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A technique for synergistic atomic oxygen and vacuum ultraviolet radiation durability evaluation of materials for use in LEOMaterial erosion data collected during flight experiments such as the Environmental Oxygen Interaction with Materials (EOIM)-3 and the Long Duration Exposure Facility (LDEF) have raised questions as to the sensitivity of material erosion to levels of atomic oxygen exposure and vacuum ultraviolet (VUV) radiation. The erosion sensitivity of some materials such as FEP Teflon used as a thermal control material on satellites in low Earth orbit (LEO), is particularly important but difficult to determine. This is in large part due to the inability to hold all but one exposure parameter constant during a flight experiment. This is also difficult to perform in a ground based facility, because often the variation of the level of atomic oxygen or VUV radiation also results in a change in the level of the other parameter. A facility has been developed which allows each parameter to be changed almost independently and offer broad area exposure. The resulting samples can be made large enough for mechanical testing. The facility uses an electron cyclotron resonance plasma source to provide the atomic oxygen. A series of glass plates is used to focus the atomic oxygen while filtering the VUV radiation from the plasma source. After filtering, atomic oxygen effective flux levels can still be measured which are as high as 7 x 10(exp 15) atoms/cm(exp 2)-sec which is adequate for accelerated testing. VUV radiation levels after filtering can be as low as 0.3 suns. Additional VUV suns can be added with the use of deuterium lamps which allow the VUV level to be changed while keeping the flux of atomic oxygen constant. This paper discusses the facility, and results from exposure of Kapton and FEP at pre-determined atomic oxygen flux and VUV sun levels.
Document ID
19960029119
Document Type
Conference Paper
Authors
Rutledge, Sharon K. (NASA Cleveland, OH United States)
Banks, Bruce A. (NASA Cleveland, OH United States)
Date Acquired
September 6, 2013
Publication Date
May 1, 1996
Subject Category
Chemistry and Materials (General)
Report/Patent Number
NAS 1.15:107230
E-10268
NASA-TM-107230
Meeting Information
International Conference on Protection of Materials and Structures from the Low Earth Orbit Space Environment(Toronto)
Funding Number(s)
PROJECT: RTOP 233-1A-1E
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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