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Molecular and Elemental Dust Analyzer (MEDA) for the comet rendezvous asteroid flyby missionComets are some to the most primitive bodies in the solar system and therefore should contain elemental, chemical, and isotopic records of the early history of the solar system. An opportunity to perform in situ analyses of a comet nucleus exists with the Comet Rendezvous Asteroid Flyby (CRAF) mission. An integrated gas chromatograph/X-ray fluorescence instrument (MEDA), being proposed for inclusion onboard the CRAF spacecraft, will measure the molecular and elemental constituents of collected dust grains and ices. The gas chromatograph, employing helium ionization detectors and three columns designed to separate light gases, polar gases, and hydrocarbons will measure the volatile compounds of the biogenic elements thermally released from collected dust grains. The sensitivity of the GC for compounds of interest is at the picogram level. X-ray fluorescence utilized cryogenically cooled Si(Li) solid state detectors of nominal 150 eV resolution at 5.9 keV. Based on laboratory work with carbonaceous meteorites, both the GC and XRF can perform meaningful analyses with a few micrograms of collected comet dust.
Document ID
19860017385
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Ohara, B. J.
(NASA Ames Research Center Moffett Field, CA, United States)
Carle, G. C.
(NASA Ames Research Center Moffett Field, CA, United States)
Clark, B. C.
(Martin Marietta Aerospace Denver, Colo., United States)
Date Acquired
August 12, 2013
Publication Date
May 1, 1986
Publication Information
Publication: NASA, Washington Second Symposium on Chemical Evolution and the Origin and Evolution of Life
Subject Category
Space Biology
Accession Number
86N26857
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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