The Vela Incident: Did an American satellite detect a secret nuclear test in 1979?

It began with an unusual flash detected off the coast of South Africa by an aging American satellite — and to this day, debate continues over whether this odd Cold War event involved an illicit atmospheric nuclear test.The strange story of the "South Atlantic Flash," better known as the Vela Incident, began on Sept. 22, 1979. At that time, Vela 6911, a satellite in a constellation developed by the United States for the specific purpose of detecting nuclear detonations, observed something t