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Dust Mass Spectrometer (PUMA)

NSSDC ID: 1984-125A-04
Mission Name: Vega 1
Principal Investigators: Dr. Jochen Kissel, Dr. Roald Z. Sagdeev, Dr. Jean-Loup C. Bertaux


This investigation (PUMA) was designed to estimate the mass and chemical composition of particles in the dust coma. A similar instrument will be flown on the Giotto spacecraft. The instrument was mounted parallel to the relative velocity vector and analyzed the chemical and isotopic composition of individual dust particles. Impact of a dust particle on the instrument's silver target area caused a plasma to be formed consisting of dust and target material, from which ions were extracted by a 1.5-kV electric field. The ions traveled through a time-of-flight tube (actually two tubes with an electrostatic reflector between, with total length of 1 m) where they were separated according to their mass before being recorded by an electron multiplier. The ion mass range was 1 to 100 u, with resolution M/(delta M) of 200. The instrument observed the spectra of the most common dust particles, which were expected to be in the size range 100 to 10,000 nm. The instrument was sensitive to dust particles in the mass range 3E-16 to 5E-10 g.

Alternate Names

  • PUMA

Facts in Brief

Mass: 19.0 kg
Power (avg): 31.0 W
Bit rate (avg): 10.24 bps


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

Additional Information

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



NameRoleOriginal AffiliationE-mail
Dr. Jochen KisselPrincipal InvestigatorMax-Planck-Institut fur Kernphysik 
Dr. Roald Z. SagdeevPrincipal InvestigatorInstitut Kosmicheskich Issledovaniya (IKI)
Dr. Jean-Loup C. BertauxPrincipal InvestigatorCNRS, Service d'
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