Space Environmental Effects on Silvered Teflon Thermal Control Surfaces

Cumulative space environmental effects on AgFEP were a function of exposure orientation. Samples from 19 silvered Teflon AgFEP thermal control surfaces recovered from the Long Duration Exposure Facility IDEF have been analyzed to determine changes in this material as a function of position on the spacecraft. Although solar absorptance and infrared emittance of measured thermal blanket specimens are relatively unchanged from control specimen values, significant changes in surface morphology, composition, and chemistry were observed. All AgFEP surfaces exposed to high atomic oxygen flux rows 7-11, irrespective of exact angle, had a uniformly cloudy appearance due to surface erosion. Scanning electron microscopy SEM showed a surface topography with sharp peaks and valleys, while x-ray photoelectron spectroscopy XPS detected a surface composition corresponding to contamination-free FEP, with less than 1 mole oxygen.