Operation Fishbowl was a series of high-altitude nuclear tests in 1962 that were carried out by the United States as a part of the larger Operation Dominic nuclear test program.
Introduction
The Operation Fishbowl nuclear tests were originally to be completed during the first half of 1962 with three tests named Bluegill, Starfish and Urraca.
The first test attempt was delayed until June. Planning for Operation Fishbowl, as well as many other nuclear tests in the region, began rapidly in response to the sudden Soviet announcement on August 30, 1961, that they were ending a three-year moratorium on nuclear testing. The rapid planning of very complex operations necessitated many changes as the project progressed.
All of the tests were to be launched on missiles from Johnston Island in the Pacific Ocean north of the equator. Johnston Island had already been established as a launch site for United States high-altitude nuclear tests, rather than the other locations in the Pacific Proving Grounds. In 1958, Lewis Strauss, then chairman of the United States Atomic Energy Commission, opposed doing any high-altitude tests at locations that had been used for earlier Pacific nuclear tests. His opposition was motivated by fears that the flash from the nighttime high-altitude detonations might blind civilians who were living on nearby islands. Johnston Island was a remote location, more distant from populated areas than other potential test locations.Defense's Nuclear Agency 1947–1997. p. 139. Defense Threat Reduction Agency, 2002 To protect residents of the Hawaiian Islands from flash blindness or permanent retinal injury from the bright nuclear flash, the nuclear missiles of Operation Fishbowl were launched generally toward the southwest of Johnston Island so that the detonations would be farther from Hawaii.
Urraca was to be a test of about 1 megaton yield at very high altitude (above 1000 km).Conrad, Edward E., et al. "Collateral Damage to Satellites from an EMP Attack" Report DTRA-IR-10-22, Defense Threat Reduction Agency. August 2010 (Retrieved January 20, 2014) The proposed Urraca test was always controversial, especially after the damage caused to satellites by the Starfish Prime detonation, as described below. Urraca was finally canceled, and an extensive re-evaluation of the Operation Fishbowl plan was made during an 82-day operations pause after the Bluegill Prime disaster of July 25, 1962, as described below.
A test named Kingfish was added during the early stages of Operation Fishbowl planning. Two low-yield tests, Checkmate and Tightrope, were also added during the project, so the final number of tests in Operation Fishbowl was five. Tightrope was the last atmospheric nuclear test conducted by the United States, as the Limited Test Ban Treaty came into effect shortly thereafter.
Research directions
The United States completed six high-altitude nuclear tests in 1958, but the high-altitude tests of that year raised a number of questions. According to U.S. Government Report ADA955694 on the first successful test of the Fishbowl series, "Previous high-altitude nuclear tests: Teak, Orange, and Yucca, plus the three ARGUS shots were poorly instrumented and hastily executed. Despite thorough studies of the meager data, present models of these bursts are sketchy and tentative. These models are too uncertain to permit extrapolation to other altitudes and yields with any confidence. Thus there is a strong need, not only for better instrumentation, but for further tests covering a range of altitudes and yields."
There were three phenomena in particular that required further investigation: The electromagnetic pulse generated by a high-altitude nuclear explosion appeared to have very significant differences from the electromagnetic pulse generated by nuclear explosions closer to the surface. The auroras associated with high-altitude nuclear explosions, especially the auroras that appeared almost instantaneously far away from the explosion in the opposite hemisphere, were not clearly understood. The nature of the possible radiation belts that were initially generated along the magnetic field lines connecting the areas of the auroral displays were also poorly understood. Areas of blackout of radio communication needed to be understood in much more detail since that information would be critical for military operations during periods of possible nuclear explosions.
The Fishbowl tests were monitored by a large number of surface and aircraft-based stations in the wide area around the planned detonations and also in the region in the southern hemisphere in the Samoan Islands region, which was known in these tests as the southern conjugate region. Johnston Island is in the northern hemisphere, as were all of the planned Operation Fishbowl nuclear detonation locations. It was known from previous high altitude tests, as well as from theoretical work done in the late 1950s, that high-altitude nuclear tests produce a number of unique geophysical phenomena at the opposite end of the magnetic field line of the Earth's magnetic field.
According to the standard reference book on nuclear weapon effects by the United States Department of Defense, "For the high-altitude tests conducted in 1958 and 1962 in the vicinity of Johnston Island, the charged particles entered the atmosphere in the northern hemisphere between Johnston Island and the main Hawaiian Islands, whereas the conjugate region was in the vicinity of the Samoan, Fiji, and Tonga Islands. It is in these areas that auroras were actually observed, in addition to those in the areas of the nuclear explosions."Glasstone, Samuel and Dolan, Philip J., The Effects of Nuclear Weapons. Chapter 2, sections 2.144 and 2.145. United States Department of Defense. 1977.
