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Explorer 11

Explorer 11

An artist's impression of Explorer 11 in flight

An artist's impression of the Explorer 11 satellite in flight. (Credit: NASA)

Lifetime: April 1961 - November 1961

Portion(s) of spectrum studied: gamma ray

Country (primary): United States

Primary Science

Explorer 11 was the first space-bourne gamma-ray telescope.

Science Highlights

  • Detection of 22 gamma-ray events.


  • Gamma-ray detector sensitive to gamma rays with energy above 50 MeV

Links to more information


A service of the High Energy Astrophysics Science Archive Research Center (HEASARC), Dr. Alan Smale (Director), within the Astrophysics Science Division (ASD) at NASA/GSFC

NASA Logo, National Aeronautics and Space Administration