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Vela 5B



Vela 5B was one of two spin-stabilized, polyhedral satellites that comprised the fifth launch in the Vela program. The orbits of the two satellites on each launch were basically circular at about 17 earth radii, inclined at 60 deg to the ecliptic, and spaced 180 deg apart, thus providing a capability of monitoring opposite sides of the earth. The objectives of the satellites were (1) to study solar and cosmic X rays, extreme ultraviolet radiation (EUV), solar protons, solar wind, and neutrons, (2) to carry out research and development on methods of detecting nuclear explosions by means of satellite-borne instrumentation, and (3) to provide solar flare data in support of manned space missions. Vela 5B, an improved version of the earlier Vela series satellites, had better command capabilities, increased data storage, improved power requirements, better thermal control of optical sensors, and greater experimentation weight. Power supplies of 120 W were provided by 22,500 solar cells mounted on 24 of the spacecraft's 26 faces. A rotation rate of 78 rpm during transfer orbits and 1 rpm after final orbit insertion maintained nominal attitude control. Eight whip antennas and four stub antenna arrays at opposite ends of the spacecraft structure were used for ground command and telemetry.

Alternate Names

  • 03955
  • Vela 5B (USAF)
  • Vela 10 (TRW)
  • Vela5B

Facts in Brief

Launch Date: 1969-05-23
Launch Vehicle: Titan III-C
Launch Site: Vandenberg AFB, United States
Mass: 259 kg

Funding Agency

  • Department of Defense-Department of the Air Force (United States)


  • Surveillance and Other Military
  • Space Physics
  • Solar Physics
  • Astronomy

Additional Information

Questions and comments about this spacecraft can be directed to: Dr. H. Kent Hills



NameRoleOriginal AffiliationE-mail
Program ManagerAdvanced Research Project Agency
Dr. Ray W. KlebesadelProject ScientistLos Alamos National
Project ManagerUS Air Force Los Angeles Space and Missile Systems

US Active Archive for Vela 5B Information/Data

The Vela-5B Archive at HEASARC

[Vela 5A and 5B]
Vela 5A and 5B in launch configuration
(credit Los Alamos National Laboratory)

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