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Solar Plasma Spectrometer

NSSDCA ID: 1962-041A-06

Mission Name: Mariner 2


This experiment was designed to study the flux and energy spectrum of the positive ion component of the solar wind plasma. The instrument consisted of a cylindrical electrostatic analyzer with a Faraday cup detector. This system separated positively-charged ions according to their energy per unit charge. The entrance aperture was 5 sq cm and rectangular. The aperture pointed to within 0.1 degree of the sun throughout the flight. The voltage on the analyzer plates was changed at intervals of about 18 s in an ascending sequence of 10 values from 231 V to 8824 V. A zero current reading and a calibration reading were then taken. The complete sequence of 12 measurements was repeated every 3.696 minutes (every 2.016 minutes near Venus). The instrument functioned normally over the entire flight and provided data almost continuously until December 30, 1962.

Alternate Names

  • Mariner2/SolarPlasmaSpectrometer

Facts in Brief

Mass: 2.18 kg
Power (avg): 1 W


  • Planetary Science: Fields and Particles
  • Space Physics: Heliospheric Studies

Additional Information

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



NameRoleOriginal AffiliationE-mail
Dr. Conway W. SnyderCo-InvestigatorNASA Jet Propulsion Laboratory

Selected References

  • Josias, C., and J., Jr. Lawrence, Instrument for the measurement of interplanetary solar plasma, JPL, Calif. Inst. Technol., TR 32-492, Pasadena, CA, May 1964.
  • Neugebauer, M., and C. W. Snyder, Solar-wind measurements near Venus, J. Geophys. Res., 70, No. 7, 1587-1591, doi:10.1029/JZ070i007p01587, Apr. 1965.
  • Neugebauer, M., and C. W. Snyder, The mission of Mariner II: Preliminary observations, solar plasma experiment, Science, 138, No. 3545, 1095-1096, doi:10.1126/science.138.3545.1095, Dec. 1962.
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