The decrease in visible and ultraviolet transmission spectra of polymeric and glass spacecraft materials has been measured to determine the extent of degradation due to high energy UV radiation similar to the solar spectrum (both above and below the stratosphere). This project looked at the effects that the atmosphere has in regards to blocking UV radiation and thus, slowing down the UV degradation process. Materials such as quartz, borosilicate glass, sodium glasses, polyethylene, polyimide, and polyethylene terephthalate polymers were exposed to radiation from a focused high intensity deuterium lamp source, which generates radiation in the UVA and UVB spectrum. Duplicates of each sample were exposed to the radiation for the same amount of time both in and out of vacuum to compare the rate at which the materials degrade. A particularly severe effect might result from atmospheric oxygen exposed to intense UV radiation which can produce atomic oxygen. The materials’ UV/VIS/NIR ( ̴200nm to 1700nm) were examined with a fiber optic spectrometer to determine the effects of being exposed to the radiation and to the pressure of atmospheric gases.
Available at: http://works.bepress.com/katie-gamaunt/4/