History of the United States 6–3 decision in Korematsu v. United States Supreme Court case. Research and development took flight as well, best seen in the Manhattan Project, a secret effort to harness nuclear fission to produce highly destructive atomic bombs. From 1942 to 1946, the project was under the direction of Major General Leslie Groves of the U.S. Army Corps of Engineers. Nuclear physicist J. Robert Oppenheimer was the director of the Los Alamos Laboratory that designed the actual bombs. The first nuclear device ever detonated was an implosion-type bomb at the Trinity test, conducted at New Mexico's Alamogordo Bombing and Gunnery Range on
B46 nuclear bomb was redesignated the B53 nuclear bomb and W53 warhead. 50 B53 bombs were in US inactive reserves from 1997 to 2011, though none were actively deployed during that period. B46 nuclear bomb The B46 nuclear bomb (or Mk-46) was an American high-yield thermonuclear bomb which was designed and tested in the late 1950s. It was never deployed. Though originally intended to be a production design, the B46 ended up being only an intermediate prototype which was test fired several times. These prototypes were known as TX-46 units (Test/Experimental). The B46 design roughly weighed 8,120 pounds and was about 37 inches