In late August and early September of 1958, U.S. Navy Task Force 88, consisting of nine ships and approximately 4,500 men, secretly conducted three high-altitude nuclear tests in the South Atlantic. The code name of the operation was ARGUS. In each of these tests, the task force launched from the missile trials ship, USS Norton Sound (AVM-1), a specially modified X-17a three-stage ballistic missile carrying a low-yield nuclear warhead, which was detonated high in the Earth's upper atmosphere. Upon completion of these launchings on September 6, the task force departed the operating area for Rio de Janeiro, Brazil, and thence to home ports in the United States. This report details Department of Defense personnel participation in these tests, with an emphasis on radiological safety.
The ARGUS shots were conducted to test the Christofilos theory, which argued that high-altitude nuclear detonations would create a radiation belt in the upper regions of the Earth's atmosphere. It was postulated that these belts of radiation (primarily high-energy electrons) might cause degradation of radio and radar transmissions, damage or destruction of the arming mechanisms of ICBM warheads, and endangerment of crews in orbiting space vehicles that might enter the belt.