Between 1958 and 1975 , Johnston Atoll was used as an American national nuclear test site for atmospheric and extremely high-altitude nuclear explosions in outer space . In 1958 , Johnston Atoll was the location of the two " Hardtack I " nuclear tests firings . One on August 1 , 1958 , was codenamed " Hardtack Teak " , and one on August 12 , 1958 was codenamed " Orange " , and both tests detonated 3.8-megaton hydrogen bombs launched to high altitudes by rockets from Johnston Atoll
Hardtack Teak
Hardtack Teak
Johnston Atoll