Impact of Film Thickness on the Spectroscopic Evolution of Polyimides in a Simulated GEO Environment

Space domain awareness (SDA) is becoming more important with a constantly increasing number of artificial objects in space. Astronomical reflectance spectroscopy (ARS) is a promising technique employed for remote characterization of space objects. In geosynchronous earth orbit (GEO), the chemical characteristics of a material change continuously, as it is exposed to the harsh radiation environment of several damaging species (with electrons being the primary damaging species in terms of energy deposition). These chemical modifications alter the light absorbed by and reflected from the object at certain wavelengths, resulting in a concomitant change of the measured object’s brightness and color index. By understanding the evolution of the color index of a material as a function of time on orbit, ARS can become a powerful tool for remote characterization of space objects as well as anomaly characterization and resolution. In this study, we investigate the effect of a space-simulated environment represented by high-energy (100 keV) electrons on the evolution of optical properties of several spacecraft-relevant polymer materials.