Hardtack Teak

Hardtack Teak
Information
Country	United States
Test series	Operation Hardtack I
Test site	Johnston Island
Date	August 1, 1958
Test type	Exoatmospheric
Yield	3.8 Mt

HARDTACK-Teak was an high altitude nuclear weapon test performed during Operation Hardtack I. It was launched from Johnston Island on a Redstone missile. On 1 August 1958, the 3.8 Mt shot detonated at an altitude of 76.8 km.

Along with HARDTACK-Orange it was one of the two largest high-altitude nuclear explosions.

The 3.8 megaton detonation was planned to occur at an altitude of 250,000 feet approximately six miles south of Johnston Island. However, due to a programming failure it burst directly over the island at the desired elevation making the island the effective ground-zero. This brought the explosion 2,000 feet (approximately 2/5ths of a mile) nearer than intended to the launch site control and analysis crews.

The Teak test was originally planned to be launched from Bikini Atoll, but Lewis Strauss, chairman of the United States Atomic Energy Commission opposed the test because of fears that the flash from the nighttime detonation might blind Islanders who were living on nearby atolls. He finally agreed to approve the high-altitude test on the condition that the launch point be moved from Bikini Atoll to the more remote site at Johnston Island.

According to the United States Defense Nuclear Agency report (DNA6038F) on Operation Hardtack I:

Teak caused communications impairment over a widespread area in the Pacific basin. This was due to the injection of a large quantity of fission debris into the ionosphere. The debris prevented normal ionospheric reflection of high-frequency (HF) radio waves back towards Earth, which disrupted most long-distance HF radio communications. The nuclear detonation occurred at 10:50 UTC on 1 August 1958 (which was 11:50 p.m., Johnston Island local time, on 31 July 1958).

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