A history of gamma-ray satellites
Browse a list of key satellites from the brief history of orbiting gamma-ray observatories.
Long before they could detect gamma rays, scientists suspected this type of radiation was produced throughout the universe. To identify these emissions, Earth-bound detectors would have to be placed outside our atmosphere, which typically absorbs gamma rays. In 1961, the Explorer XI satellite carried the first gamma-ray telescope into Earth orbit, which gathered fewer than 100 cosmic gamma-ray photons. While astronomers use Earth-based observatories to identify gamma ray bursts, they still utili...