STARFISH PRIME

On 9 July 1962, an event which would have important ramifications for two Soviet cosmonauts and an American astronaut got underway on Johnston Island in the Pacific Ocean. It was part of a joint effort between the Defense Atomic Support Agency (DASA) and the Atomic Energy Commission (AEC) and was known under its umbrella designation of ‘Operation Dominic’. Its objective, nicknamed ‘Starfish Prime’, was to detonate a thermonuclear warhead some 400 km above Earth’s surface. The testing of such devices in both the Pacific and Nevada in 1962-63 sought to evaluate new weapons designs, their effects and their reliability. Its timing was crucial: in August 1961, Nikita Khrushchev had announced the end of a three – year moratorium and resumed Soviet weapons testing a few weeks later, when the most powerful hydrogen bomb ever built – nicknamed ‘Ivan’ by the Russians – was detonated over the Novaya Zemlya archipelago in the Arctic Ocean.

Both it and Operation Dominic would arouse much condemnation and, indeed, despite their own efforts, the Soviets would request diplomatic assurances that the Americans refrain from their nuclear weapons testing whilst cosmonauts Nikolayev and Popovich were in orbit. Starfish Prime was one of five tests conducted by the United States ‘in outer space’, although an initial launch attempt on 20 June 1962 had failed when its Thor carrier missile experienced an engine malfunction, crashed, showered the Johnston area with radioactive metal and caused ‘‘slight’’ nuclear contamination.

Less than three weeks later, atop another Thor, the test commenced. Its warhead produced an explosive yield equivalent to 1.4 megatons of TNT and, although too high and too far beyond the ‘sensible’ atmosphere to create a fireball, triggered a whole host of problems back on Earth. Across Hawaii, for example, some 1,500 km

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to the east of Johnston Island, the effects of its electromagnetic pulse caused 300 street lights to fail, television sets and radios to malfunction, burglar alarms to sound in unison and power lines to fuse. On the westernmost Hawaiian island of Kauai, telephone links with the other islands were severed when a microwave link burned out and much of the Pacific skyline was lit by an eerie, man-made aurora, lasting for more than seven minutes. Observers in the far-off Samoan Islands, more than 3,200 km from the blast, even recorded the aurora on film.

According to a witness of the test, whose remarks were published in August, “a brilliant white flash burned through the clouds” at the stroke of 9:00 am, “rapidly changing to an expanding green ball of irradiance extending into the clear sky above the overcast. From its surface extruded great white fingers, resembling cirrostratus clouds, which rose to 40 degrees above the horizon in sweeping arcs turning downward toward the poles and disappearing in seconds to be replaced by spectacular concentric cirrus-like rings moving out from the blast at tremendous initial velocity, finally stopping when the outermost ring was 50 degrees overhead… All this occurred, I would judge, within 45 seconds. As the greenish light turned to purple and began to fade at the point of burst, a bright red glow began to develop on the horizon. . . expanding inward and upward until the whole eastern sky was a dull, burning-red semicircle…”

Despite the risk, ‘rainbow bomb parties’ were offered by Hawaiian hotels on their rooftops to view the effects of the Starfish Prime detonation. By the end of July, however, circumstances had changed markedly. Another test, ‘Bluegill Prime’, suffered an engine failure on the pad. It was detonated, after ignition, by range safety officers, completely destroying both it and the launch facility. More than three months of repairs – and extensive decontamination – would follow. The largest nuclear weapons testing project ever conducted by the United States would also be its last in the high atmosphere. In August 1963 and coming into effect just two months later, the Limited Test Ban Treaty was signed by the United States, the Soviet Union and Britain to restrict all future detonations to underground. For a time, at least, it helped to enforce a dramatic slowdown of the arms race between the superpowers.