A U.S. spy pilot watched a vast wall of light race out of Soviet territory during a missile mission. A U.S. Air Force pilot reported seeing a vast wall of light sweep across the sky during two Cold War missions monitoring Soviet SS-20 Saber missile launches in 1988. The phenomenon later became known as the “Dome of Light,” but Air Force investigators never established its origin or purpose. The aircraft was monitoring an SS-20 launch toward the Kura Test Range at Klyuchi as part of U.S. efforts to observe Soviet missile activity. Material from 1988 also linked the term “Dome of Light” with possible efforts to conceal or protect a missile launch.