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The Gas Chromatograph Mass Spectrometer for the Huygens ProbeTitan is unique in the solar system, the only moon that has a dense atmosphere. The major constituents of the atmosphere, nitrogen and methane, are continuously broken apart by a combination of solar UV, impinging electrons from Saturn's magnetosphere, and a steady flow of cosmic rays. The resulting molecular fragments recombine and form a variety of new species, many of which were detected for the first time by Voyager 1. The ubiquitous, surface-hiding aerosol blanket manifests the existence of still more complex compounds. In addition to hydrocarbons and nitriles, the atmosphere is known to contain CO, CO2 and externally delivered H2O. The Gas Chromatograph Mass Spectrometer (GCMS) on the Huygens Probe will measure the chemical composition of the atmosphere of Titan from 170 km altitude (approximately lhPa) to the surface (approximately 1500hPa) and determine the isotope ratios of the major constituents. The GCMS will also analyze gas samples from the Aerosol Collector Pyrolyser (ACP) and may be able to obtain compositional information of several surface materials. The GCMS consists of a quadrupole mass spectrometer (QP) with a secondary electron multiplier ion detector, a three-column gas chromatograph (GC) and an elaborate gas sampling system. The gas sampling system will provide atmospheric samples to the QP for nearly continuous analysis during the Probe descent and batch samples at several altitudes for GC analysis. It also contains a chemical scrubber for noble gas analysis and an enrichment cell for trace constituent enhancement. In addition to the sampling of the atmosphere periodic gas samples, derived from the pyrolysis of aerosols, will be transferred from the ACP to the GCMS for direct QP and full GCMS analysis. The QP can analyze molecular masses from 2 to 14lDalton. The nominal detection threshold is at a mixing ratio of 10E-8. Data rate is 885 bits/sec. The mass of the instrument is 17.3 kg and the energy required for operation during the descent is 110 Watt-hours.
Document ID
20040081406
Acquisition Source
Goddard Space Flight Center
Document Type
Abstract
Authors
Niemann, H. B.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Atreya, S. K.
(Michigan Univ. Ann Arbor, MI, United States)
Bauer, S. J.
(Graz Univ. Austria)
Biemann, K.
(Massachusetts Inst. of Tech. Cambridge, MA, United States)
Carignan, G. R.
(Michigan Univ. Ann Arbor, MI, United States)
Donahue, T. M.
(Michigan Univ. Ann Arbor, MI, United States)
Gautier, D.
(Observatoire de Paris-Meudon France)
Hunten, D. M.
(Arizona Univ. Tucson, AZ, United States)
Israel, G.
(Centre National de la Recherche Scientifique Verrieres-Le Buisson, France)
Lunine, J. I.
(Arizona Univ. Tucson, AZ, United States)
Date Acquired
August 21, 2013
Publication Date
January 1, 2004
Subject Category
Instrumentation And Photography
Meeting Information
Meeting: International Conference on the Occaision of the 375th Birthday of Christiaan Huygens
Location: Noordwijk
Country: Netherlands
Start Date: April 13, 2004
End Date: April 17, 2004
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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