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Space Durability of Polymer Films Titles |
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Titles:
Dever, J. A., Miller, S. K., Sechkar, E. A,
and
Wittberg, T. N., “Preliminary Analysis of Polymer Film Thermal
Control
and Gossamer Materials Experiments on Materials International Space
Station
Experiment (MISSE 1 and MISSE 2),” in proceedings of the 2006 MISSE
Post-Retrieval
Conference sponsored by the Air Force Research Laboratory, Orlando,
Florida,
June 26 – 30, 2006. A total of 31 samples were included in the National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) Polymer Film Thermal Control (PFTC) and Gossamer Materials experiments, which were exposed to the low Earth orbit environment for nearly 4 years on the exterior of the International Space Station (ISS) as part of the Materials International Space Station Experiment (MISSE 1 and MISSE 2). MISSE is a materials flight experiment sponsored by the Air Force Research Lab/Materials Lab and NASA. This paper describes objectives, materials, and characterizations for the MISSE 1 and MISSE 2 GRC PFTC and Gossamer Materials samples. Samples included films of polyimides, fluorinated polyimides, and TeflonÒ fluorinated ethylene propylene (FEP) with and without second-surface metalizing layers and/or surface coatings. Also included were films of polyphenylene benzobisoxazole (PBO) and a polyarylene ether benzimidazole (TOR-LMTM). Polymer film samples were examined post-flight for changes in mechanical and optical properties. The environment in which the samples were located was characterized through analysis of sapphire contamination witness samples and samples dedicated to atomic oxygen (AO) erosion measurements. Results of the preliminary analyses of the PFTC and Gossamer Materials experiments are discussed.
Dever, J. A., Miller, S. K., Sechkar, E. A., “Effects of the Space Environment on Polymer Film Materials Exposed on the Materials International Space Station Experiment (MISSE 1 and MISSE 2),” in proceedings of the 10th International Symposium on Materials in a Space Environment & 8th International Conference on Protection of Materials and Structures in a Space Environment, Collioure, France, June 19 – 23, 2006. A total of 28 polymer film samples were included in the National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) Polymer Film Thermal Control (PFTC) and Gossamer Materials Experiments, which were exposed to the low Earth orbit environment for nearly 4 years on the exterior of the International Space Station (ISS) as part of the Materials International Space Station Experiment (MISSE 1 and MISSE 2). MISSE is a materials flight experiment sponsored by the Air Force Research Lab/Materials Lab and NASA. This paper will describe objectives, materials, and characterizations for the MISSE 1 and MISSE 2 GRC PFTC and Gossamer Materials samples. Samples included films of polyimides, fluorinated polyimides, and TeflonÒ fluorinated ethylene propylene (FEP) with and without second-surface metalizing layers and/or surface coatings. Also included were films of polyphenylene benzobisoxazole (PBO) and a polyarylene ether benzimidazole (TOR-LMTM). Polymer film samples were examined post-flight for changes in mechanical and optical properties and for atomic oxygen (AO) erosion. Results of the preliminary analyses of the PFTC and Gossamer Materials Experiments are discussed.
Vacuum ultraviolet radiation is among the space environment
elements
that can be hazardous to DC93-500 silicone film, which has been
proposed
for use on spacecraft exterior surfaces. Investigations have been
conducted
to examine vacuum ultraviolet effects on DC93-500 film.
Laboratory exposure
tests were used to determine the effectiveness of various wavelength
ranges
in causing optical and mechanical degradation and to determine
intensity-dependence
of optical and mechanical properties degradation. Results
indicated that
wavelengths between 185 nm and 200 nm were significantly more effective
in
causing degradation than wavelengths between 140 nm and 185 nm.
These findings
were consistent with results of vacuum ultraviolet ellipsometric
optical
measurements which provided data on depth of penetration in DC93-500 as
a
function of wavelength. Wavelengths between 185 and 200 nm
penetrate to
depths between 1 m and 3 m in DC93-500, depths where bulk degradation
is
likely, whereas the penetration of shorter wavelengths is much more
shallow
and more likely to result only in surface degradation. Results of
exposures
of DC93-500 film samples to vacuum ultraviolet of intensities between
1.5
and 5.5 times the sun’s intensity indicated no intensity-dependence of
optical
and mechanical property degradation.
Joyce Dever, Bruce Banks, and Li Yan, “Vacuum
Ultraviolet Radiation Effects on Dow Corning (DC) 93-500 Silicone Film,”
(presented at the “7th International Conference on Protection of
Materials
and Structures in the Space Environment (ICPMSE),” held in Toronto,
Canada,
May 2004), in Kleiman, Jacob I. (Ed.), Protection of Materials and
Structures
from the Space Environment: ICPMSE-7, Springer Publishing, 2006. A space-qualified silicone polymer (Dow Corning DC93-500) has
been
used as a spacecraft solar cell adhesive and has been more recently
proposed
for use in a Fresnel lens solar concentrator for space power
applications.
Potential future applications of DC93-500 for exterior spacecraft
surfaces
require an understanding of its overall space environment
durability. Vacuum
ultraviolet (VUV) radiation is among the space environment elements
that
can be hazardous to the properties of DC93-500. This paper
describes investigations
into the effects of VUV radiation on DC93-500 silicone film. |
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