Atomic detonation of 27 kilotons on May 8, 1953 at the Atomic Energy Commission's Nevada Proving Ground. The test device, codenamed Encore, was detonated at 8:30 local time by performing an airdrop of a Mk-6D bomb from 19,000 feet with a B-50 Superfortress over Area 5 at the Nevada Test Site. At 2,423 feet, the bomb detonated, although it was fifteen feet west and nine hundred and thirty seven feet south of its designated target. The estimated yield of the weapon was 30-36 kilotons, although it yielded twenty-seven kilotons. Operation Upshot-Knothole was a series of eleven nuclear test shots conducted in 1953 at the Nevada Test Site.