In October of 1963 the US Air Force launched the first in a series of satellites inspired by a recently signed nuclear test ban treaty . Signatories of this treaty agreed not to test nuclear devices in the atmosphere or in space. A Vela satellite is pictured above in an artist's conception, keeping watch over the Earth. The high energy radiation sensors onboard the Velas did not detect any clandestine nuclear explosions . The mysterious origin of these brief, intense flashes of gamma rays is one of the most hotly debated topics in modern astrophysics.
Specific rights apply.