September 22, 1979 - The Vela Incident

On this day in engineering history, a United States Vela satellite detected a double flash of light in the Indian Ocean between Bouvet Island and the Prince Edward Islands. The satellite's primary mission was to monitor Earth's atmosphere and space for nuclear explosions in accordance with the 1963 Partial Test Ban Treaty, an international agreement that prohibited the detonation of nuclear weapons except underground.

An ad hoc panel later found that the cause of the September 22, 1979 incident was a meteoroid hitting the satellite. Although the panel cited a discrepancy in bhangmeter readings as evidence, others who examined satellite data concluded that the double flash was a nuclear detonation. These parties included government contractors, national laboratories, and the Defense Intelligence Agency (DIA) - a part of the U.S. Department of Defense (DoD).

The Partial Test Ban Treaty of 1963 was signed by the world's three nuclear-capable countries (the U.S., U.K. and U.S.S.R.) to limit how often, when, and where these powers could test nuclear weapons. To monitor treaty compliance and help halt nuclear proliferation, the United States launched Project Vela (the word "vela" means vigil in Spanish). .U.S. efforts were divided into three parts: ground (and subterranean), atmospheric, and space/orbit detonations.

Proving a Test Was Harder Than Envisioned – Limitations in Technology

In addition to analyzing data from the Vela satellite, the United States used other methods to determine if the Vela Incident was a nuclear weapons test. Attempts to collect samples of radioactive fallout were unsuccessful, however. First, there was the problem of reaching the remote Indian Ocean site quickly enough. Second, there were technological considerations.

Those who believe the Vela Incident wasn't a nuclear test cite the age of the satellite, which was already two years past its design retirement date. If the satellite's sensors were no longer fully functional, its readings were probably inaccurate. By design, the sensors on these satellites would detect a nuclear test through a light emission variance (a short, initial flash followed by a second, more prolonged flash).

Assigning Responsibility

Although no one has ever claimed responsibility for the Vela Incident of 1979, there have been a number of theories about the source of the nuclear test. Such speculation has always been a hotter question than whether it was a test in the first place, given the state of the Cold War and other geopolitical problems facing the Carter Administration in 1979.

The three most common theories about the origins of a nuclear detonation are that the Vela Incident was a South African test, an Israeli test, or a joint South African-Israeli test.

Project Phoenix?

Given the geographic location of the Vela Incident, a South African connection seems plausible. That Israel would cooperate with the apartheid regime seems less so. Evidence discovered since the end of South Africa's race-based regime casts new light on the mysterious double-flash, however.

At the time, both Israel and South Africa had nuclear ambitions and capabilities. Accordingly, Israel allegedly assisted South African in developing the delivery system (more than the device itself). A 2008 publication, The Nuclear Express: A Political History of the Bomb and its Proliferation by Thomas C. Reed and Danny B. Stillman add further credence to this possibility.

Thirty years later, details of the Vela Incident remain hidden behind politics, espionage, and government secrecy (even government systems that no longer exist). According to those who have come forward, however, the event was a nuclear test by Israel and South Africa, and possibly dubbed Project Phoenix.

Resources:

http://nuclearweaponarchive.org/Safrica/Vela.html

http://en.wikipedia.org/wiki/Vela_Incident

http://en.wikipedia.org/wiki/Vela_(satellite)

http://en.wikipedia.org/wiki/Project_Vela

http://en.wikipedia.org/wiki/Partial_Test_Ban_Treaty