«Tewa» thermonuclear explosion, 5 Megatons, barge, Bikini Atoll, 5:46 a.m. July 21, 1956. This device, the «Bassoon Prime», was a «dirty» three stage design. The fission yield was 87%.
On July 16, 1945, in New Mexico’s Jornada del Muerto desert at 5:29 a.m., the U.S. conducted the first ever detonation of a nuclear device as part of the Manhattan Project.