Hardtack Teak
Encyclopedia
HARDTACK-Teak was an exoatmospheric 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. 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 wave
s back towards Earth
, which disrupted most long-distance HF radio
communication
s. The nuclear detonation occurred at 1050 UTC
on 1 August 1958 (which was 11:50 p.m., Johnston Island local time, on 31 July 1958).
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 book Defense's Nuclear Agency 1947–1997, when the Teak detonation occurred:
Operation Hardtack I
Operation Hardtack I was a series of 35 nuclear tests conducted by the United States in 1958 in the Pacific Ocean.Operation Newsreel was a series of three high-altitude nuclear tests conducted as part of Hardtack I. The individual tests in the series were Orange, Teak and Yucca.-Test Blasts:-...
. It was launched from Johnston Island
Johnston Atoll
Johnston Atoll is a atoll in the North Pacific Ocean about west of Hawaii. There are four islands located on the coral reef platform, two natural islands, Johnston Island and Sand Island, which have been expanded by coral dredging, as well as North Island and East Island , an additional two...
on a Redstone missile. On 1 August 1958, the 3.8 Mt
TNT equivalent
TNT equivalent is a method of quantifying the energy released in explosions. The ton of TNT is a unit of energy equal to 4.184 gigajoules, which is approximately the amount of energy released in the detonation of one ton of TNT...
shot detonated at an altitude
Altitude
Altitude or height is defined based on the context in which it is used . As a general definition, altitude is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The reference datum also often varies according to the context...
of 76.8 km. Teak caused communications impairment over a widespread area in the Pacific basin. This was due to the injection of a large quantity of fission
Nuclear fission
In nuclear physics and nuclear chemistry, nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts , often producing free neutrons and photons , and releasing a tremendous amount of energy...
debris into the ionosphere
Ionosphere
The ionosphere is a part of the upper atmosphere, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere...
. The debris prevented normal ionospheric reflection of high-frequency (HF) radio wave
Radio Wave
Radio Wave may refer to:*Radio frequency*Radio Wave 96.5, a radio station in Blackpool, UK...
s back towards Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
, which disrupted most long-distance HF radio
Radio
Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...
communication
Communication
Communication is the activity of conveying meaningful information. Communication requires a sender, a message, and an intended recipient, although the receiver need not be present or aware of the sender's intent to communicate at the time of communication; thus communication can occur across vast...
s. The nuclear detonation occurred at 1050 UTC
Coordinated Universal Time
Coordinated Universal Time is the primary time standard by which the world regulates clocks and time. It is one of several closely related successors to Greenwich Mean Time. Computer servers, online services and other entities that rely on having a universally accepted time use UTC for that purpose...
on 1 August 1958 (which was 11:50 p.m., Johnston Island local time, on 31 July 1958).
Along with HARDTACK-Orange it was one of the two largest high-altitude nuclear explosions.
The 3.8 megaton
TNT equivalent
TNT equivalent is a method of quantifying the energy released in explosions. The ton of TNT is a unit of energy equal to 4.184 gigajoules, which is approximately the amount of energy released in the detonation of one ton of TNT...
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
Bikini Atoll
Bikini Atoll is an atoll, listed as a World Heritage Site, in the Micronesian Islands of the Pacific Ocean, part of Republic of the Marshall Islands....
, but Lewis Strauss, chairman of the United States Atomic Energy Commission
United States Atomic Energy Commission
The United States Atomic Energy Commission was an agency of the United States government established after World War II by Congress to foster and control the peace time development of atomic science and technology. President Harry S...
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 book Defense's Nuclear Agency 1947–1997, when the Teak detonation occurred:
- The Apia Observatory in Western Samoa approximately 2,000 miles to the south described the ". . . violent magnetic disturbance," which heralded ". . . the most brilliant manifestation of the Aurora Australis [Southern Lights] ever seen in Samoa." The resulting persistent ionization of the low-density atmosphere cut high frequency radio communications with New Zealand for six hours.
- In Hawaii, where there had been no announcement of the test, the TEAK fireball turned from light yellow to dark yellow to orange to red. "The red spread in a semi-circular manner until it seemed to engulf a large part of the horizon," one resident told the Honolulu Star-Bulletin. The red glow remained clearly visible in the southwestern sky for half an hour. In Honolulu, military and civilian air traffic communications were interrupted for several hours. At the AFSWP’s Armed Forces Special Weapons ProjectArmed Forces Special Weapons ProjectThe Armed Forces Special Weapons Project was a United States military agency responsible for those aspects of nuclear weapons remaining under the military after the the Manhattan Project was succeeded by the Atomic Energy Commission on 1 January 1947...
offices in the Pentagon, Admiral Parker grew concerned for the personnel on Johnston Island as hour after hour passed with no word regarding the test. Finally, some eight hours after TEAK had occurred, the word that all was well came from Luedecke, the commander of Joint Task Force 7 and soon to be General Manager of the AEC. The communications blackout worried others as well. Later AFSWP learned that one of the first radio messages received at Johnston Island once communications was restored was: "Are you still there?"