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Secondary ion mass spectrometry (SIMS) analysis of hypervelocity microparticle impact sites on LDEF surfacesTwo dimensional elemental ion maps have been recorded for hundreds of microparticle impact sites and contamination features on LDEF surfaces. Since the majority of the analyzed surfaces were metal-oxide-silicon (MOS) impact detectors from the Interplanetary Dust Experiment, a series of 'standard' and 'blank' analyses of these surfaces are included. Hypervelocity impacts of forsterite olivine microparticles on activated flight sensors served as standards while stylus and pulsed laser simulated 'impacts' served as analytical blanks. Results showed that despite serious contamination issues, impactor residues can be identified in greater than 1/3 of the impact sites. While aluminum oxide particles could not be detected on aluminum surfaces, they were detected on germanium surfaces from row 12. Remnants of manmade debris impactors consisting of paint chips and bits of metal were identified on surfaces from LDEF Rows 3 (west or trailing side), 6 (south), 9 (ram or leading side), 12 (north) and the space end. Higher than expected ratios of manmade microparticle impacts to total microparticle impacts were found on the space end and the trailing side. These results were consistent with time-tagged and time-segregated microparticle impact data from the IDE and other LDEF experiments. A myriad of contamination interferences were identified and their effects on impactor debris identification mitigated during the course of this study. These interferences include pre-, post and inflight deposited surface contaminants as well as indigenous heterogeneous material contaminants. Non-flight contaminations traced to human origins, including spittle and skin oils, contributed significant levels of alkali-rich carbonaceous interferences. A ubiquitous layer of in-flight deposited silicaceous contamination varied in thickness with location on LDEF, even on a micro scale. In-flight deposited (low velocity) contaminants include urine droplets and bits of metal film from eroded thermal blankets.
Document ID
19950017416
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Simon, C. G.
(Institute for Space Science and Technology, Inc. Gainesville, FL, United States)
Buonaquisti, A. J.
(North Carolina State Univ. Raleigh, NC., United States)
Batchelor, D. A.
(North Carolina State Univ. Raleigh, NC., United States)
Hunter, J. L.
(North Carolina State Univ. Raleigh, NC., United States)
Griffis, D. P.
(North Carolina State Univ. Raleigh, NC., United States)
Misra, V.
(North Carolina State Univ. Raleigh, NC., United States)
Ricks, D. R.
(North Carolina State Univ. Raleigh, NC., United States)
Wortman, J. J.
(North Carolina State Univ. Raleigh, NC., United States)
Brownlee, D. E.
(Washington Univ. Seattle, WA., United States)
Best, S. R.
(Auburn Univ. AL., United States)
Date Acquired
September 6, 2013
Publication Date
February 1, 1995
Publication Information
Publication: NASA. Langley Research Center, LDEF: 69 Months in Space. Third Post-Retrieval Symposium, Part 1
Subject Category
Inorganic And Physical Chemistry
Accession Number
95N23836
Funding Number(s)
CONTRACT_GRANT: NAG1-1218
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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