Tags: Artificialsatellite, Satellite.
Explorer 11 (also known as S15) was an American Earth-orbital satellite that carried the first space-borne gamma-ray telescope. This was the earliest beginning of space gamma-ray astronomy. Launched on April 27 1961 by a Juno II rocket the satellite returned data until November 17 when power supply problems ended the science mission. During the spacecraft’s seven-month lifespan it detected twenty-two events from gamma-rays and approximately 22000 events from cosmic radiation.
