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Micrometeoroid Detector and Analyzer

NSSDCA ID: 1976-003A-12

Mission Name: Helios-B
Principal Investigator:Dr. Hugo Fechtig


The purpose of this experiment (E10) was to investigate some theories about the interplanetary dust including whether -- (1) the number of particles increased toward the sun, (2) the cutoff for small particles was dependent on the distance from the sun, because solar pressure increases nearer the sun, and (3) the number densities of particles changed near the orbits of planets. The detector utilized the fact that the kinetic energy of dust particles hitting a target with high velocity (several km/s) caused the material to vaporize and become partically ionized. The generated plasma cloud was separated by approproate voltages into its negative (electron) part and into positive ions. From the impulse heights, the mass and the energy of the dust particles were determined. A time-of-flight mass spectrometer in connection with the target allowed the small ion cloud to be analyzed, making possible the investigation of the chemical composition of the dust particles. The threshold for the detection of a particle was about 1.E-15 g. Mass and energy determination was possible for particles larger than about 1.E-14 g. For particles larger than 1.E-13 g, a mass spectrum could be gathered. For further details, see pp 268-269 of "Raumfahrtorschung," 19, 5, Sept./Oct. 1975.

Alternate Names

  • Helios-B/MicrometeoroidDetectorandAnalyzer

Funding Agency

  • Bundesministerium fuer Wissenschaftliche Forschung (Federal Republic of Germany)


  • Space Physics: Zodiacal Light/Interplanet Dust
  • Planetary Science: Small Bodies

Additional Information

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



NameRoleOriginal AffiliationE-mail
Mr. J. WeihrauchOther InvestigatorMax-Planck-Institut fur Physik und Astrophysik
Dr. Hugo FechtigPrincipal InvestigatorMax-Planck-Institut fur Kernphysik
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