Gamma was a Soviet-French gamma-ray telescope launched on 11 July 1990 into an orbit 375 kilometres above Earth. It operated for about two years and carried three telescopes that could point at the same target. The main instrument, Gamma-1, was designed to detect gamma rays from 50 MeV to 6 GeV, while Disk-M and Pulsar X-2 covered lower energy ranges. The mission studied sources including the Vela Pulsar, the Galactic Center, Cygnus X-1, Hercules X-1 and the Crab Nebula, as well as the Sun during peak solar activity. Conceived in 1965 as part of a proposed Soviet space station, Gamma was redesigned as a free-flying satellite after station plans changed. Its launch, initially planned for 1984, came six years later.