified facilities was the responsibility of the North Atlantic Division of the U.S. Army Corps of Engineers located in Oak Ridge. In fact, the existence of the three sites was so secret that not even the governors of the respective states knew of their presence until after the Hiroshima bomb was dropped.

The Final Design

The final design agreed to at Los Alamos for the Atomic Bomb detonated at the Trinity test site was an “implosion” device. In place of uranium-235 which was more difficult to produce, the principal material within the bomb was plutonium-239, a metal produced at the Washington site in a nuclear reactor called a breeder reactor. The enriched plutonium material was then further processed at Los Alamos to form an approximately 13 lb. sphere the size of a softball that would be the core of the bomb.

For the chain reaction to occur within the core, the plutonium sphere had to be compressed equally over its entire surface so that the density of the sphere would increase significantly and transform the plutonium into a smaller and denser “critical mass”. This compression was accomplished by detonating precisely-placed igniters located on the surface of an explosive material surrounding the sphere thereby forcing the core to collapse on itself.

To direct this explosive energy inward toward the core, specially shaped charges were designed with numerous explosive “lenses” to produce the precise spherical shock wave necessary to compress the plutonium sphere into its critical mass. Under this scenario, nuclear fission would occur within the critical mass causing an enormous self-sustaining chain reaction by the freed neutrons resulting in a super-massive release of energy – the atomic explosion.

What Was the Total R&D Cost?

Needless to say, when the Manhattan Project was given permission to use the Cost To Develop An Atomic Bombhighest wartime priority rating by the War Production Board, the cost was no object. Besides the customary human resource expenses for more than 130,000 employees, the total costs included funding for such projects as the construction of a uranium isotope separation plant at Oak Ridge, Tennessee, construction of research and development facilities at Oak Ridge and Los Alamos, and plutonium production reactors in Washington. Also for such work as engineering the first artificial, self-sustaining, nuclear chain reaction, for conducting neutron experiments, research that produced plutonium-239, and research into gaseous diffusion and electromagnetic separation as uranium enrichment methods, just to mention a few of the Los Alamos and university research projects .

The total estimated cost of the Manhattan Project in 1945 dollars was $2 Billion ($25 Billion in 2008 dollars).