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Proton 2



Proton 2 was a Soviet magnetospheric research satellite that contained physics experiments to investigate ultra-high-energy cosmic particles and the radiation environment in the vicinity of the Earth.

The Proton 1, 2, and 3 satellites (the N4 series of satellites) were essentially identical. Each satellite was a hermetically sealed cylinder with convex ends. It had four solar arrays mounted in a paddlewheel configuration on top of the cylinder. Total mass was 12,200 kg. There was no onboard propulsion, it was spin-stabilized using gas jets plus what was referred to as a "power damping device". It had antennas protruding from the top and bottom, and a pyramidal truss-like structure on top holding the pickups for the axis-orienting system. Communication was via a beacon operating at 19.910 MHz. Thermal control was maintained using a heat exchanger. It also held chemical fuel cells. The experiments on board were held in a pressurized instrument compartment. the gamma-ray telescope, scintillator telescope, proportional counters, and gas-Cerenkov-scintillator telescope were capable of studying cosmic rays in the range up to 10 million MeV.

Proton 2 launched on 2 November 1965 at 12:28 UT from Baikonur Cosmodrome into a 63.5 degree inclination, 189 x 608 km altitude orbit with a period of 92.6 minutes. The Proton satellites were widely thought to be uncrewed test vehicles for eventual crewed orbital laboratories.

Image from Corliss, 1967

Alternate Names

  • 01701
  • Proton2

Facts in Brief

Launch Date: 1965-11-02
Launch Vehicle: Proton Booster
Launch Site: Tyuratam (Baikonur Cosmodrome), U.S.S.R
Mass: 12200 kg

Funding Agency

  • Unknown (U.S.S.R)


  • Space Physics

Additional Information

Questions and comments about this spacecraft can be directed to: Dr. David R. Williams



NameRoleOriginal AffiliationE-mail

Selected References

  • Corliss, W. R., Scientific satellites, NASA, SP-133, Wash., D.C., 1967.
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