Operation Argus was a series of secret United States tests conducted from August 27 to September 9, 1958, over the South Atlantic Ocean. These tests involved small nuclear weapons and missile launches, and were carried out by the Defense Nuclear Agency.

The purpose of the tests was to study the Christofilos effect, a theory that suggested using a few small nuclear bombs exploded high above the South Pacific could create a large area of electrons over the United States. This area might have caused problems with the electronic systems of Soviet nuclear warheads as they fell, and could also have prevented Soviet radars from working properly, making it harder for Soviet anti-missile systems to detect and attack U.S. counterstrikes.

The tests showed that the Christofilos effect did occur, but the electron area disappeared too quickly to be useful. Papers about the tests were published the following year, describing the events as scientific experiments.

Objectives

The tests were suggested by Nicholas Christofilos in a paper that was not published. At the time, the paper was written by the Livermore branch of the Lawrence Radiation Laboratory, which is now called the Lawrence Livermore National Laboratory. The tests aimed to confirm the Christofilos effect, which stated that high-altitude nuclear explosions could create radiation belts in the upper atmosphere. These belts would act like the Van Allen radiation belts. "Such radiation belts could be used in war, possibly by weakening radio and radar signals, damaging or destroying the parts of intercontinental ballistic missile warheads that control their activation, and putting the crews of spacecraft in danger if they entered the belt." Before the Argus tests, the Hardtack Teak experiment showed that nuclear explosions could disrupt radio communications, but this was not caused by radiation belts.

The Argus tests were carried out quickly because rules banning atmospheric and exoatmospheric nuclear testing were set to begin in October 1958. Because of this, the tests were completed within six months of being planned (usually, such tests took one to two years). Since nuclear testing at this time may have broken the rules, the military used equipment from the International Geophysical Year to hide the nuclear tests.

Originally, the project was called Hardtack-Argus, and later Floral. For security reasons, both names were no longer used, and the project was renamed Argus.

Funding for the project came from the Armed Forces Special Weapons Project (AFSWP), which is now known as the Defense Threat Reduction Agency (DTRA). The total money given for the project was $9,023,000.

Task Force 88

The United States Navy Task Force 88 (TF-88) was created on April 28, 1958. TF-88 was formed only to carry out Operation Argus. After the operation ended, the task force was disbanded, and its records were separated. Some of these records were destroyed or lost over time. Missing documents included film recordings that measured radiation levels during the Argus tests. This has caused problems because many people who worked on TF-88 later reported cases of leukemia to the Veterans Administration. Because of this, it has been hard to determine how much radiation the participants were exposed to.

The USS Norton Sound (AVM-1) was a United States Navy guided missile ship used for launching missiles. It also trained crews involved in testing. The X-17A missiles used in the test were unfamiliar to the testers. Exercises such as assembling and repairing dummy missiles were done on the Norton Sound. It also carried a 27-MHz COZI radar operated by the Air Force Cambridge Research Center to monitor the effects of the tests. The ship launched three low-yield nuclear warheads into the high atmosphere. Its commanding officer, Captain Arthur R. Gralla, led TF-88. Gralla later received the Legion of Merit for quickly completing the tests.

The USS Albemarle, which had just finished repairs, was not included in the TF-88 order. It traveled to the Atlantic Ocean, supposedly for a shakedown cruise. It also had a COZI radar and other equipment to detect man-made ionization. This included International Geophysical Year (IGY) radiometers, receivers, radar, and optical tools. After adding the IGY equipment, the ship sailed near the Azores to record data at the geomagnetic conjugate point of the South Atlantic test site, while the rest of TF-88 went to the South Atlantic for the tests.

The USS Tarawa was the overall command for the operation, with its commander serving as the Task Group Commander. It carried an Air Force MSQ-1A radar and communication system for tracking missiles. It also housed VS-32 aircraft for search and security operations, as well as scientific measurement, photography, and observation missions for each test. HS-5 was also aboard and transported personnel and cargo within the task force.

The USS Warrington, along with Bearss, Hammerberg, and Courtney, monitored weather conditions 250 nautical miles west of the task force. It also provided air protection for Tarawa during flight operations and performed standard destroyer duties, such as surface security and search and rescue. Warrington also carried equipment for launching Loki Dart sounding rockets.

The USS Neosho refueled ships in the task force during the operation. It was also equipped with Air Force MSQ-1A radar and communication vehicles. Neosho served as the flagship for TG 88.3, the Mobile Logistics Group, which included Neosho, USS Salamonie (AO-26), and assigned destroyers.

The USS Salamonie returned to the United States after arriving at TF-88 and did not take part in any tests.

Satellite tracking

Two satellite launches were tried to gather data from high-altitude tests. Explorer 4 was successfully sent into orbit on July 26 using a Juno I missile from Cape Canaveral. The satellite had enough power to work for sixty days, which was enough time to track and measure ARGUS. Explorer 5 had a failed launch on August 24.

Many tracking systems and organizations helped monitor the satellites and missiles. These included the Naval Research Laboratory, the Army Signal Research and Development Laboratory, the Smithsonian Astrophysical Laboratory, the Army Map Service, the Naval Ordnance Test Station, and the Ballistic Research Laboratory. Ground tracking stations from the Aleutian Islands to the Azores, operated by academic, industrial, and military groups, also helped track the missiles.

Preparation

To prepare for the launch of the ARGUS missiles, many tests and preparations were completed. As the east coast units of TF 88 traveled to the South Atlantic, they practiced countdowns, launches, and missile-tracking procedures using Loki/Dart high-flying rockets designed to defend against aircraft, launched from the USS Warrington. Fourteen Loki rocket launches took place between August 12 and August 22. These tests were conducted to evaluate equipment and procedures, and to train personnel for specific roles. Some of these roles included placing ships in specific locations, using radar systems on the USS Neosho and the USS Tarawa to track missiles, managing communications, positioning sky-camera S2F aircraft, and operating area surveillance S2F aircraft.

Tests

In 1958, the U.S. Navy ship USS Norton Sound launched three modified X-17A missiles with nuclear warheads into the upper atmosphere about 1,800 kilometers southwest of Cape Town, South Africa. These tests took place at a high altitude to avoid exposing people to harmful radiation. The location was chosen because the South Atlantic Anomaly causes the Van Allen radiation belt to be closer to Earth’s surface there. Safety measures were carefully planned by the task force commander and his team to protect all personnel involved.

Scientists and other organizations worldwide used satellites, rockets, planes, and ground stations to measure the effects of the tests. The Argus explosions created artificial electron belts in the atmosphere from the beta decay of nuclear materials. These belts lasted for weeks and disrupted radio and radar signals, damaged missile systems, and posed risks to astronauts. The tests confirmed a theory called the Christofilos effect, which predicted that nuclear explosions in the upper atmosphere would create electron shells from radiation and ionized materials.

The tests were first reported by The New York Times on March 19, 1959, as the “greatest scientific experiment ever conducted.” This report caused controversy because many scientists were unaware of artificial particles in Earth’s atmosphere. Around 4,500 people and nine ships participated in the operation. After the tests, the task force returned to the United States through Rio de Janeiro, Brazil.

The official announcement of the tests came the following year, but full details were not made public until April 30, 1982.