Secret Chronicles: The crazy experiment over the Marshall Islands where a plane flew through the epicenter of a nuclear mushroom

In 1946, the United States conducted tests at Bikini Atoll, Marshall Islands. Codenamed Operation Crossroads, two nuclear explosions, Able and Baker, set off a long chain of experiments that devastated the Pacific ecosystem. To measure the parameters of the explosion, the US military sent aircraft directly to the center of the nuclear mushroom, and representatives from different countries, including the Soviet Union, observed what was happening from the ground.

In 1945-46, the United States was looking for a suitable site for nuclear testing, and the choice fell on the Marshall Islands: they were under the control of the States, were sparsely populated and had a rather mild climate. A few natives were taken to another island, albeit with worse conditions, and warships and aircraft, equipment for surveys and measurements, as well as thousands of laboratory animals were brought to Bikini Atoll.

In the summer of 1946, a series of two nuclear explosions with a capacity of 23 kilotons each thundered: the Able charge was blown up at a height of 158 m on July 1st, and the Baker at a depth of 27 m under water on July 25th. Three explosions were originally planned, but the last had to be abandoned because after the Baker, the US military was unable to deactivate the ships. Subsequently, this underwater explosion was called the world’s first nuclear disaster, as it led to a serious contamination of the area.

The operation “Crossroads” involved 242 warships and 156 aircraft, which housed special equipment. “Able” was dropped from a B-29 bomber, after the detonation of the charge, a massive nuclear mushroom formed, right at the epicenter of which 8 B-17 bombers were sent. On board were automatic photographic equipment, collections of air samples and radiation detectors.

The planes flew over a zone with a high level of radiation, including the nuclear mushroom itself. At the same time, there was no crew inside: for the pilots, such a flight would be the last. Air vehicles were controlled by radio-controlled autopilots. The pilots were in other aircraft flying at a safe distance, and controlled the bombers remotely.

The operation was successful: the cameras captured 50,000 photographs and 457 km of film. Those who were on board the aircraft noted that they felt “mild symptoms of a concussion.”

Effect and aftermath of the explosions

More than 100 people from different countries attended as observers. The US Navy spent a long time in strict secrecy about its preparations for this operation, codenamed “Crossroads”, but just before the start of the tests, scientific observers from each country – members of the UN Security Council were invited to them. 

The invited public was not particularly happy with the tests. The first bomb was off course by 649 m, which caused the damage to be much weaker than many expected. Of the entire fleet, only 5 ships sank.

The second charge, underwater, brought more destruction.

The power and heat of the world’s fifth nuclear bomb foamed the Bikini Lagoon, turning it into a seething cauldron of flame, smoke and steam, scattered the ships like toy boats, but could not sink most of the large ships lined up in battle formation in the “circle of death” next to the bomb, according to a report by journalist Don Whitehead.

However, the most terrible consequences of the Baker tests are not physical destruction, but colossal amounts of radiation. The radioactive decay products infected the entire fleet and, mixed with water and sand, spread to virtually the entire atoll. The US crew failed to deactivate the ships.

Subsequently, the Marshall Islands and, in particular, the Bikini Atoll survived several dozen more trials, which finally destroyed the local ecosystem. The evicted Bikinians cannot return home to this day, and the extent of the infections is not known for certain. Attempts to conduct an independent study were made in 2015-2018.

“Until now, there have been no independent investigations into radioactive contamination and its consequences. All the previous … years on the Marshalls, if any study of water and soil was carried out for the background radiation, then this was done exclusively by the military,” quotes El País Monica Ruko, Deputy Director of the Center for Nuclear Research at Columbia University.

In a predictable way, scientists recorded a significantly increased radiation background – in some cases even exceeding the figures for Chernobyl and Fukushima.