The First Hydrogen Bomb

The first US airdrop of a thermonuclear bomb happened on May 20th, 1956.

The first hydrogen bomb dropped from the air exploded with a force estimated as equal to a minimum of fifteen million tons of TNT and created a fireball at least four miles wide and brighter than 500 suns.

It was described as ‘by far the most stupendous release of explosive energy on earth so far.’ Dropped from an American B52 jet bomber named the Barbara Grace, flying at around 45,000ft above Namu Island in the Bikini Atoll in the Pacific, it was set off at 5.51 a.m. local time at an altitude of 10,000ft – to minimize the radioactive fallout – in view of some 13,500 people. There were thirty or more observers in reconnaissance aircraft and thousands of civilian observers and journalists in a fleet of ships thirty miles or so from the scene. The bomb missed its target by about four miles. The bomber itself was fifteen miles away by the time the bomb went off and got away safely, though all the aircraft involved were struck by a tremendous shock wave from the explosion.

The correspondent of the London Times, watching through high-density goggles from one of the ships, saw the fireball shoot up into the air, followed almost instantly by a giant pillar of fire and then by an enormous mushroom cloud climbing up and spreading out until ‘it appeared as though it would envelop the entire earth’. It glowed with colours from deep purple to orange and pink at the top and was eventually more than twenty-five miles high and a hundred miles across.

Theoretical physicists in the USA had considered a ‘super’ bomb even before the atomic bomb was developed. Robert Oppenheimer and Edward Teller were already discussing thermonuclear weapons in 1942 and when the Los Alamos laboratory in New Mexico was established under Oppenheimer in 1943, Teller led a ‘Super’ research programme. There were serious theoretical problems and the atomic bomb was given priority, but work on the ‘Super’ was continued after the war by a group which included the Soviet spy Klaus Fuchs. The first successful American test was conducted in the Pacific in 1952, the first Soviet test in the following year. An American crash programme under Teller was ready to drop the first H-bomb ever launched from an aircraft in May 1956. William Lawrence, an American authority who watched the test, described it as ‘an effective substitute for war’.