Investigation of the Influence of Ionization Radiation on Glassy Carbon Coatings, after Long Stay in the Outer Space on the International Space Station (ISS)

Abstract

In this study two types of samples of spectrally pure graphite, compacted and coated with glassy carbon, were analyzed with liquid scintillation spectrometry, scanning electron microscopy (SEM) and X-ray diffractometry (XRD). “Space” sample has been sent in outer space on the surface of ISS for 28 months. “Space” sample is compared with “reference” sample, made of the same material, but stored on Earth for the same period. Radiation environment data were collected using R3DR2-Lyulin instrument, located in the outer space very close to the samples, in the same module of ISS. The effect of cosmic radiation leads to slight increase of 14C content, detected by liquid scintillation spectrometry. SEM and thermal test using XRD did not show any noticeable changes in terms of structure and phase composition. This confirms the high degree of reliability of this material under significantly milder operating conditions in Earth orbit.