Beta particles are charged particles (usually with a negative electrical charge) that are released from nuclear explosions. These particles travel in a spiral along the magnetic field lines in the Earth's magnetic field. The nuclear explosions also release heavier debris ions, which also carry an electrical charge, and which also travel in a spiral along the Earth's magnetic field lines.
The Earth's magnetic field lines arc high above the Earth until they reach the magnetic conjugate area in the opposite hemisphere.
According to the DOD nuclear weapon effects reference, "Because the beta particles have high velocities, the beta auroras in the remote (southern) hemisphere appeared within a fraction of a second of those in the hemisphere where the burst had occurred. The debris ions, however, travel more slowly and so the debris aurora in the remote hemisphere, if it is formed, appears at a somewhat later time. The beta auroras are generally most intense at an altitude of 30 to 60 miles, whereas the intensity of the debris auroras is greatest in the 60 to 125 miles range. Remote conjugate beta auroras can occur if the detonation is above 25 miles, whereas debris auroras appear only if the detonation altitude is in excess of some 200 miles."
Some of the charged particles traveling along the Earth's magnetic field lines cause auroras and other geophysical phenomena in the conjugate areas. Other charged particles are reflected back along the magnetic field lines, where they can persist for long periods of time (up to several months or longer), forming artificial radiation belts.Hoerlin, Herman "United States High-Altitude Test Experiences: A Review Emphasizing the Impact on the Environment" Report LA-6405, Los Alamos Scientific Laboratory. October 1976 Retrieved January 12, 2010
According to the Operation Fishbowl planning document of November 1961, "Since much valuable data can be obtained from time and spectrum resolved photography, this dictates that the test be performed at nighttime when auroral photographic conditions are best." As with all U.S. Pacific high-altitude nuclear tests, all of the Operation Fishbowl tests were completed at night. This is in contrast to the high-altitude nuclear tests of the Soviet Project K nuclear tests, which were done over the populated land region of central Kazakhstan, and therefore had to be done during the daytime to avoid eyeburn damage to the population from the very bright flash of high-altitude nuclear explosions (as discussed in the introduction to this article).
First attempts
According to the initial plan of Operation Fishbowl, the nuclear tests were to be Bluegill, Starfish and Urraca, in that order. If a test were to fail, the next attempt of the same test would be of the same name plus the word "prime." If Bluegill failed, the next attempt would be Bluegill Prime, and if Bluegill Prime failed, the next attempt would be Bluegill Double Prime, etc.
Bluegill
The first planned test of Operation Fishbowl was on June 2, 1962, when a nuclear warhead was launched from Johnston Island on a Thor missile just after midnight. Although the Thor missile appeared to be on a normal trajectory, the radar tracking system lost track of the missile. Because of the large number of ships and aircraft in the area, there was no way to predict if the missile was on a safe trajectory, so the range safety officers ordered the missile with its warhead to be destroyed. No nuclear detonation occurred and no data were obtained, but subsequent investigation found that the Thor was actually following the proper flight trajectory.
Starfish
The second planned test of Operation Fishbowl was on June 19, 1962. The launch of a Thor missile with a nuclear warhead occurred just before midnight from Johnston Island. The Thor missile flew a normal trajectory for 59 seconds; then the rocket engine suddenly stopped, and the missile began to break apart. The range safety officer ordered the destruction of the missile and the warhead. The missile was between 30,000 and 35,000 feet (between 9.1 and 10.7 km) in altitude when it was destroyed.
Some of the missile parts fell on Johnston Island, and a large amount of missile debris fell into the ocean in the vicinity of the island. Navy Explosive Ordnance Disposal and Underwater Demolition Team swimmers recovered approximately 250 pieces of the missile assembly during the next two weeks. Some of the debris was contaminated with plutonium. Nonessential personnel had been evacuated from Johnston Island during the test.
Starfish Prime
On July 9, 1962, at 09:00:09 Coordinated Universal Time, which was nine seconds after 10 p.m. on July 8, Johnston Island local time, the Starfish Prime test was successfully detonated at an altitude of . The coordinates of the detonation were 16 degrees, 28 minutes North latitude, 169 degrees, 38 minutes West longitude (30 km, or about 18 mi, southwest of Johnston Island). The actual weapon yield was very close to the design yield, which has been described by various sources at different values in the very narrow range of 1.4 to 1.45 megatons (6.0 PJ).
The Thor missile carrying the Starfish Prime warhead actually reached an apogee (maximum height) of about 1100 km (just over 680 miles), and the warhead was detonated on its downward trajectory when it had fallen to the programmed altitude of . The nuclear warhead detonated at 13 minutes and 41 seconds after liftoff of the Thor missile.Dyal, P., Air Force Weapons Laboratory. Report ADA995428. "Operation Dominic. Fish Bowl Series. Debris Expansion Experiment." December 10, 1965. p. 15. Retrieved July 17, 2010