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Electron Spectrometer

NSSDCA ID: 1965-060A-02

Mission Name: Pegasus 3
Principal Investigator:Mr. Richard A. Potter


An electron spectrometer that consisted of a shielded scintillator with a photomultiplier tube was used to obtain data on the actual radiation environment experienced by satellites and to provide more detailed radiation mapping of the south Atlantic magnetic anomaly. The sensor was mounted at the forward end of the spacecraft center structure and pointed approximately in the +Z direction. The detector was omindirectional and had two counting channels with energy thresholds of 0.1 and 2.0 MeV. A light shield was used to stop protons with energies of less than 3 MeV, and an anticoincidence system negated signals from particles with energies greater than 11 MeV. Corrections from other information sources had to be made to the final data for protons with energies between 3 and 11 MeV. Information from the detector consisted of two voltages representing the count rates of particles with energies greater than 0.1 and 2.0 MeV. The voltages were stored on board and were telemetered as two parts of a pcm word. The radiation experiment operated well from launch until September 14, 1965, when measured flux levels in channel A were consistently shown to be about one order of magnitude lower than fluxes observed previously. Channel B continued to send data that were in good agreement with data from Pegasus 1 and 2.

Alternate Names

  • Pegasus3/ElectronSpectrometer


  • Space Physics: Magnetospheric Studies

Additional Information

Questions and comments about this experiment can be directed to: Coordinated Request and User Support Office



NameRoleOriginal AffiliationE-mail
Mr. Richard A. PotterPrincipal InvestigatorNASA Marshall Space Flight Center
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