Measurements of optically transparent and mirrored specimens from the POSA, LDEF A0034, and EOIM-III space flight experiments

Deposition of molecular contamination onto spacecraft surfaces changes the thermo-optical and electrical properties of those surfaces. Such changes may induce changes in the properties and performance of other spacecraft systems. Interactions with space environments may continue to change the nature of contaminant species on surfaces, causing time-varying effects on other hardware. For these reasons there is a continuing interest in the properties of deposited thin films. Spectroscopic and surface measurement results are presented for fused silica and other optically transparent specimens, as well as selected first surface mirror materials from the POSA, LDEF A0034, and EOIM-III space flight experiments. A simple empirical model was used to relate the change in optical transmission of fused silica due to contamination deposits. Transmission or reflectance measurements were taken from vacuum UV wavelengths out to the mid-IR region of the spectrum. These results show that the contamination effects are most significant at wavelengths less than 400 nm.