Boom

A nuclear explosion as seen from space in 1962. [Link]

Operation Fishbowl.

The Operation Fishbowl nuclear tests were originally planned to be completed during the first half of 1962 with three tests named Bluegill, Starfish and Urraca.^[1]

The first test attempt was delayed until June. Planning for Operation Fishbowl, as well as many other nuclear tests in the region, was begun rapidly in response to the sudden Soviet announcement on 30 August 1961 that they were ending a three year moratorium on nuclear testing.^[2] The rapid planning of very complex operations necessitated many changes as the project progressed.

Urraca was to be a low yield test at very high altitude. The proposed Urraca test was always controversial, especially after the damage caused to satellites by theStarfish 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 25 July 1962, as described below.

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 theUnited States Atomic Energy Commission, opposed doing any high-altitude tests at locations that had been used for earlier Pacific nuclear tests. His opposition was because of 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.^[3] In order 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.

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 were 5:

Successful High-Altitude Nuclear Tests of Operation Fishbowl^[4][5]

Test name	Date (UTC)	Time (UTC)	Yield (approximate)	Altitude (km)	Longitude, °N	Latitude, °W
Starfish Prime	9 July 1962	09:00:09	1.4 megatons	400.1	16° 28'   6.3"	169° 37'  48.3"
Checkmate	20 October 1962	08:30:00	Low kiloton	147.3	16°  4'  20.6"	169° 36'  35.9"
Bluegill Triple Prime	26 October 1962	09:59:48	Submegaton	48.32	16° 24'  57.0"	169° 36'  11.2"
Kingfish	1 November 1962	12:10:06	Submegaton	97.24	16°  6'  48.6"	169° 40'  56.0"
Tightrope	4 November 1962	07:30:00	Low kiloton	21.03	16° 42'  26.7"	169° 32'  32.7"

According to the United States government reporting system, in the above table: "Submegaton" means a nuclear weapon yield of less than one megaton and greater than 200 kilotons. "Low kiloton" means a nuclear weapon yield of less than 20 kilotons.^[4] Probable weapon yields are discussed further in the text below describing the particular test. Detonation times are Coordinated Universal Time in the format hours:minutes:seconds