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The Vela-5B Satellite

artist concept of Vela 5B
Credit: Los Alamos National Laboratory

Vela-5B was part of a classified series of US Vela satellites.The program was run jointly by the Advanced Research Projects of the U.S. Department of Defense and the U.S. Atomic Energy Commission, managed by the U.S. Air Force. They were not intended primarily for astronomical studies but did provide much useful celestial data. The Vela-5A and 5B satellites were launched in 1969 and Vela-6A and 6B in 1970 and they operated in spinning mode. Each operated for about a year except Vela-5B which provided data until mid 1979.

Mission Characteristics

* Lifetime: 23 May 1969 - 19 June 1979
* Energy Range: 3-750 keV
* Payload:
  • A Scintillation X-ray detector (All-Sky Monitor; ASM)
    3-12 keV ~26 cm2, ~6.1° x 6.1 ° FOV (FWHM)
  • 6 Gamma Ray detectors
    150-750 keV Total volume ~60 cm3 of CsI
* Science Highlights:
  • Long lifetime allowed for study of long-term variability of X-ray binaries and X-ray transients.
  • One of the first satellites to detect gamma-ray bursts
  • Co-discovered (with ANS) X-ray bursts.
* Archive: Lightcurves and Raw data from the ASM

[About Vela-5B] ( [Archive] ( [Gallery] ( [Publications] (

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