The early period of nuclear testing in the atmosphere was a time that will not be seen again. It was the beginning of an era of unparalleled scientific activity and of worldwide emotional and intellectual adjustment to the knowledge that power of unimaginable magnitude, locked in the nucleus of the atom since the creation of the world, now could be released at will.

When World War II was ended, the impulse to test the new power was irresistible. There was profound curiosity about the revolutionary nature of the new force. There was a perplexed and fearful realization that the release of energy would have to be guarded and controlled. There was the knowledge that nuclear fission produced a miscellany of radioactive products presenting unexplored possibilities of hazard. The word “fallout” was coined to describe the deposition on the earth of radioactive debris from nuclear explosions.

Joint Task Force One

The first peacetime nuclear tests, conducted at Bikini in 1946 in a military-scientific exercise designated Operation Crossroads, were designed to assess the effects of nuclear weapons on naval vessels. The test organization, Joint Task Force One, an adaptation of the wartime joint task force combat concept, was a massive waterborne force including 42,000 members of the armed services, civilian scientists, consultants, and observers.

The Bikini Lagoon before testing.

Bikini Atoll was selected for the tests because, among other things, it was remote from heavily populated areas, it offered a protected anchorage, and it had the relatively stable and predictable meteorological and oceanographic conditions considered essential to operations in which the unknowns loomed so large. Three test detonations originally were projected; two ultimately were carried out. The first, Test Able, was an airdrop of an atomic bomb on July 1, 1946, over a test fleet of 70 ships anchored in Bikini Lagoon. The second, Test Baker, was the detonation on July 25 of an atomic device suspended in the lagoon 90 feet below a small target vessel.

Scientific Interests

Although Crossroads was a military program, the mobilization of scientific interests was in many ways of historic proportions. For months before the explosions, oceanographers studied the waters and the structure of the mid-Pacific basin and meteorologists the winds and upper airs. Geologists, zoologists, botanists, and other specialists examined the atoll in detail. Bikini became, as it remains to this day, one of the most thoroughly familiar ocean structures in the world.