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The HEAO-3 Satellite

photo of HEAO-3 in the clean room
Credit: NASA

The HEAO-3 satellite, like HEAO-1, was a survey mission operating in the hard X-ray and gamma-ray band. The High Resolution Gamma-Ray Spectrometer Experiment, built by the Jet Propulsion Laboratory, was the largest germanium spectrometer placed in orbit at that time. The cryogen for the Ge detectors was exhausted on day 154 of 1980, effectively ending the mission.

Mission Characteristics

* Lifetime: 20 September 1979 - 29 May 1981
* Energy Range: 50 keV - 10 MeV
* Payload:
  • High Resolution Gamma Ray Spectrometer (HRGRS): 50 keV - 10 MeV, FOV 30°, effective area 75 cm2 at 100 keV
  • Heavy Nuclei Experiment
  • Cosmic Ray Isotope Experiment
* Science Highlights:
  • Sky survey of gamma-ray narrow-line emission.

* Archive: HEASARC holds the HRGRS data in their native format. Other HEAO-3 data sets are at the NSSDC ( in their native format.

[About HEAO-3] ( [Archive] ( [Gallery] ( [Publications] (

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