Four space application material coatings on the long-duration exposure flight (LDEF)

Technical Report · Sun Nov 01 04:00:00 EST 1992

OSTI ID:6669442

Scialdone, J J; Clatterbuck, C H

Four material coatings of different thickness were flown on the LDEF to determine their ability to perform in the harsh space environment. The coatings, located in the ram direction of the spacecraft, were exposed for 10 months to the low-Earth orbit (LEO) environment experienced by the LDEF at an orbit of 260 nautical miles. They consisted of indium oxide (In2O3), silicon oxide (SiO(x)), clear RTV silicone, and silicone with silicate-treated zinc oxide (ZnO). These coatings were flown to assess their behavior when exposed to atomic oxygen and to confirm their good radiative properties, stability, electrical conductivity, and resistance to UV exposure. The flown samples were checked and compared with the reference unflown samples using high-magnification optical inspection, ESCA analysis, weight changes and dimensional changes. These comparisons indicated the following: The 1000 A SiO(x) coating eroded uniformly, with minor changes in its radiative properties. The 100 A of In2O3 coating eroded completely down to the Kapton backing, with resultant losses of reflectance. The RTV-615 showed erosion, with carbon (C) content losses, while the Si remained constant, with a doubling of the oxygen (O) concentration. The RTV-615 silicone with K2SiO3-treated ZnO changed from flat to glossy white in appearance. It lost C, was etched, and increased its O content. The upper layers showed no remaining Zn or K. Losses of reflectance occurred within certain wavelength bands. It was not possible to evaluate the experimental oxygen reaction rate using the calculated atomic oxygen fluence of 2.6 x 10(exp 20) atoms/cm(exp 2) for the exposure of these coatings during the flight. The bakeout of the coatings was not carried out prior to the flight. Hence, the coating weight and dimensional losses included losses by outgassing products.

• Research Organization: National Aeronautics and Space Administration, Greenbelt, MD (United States). Goddard Space Flight Center
• OSTI ID: 6669442
• Report Number(s): N-93-18370; NASA-TM--104574; REPT--93B00009; NAS--1.15:104574; CNN: RTOP 313-030-09-01-25
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360206* -- Ceramics
Cermets
& Refractories-- Radiation Effects
360606 -- Other Materials-- Physical Properties-- (1992-)
BEHAVIOR
CARBON
CHALCOGENIDES
CHEMICAL COMPOSITION
COATINGS
DIMENSIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON SPECTROSCOPY
ELEMENTS
ENVIRONMENT
EROSION
FILMS
INDIUM COMPOUNDS
INDIUM OXIDES
INSPECTION
LAYERS
LOSSES
NONMETALS
ORGANIC COMPOUNDS
ORGANIC SILICON COMPOUNDS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POLYMERS
RADIATION EFFECTS
SILICON COMPOUNDS
SILICON OXIDES
SILICONES
SILOXANES
SPACE
SPECTROSCOPY
STABILITY
THICKNESS
WEIGHT
ZINC COMPOUNDS
ZINC OXIDES