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Octahedral Research Satellite Series

Octahedral Research Satellite Series

The ORS 3 (ERS-17) spacecraft.

The ORS 3 (ERS-17) spacecraft. (Credit: USAF)

The Octahedral Research Satellites were a series of satellites launched by the U. S. Airforce in the 1960s. Each was shaped as a regular octahedron measuring 28 cm on a side. These were also part of the Environmental Research Satellite series, so they have ORS and ERS designations. ORS 3 (ERS-17) and ORS 4 (ERS-18) each included X-ray and gamma-ray detectors which perfomred cosmic high energy observations.

Lifetime: September 1964 (first launch, OGO-1) - March 1972 (last satellite, OSO-6, ceases operation)

Country (primary): United States


Lifetime: July 1965 - Novmeber 1965

Primary Science

The primary science of ORS 3 was to perform trapped radiation measurements to correlate with Vela data. In addition, ORS 3 studied cosmic rays and detected solar and galacitc X-rays and gamma rays.

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Lifetime: April 1967 - June 1968

Primary Science

The primary science objectives of ORS 4 were to measure the cosmic gamma-ray spectrum between 0.25 and 6 MeV, monitor the solar X-ray flux, obtain a background measurement for a prototype space nuclear detonation detector, and measure charged particles within the magnetosphere.

Science Highlights

  • Measured the diffuse cosmic gamma-ray background.

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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

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