Operation Hardtack I High Altitude Nuclear Tests 1958 US Air Force Lookout Mountain Laboratory

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Originally a public domain film from the National Archives, slightly cropped to remove uneven edges, with the aspect ratio corrected, and one-pass brightness-contrast-color correction & mild video noise reduction applied.

The soundtrack was also processed with volume normalization, noise reduction, clipping reduction, and/or equalization (the resulting sound, though not perfect, is far less noisy than the original).

https://en.wikipedia.org/wiki/Operation_Hardtack_I

Wikipedia license: http://creativecommons.org/licenses/by-sa/3.0/

Operation Hardtack I was a series of 35 nuclear tests conducted by the United States from April 28 to August 18 in 1958 at the Pacific Proving Grounds. At the time of testing, the Operation Hardtack I test series included more nuclear detonations than the total of all prior nuclear explosions in the Pacific Ocean. These tests followed the Project 58/58A series, which occurred from 1957 December 6 to 1958, March 14, and preceded the Operation Argus series, which took place in 1958 from August 27 to September 6.

Operation Hardtack I was directed by Joint Task Force 7 (JTF 7). JTF-7 was a collaboration between the military and many civilians, but was structured like a military organization. Its 19,100 personnel were composed of members of the US military, federal civilian employees, as well as workers affiliated with the Department of Defense (DOD) and the Atomic Energy Commission (AEC).

There were three main research directions. The first was the development of new types of nuclear weapons... The final avenue of study was to analyze high-altitude nuclear tests to refine the detection of high-altitude nuclear tests and investigate defensive practices for combatting ballistic missiles. This research direction was composed of three individual tests and were the first high-altitude tests. The individual tests in the series were Orange, Teak, and Yucca. Orange and Teak were known collectively as Operation Newsreel and were rocket boosted. Yucca reached its altitude utilizing balloons...

Operation Hardtack I contained three high-altitude tests that were designed to study many effects that a nuclear explosion would have on materials and electronic systems. They were also used to test the energy of the explosion and what forms of energy they would produce. Yucca was the name of the first high-altitude test and it was performed near the Enewetak Atoll in the Marshall Islands. The other two high-altitude tests, Orange and Teak, were performed near the Johnston Atoll in the South Pacific Ocean about 1,300 kilometers southwest of the Hawaiian Islands...

Yucca was the first high-altitude test performed during Operation Hardtack I and was detonated on April 28, 1958. It was lifted by a balloon to an altitude of 86,000 feet (26.2 km) and had a yield of 1.7 kilotons. To achieve the altitude needed, the device was attached to a large helium-filled balloon which carried it to the detonation altitude...

The Teak test was launched from Johnston Island on July 31, 1958 and carried a payload of 3.8 megatons. Teak was the second high-altitude test after the success of Yucca. Instead of a balloon, the warhead for the Teak test would be carried by a Redstone missile; a modified Redstone missile had been used to launch Explorer I in January of the same year. Other nuclear weapons had been tested using the Redstone missile, but until this time the highest payload to have been detonated was 3 kilotons during Operation Teapot. Teak would be the first high-altitude test to have a payload in the megaton range. The test was scheduled to take place from the Bikini Atoll. Due to the fact that the payloads of Teak and Orange were much larger than previous high-altitude shots, the test was moved to Johnston Island as to protect nearby native islanders from any retinal damage...

At 11:47 PM on July 31 Teak was launched; after 3 minutes it was detonated. Due to programming issues, the warhead detonated directly above Johnston Island. At time of detonation the rocket had flown to an altitude of 76.2 kilometers (47.3 mi). The explosion could be seen from Hawaii 1,297 kilometers (806 mi) away and was said to be visible for almost half an hour. After the explosion, high frequency long distance communication was interrupted across the Pacific. Due to this communication failure Johnston Island was unable to contact their superiors to advise of the test results until about eight hours after the detonation...

Orange was launched twelve days after Teak on August 11, 1958. Orange, like Teak, was launched using a Redstone Missile and had a yield of 3.8 megatons...