Manhattan Project

By pstoaks

  • Einstein-Szilárd Letter

    Einstein-Szilárd Letter
    Leó Szilárd pens a letter that is signed by Albert Einstein and addressed to President Roosevelt. It warns of the potential of using nuclear fission as a weapon. Strongly advising the President to fund research into it, as it was believed Nazi Germany may also be exploring the possibilities.

  • WW2 Begins

    WW2 Begins
    Germany invades Poland. France and Great Britain declare war on Germany two days later.
  • Period: to

    Advisory Committee on Uranium

    • October 11 1939 Economist Alexander Sachs meets with President Roosevelt and delivers the Einstein-Szilárd letter. Roosevelt authorizes the creation of the Advisory Committee on Uranium
    • October 21 1939 The Advisory Committee on Uranium have their first meeting. $6000 is budgeted for fission experiments.
    • June 12 1940 The National Defense Research Committee is created to organize scientific resources for war and absorbs the Uranium Committee and continues research on fission of uranium.

  • Plutonium

    Plutonium
    • A research group headed by Glenn T. Seaborg discovers plutonium.
    • By May, Seaborg proves plutonium is more fissionable than uranium

  • Japan Attacks!

    Japan Attacks!
    • Japan attacks a US military installation at Pearl Harbor, HI
    • The next day the US officially declares was on Japan
    • Three days later war is declared against Germany and Italy

  • The Bombs a Go

    The Bombs a Go
    • President Roosevelt approves development of the atomic bomb.
    • Arthur Compton creates the Metallurgical Laboratory (Met Lab) at the University of Chicago to research and use the new element plutonium.

  • Manhattan Engineering District

    Manhattan Engineering District
    • The Army Corps of Engineers office in New York City is opened and officially given the name Manhattan Engineering District. From then on the endeavor will be know as the Manhattan Project.
    • Shortly thereafter US army Brigadier General Leslie Groves is appointed head of the Manhattan Engineer District

  • Site X

    Site X
    • 56,000 acres in Oak Ridge, Tennessee is acquired for Site X
    • It becomes a secret laboratory and uranium enrichment site
    • Three enrichments plants will be built: Y-12 Electromagnetic Isotope Separation Plant, K-25 Gaseous Diffusion Plant, S-50 Liquid Thermal Diffusion Plant

  • Site Y

    Site Y
    • Los Alamos, NM is chosen for site Y.
    • It is a secret laboratory for the development and construction of the atomic bomb.
    • J. Robert Oppenheimer is chosen a laboratory director.

  • We're nuclear

    We're nuclear
    • Under Enrico Fermi's leadership and design, The Chicago Pile-1 reactor goes critical at the University of Chicago.
    • It achieves the first ever self-sustaining nuclear chain reaction.
    • Fermi describes the Pile-1 reactor as " a crude pile of black bricks and wooden timbers.
    • The reactor contained 45,000 ultra-pure graphite blocks weighing 360 short tons and was fueled by 5.4 short tons of uranium metal and 45 short tons of uranium oxide.

  • Site W

    Site W
    • Hanford, WA is chosen for Site W
    • It is a secret plutonium production complex
    • Three nuclear reactors and three plutonium processing plants will be built by the end of WW2

  • Thin Man out, Fat Man in

    Thin Man out, Fat Man in
    • The development of the "Thin Man" bomb is scraped when Emilio Segrè discovers the spontaneous fission rate of plutonium is too high for a gun-type weapon.
    • Making a workable implosion design (Fat Man) becomes the top priority.
    • Design of a uranium gun-type weapon (Little Boy) continues.

  • RIP FDR

    RIP FDR
    • President Roosevelt dies. Harry Truman succeeds FDR
    • He first learns of the Manhattan Project the next day

  • The Gadget

    The Gadget
    • The Gadget, an implosion-style plutonium-based nuclear weapon, is successfully detonated at the Trinity test site (Alamogordo, NM).
    • It was the first ever nuclear explosion.
    • USS Indianapolis is on its way to Tinian with the components of the "Little Boy" on board.

  • Potsdam Declaration

    Potsdam Declaration
    • Truman issues the Potsdam Declaration, warning Japan of "prompt and utter destruction" if they don't surrender.
    • Japan does not surrender at that time.

  • Little Boy

    Little Boy
    • The B-29 bomber Enola Gay drops Little Boy, a untested gun-type uranium-235 weapon, on Hiroshima.

  • Nagasaki

    Nagasaki
    • The B-29 bomber Bockscar drops "Fat Man", an implosion-type plutonium bomb, on Nagasaki.
    • Nagasaki was the secondary target. The primary target, Kokura, was obscured by clouds and smoke.

  • Surrender!

    Surrender!
    • Japan announces their surrender
    • Three weeks later Japan formally signs the Instrument of Surrender

  • Atomic Energy Act

    Atomic Energy Act
    • President Truman signs the Atomic Energy Act, establishing the Atomic Energy Commission
    • This transfers the United States' nuclear program from military to civilian control.

  • AEC takes over

    AEC takes over
    • The Atomic Energy Commission take control of the Manhattan Engineer District
    • Seven months later the Manhattan Engineer District is abolished, formally ending the Manhattan Project