College - Author 1
College of Engineering
Department - Author 1
Aerospace Engineering Department
Degree Name - Author 1
BS in Aerospace Engineering
Kira Abercromby, College of Engineering, Aerospace Engineering Department
The Aerospace Engineering Space Environments Laboratory at California Polytechnic State University features a ground-based system capable of generating atomic oxygen (AO) and vacuum ultraviolet (VUV) radiation environments, constructed by Max Glicklin in 2012. Experiments using three different spacecraft materials were conducted to test the individual and synergistic effects of these naturally occurring phenomena. Kapton HN functioned as a means to provide initial validation of the presence of AO and VUV radiation. Kapton HN also functioned as a test-fluence standard during testing of two other materials. These materials included aluminized beta cloth, with the non-aluminized side being tested, and Indium-Tin-Oxide (ITO) coated aluminized Kapton, with the ITO side being tested. Primary test durations were 24 hours, although a 12 hour test was also completed. Most 24 hour tests exhibited AO fluences of approximately 1.1 x 1021 atom·cm-2, or roughly equivalent to four months on-orbit at International Space Station altitude. Vacuum ultraviolet exposure was performed at a sun power of 4.5 G, or roughly equivalent to 108 hours on-orbit for a 24 hour test. Material degradation was observed via mass loss measurements, scanning electron microscope (SEM) images, and reflectance measurements using a diffuse spectrometer. For all test conditions described in this report, all three sample types did not experience observable increases or decreases in degradation due to simultaneous exposure to AO and VUV as opposed to single AO exposure. The beta cloth samples performed as expected, with little degradation relative to the Kapton HN samples. The ITO coated samples did not resist degradation as was expected and featured large changes in surface optical properties, despite negligible mass loss. Because the synergistic effects of AO and VUV are known but no synergistic effects were observed outside the margin of error for the measurements, longer test durations are required in order observe the synergistic effects.