Shot HA — the abbreviation standing for High Altitude — was the tenth nuclear detonation of Operation Teapot, fired on 6 April 1955 as an airdrop from a B-36H at 11,160 metres above Area 1 of the Nevada Test Site. It was a Los Alamos Scientific Laboratory development test of an air-to-air missile warhead, producing 3.2 kilotons. Because of the extreme altitude of the release, the device was parachute-retarded to allow the delivery aircraft sufficient time to reach a safe distance before detonation — the only parachute-retarded weapon drop ever conducted at the Nevada Test Site. The shot name HA was a straightforward abbreviation of its defining characteristic.