Little Boy

Little Boy was a uranium-235 gun-type fission bomb detonated over Hiroshima on August 6, 1945. It was the first nuclear weapon used in warfare.

Gun-type nuclear weapon: A fission weapon that drives one subcritical fissile mass into another to create a supercritical assembly. Little Boy used this comparatively simple assembly method to initiate its nuclear explosion.
Manhattan Project: The Allied research and production program that developed the first nuclear weapons during World War II. Little Boy was one of the weapons produced by this secret program.
Paul Tibbets: The U.S. Army Air Forces pilot who commanded the Hiroshima bombing mission. Tibbets piloted the Enola Gay when it released Little Boy.
Atomic bombing of Hiroshima: The U.S. nuclear attack on Hiroshima on August 6, 1945, during World War II. This was the attack in which Little Boy detonated.
Atomic bombings of Hiroshima and Nagasaki: The two U.S. nuclear attacks on Japanese cities in August 1945. Little Boy's detonation was the first of these two attacks.
Uranium-235: A fissile isotope of uranium capable of sustaining a fast-neutron chain reaction. This isotope supplied the fissile material in Little Boy's bomb core.
Los Alamos Laboratory: The New Mexico laboratory where scientists designed and assembled the first atomic bombs. The laboratory developed Little Boy's weapon design and prepared it for use.
Enola Gay: The Boeing B-29 bomber that carried the Hiroshima atomic bomb mission. This aircraft delivered Little Boy to Hiroshima.
Hiroshima: A Japanese city that was devastated by a U.S. atomic bombing on August 6, 1945. Little Boy exploded over the city, causing mass destruction and loss of life.
Hibakusha: Japanese survivors of the atomic bombings of Hiroshima and Nagasaki. Hibakusha experienced the blast, burns, radiation exposure, and lasting aftermath of Little Boy.

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