Radiation damage behavior of carbon/carbon composite in Low Earth Orbit environment

To understand the degradation behavior of Carbon/Carbon(C/C) composite in LEO radiation environment, groups of 2D-C/C composites samples were exposed to ground-based Low Earth Orbit(LEO) simulating facilities. The LEO radiating environment covers part of Van Allen inner belt, which contains atomic oxygen(AO) and highenergy proton radiating regions. These two kinds of radiating sources were arranged for simulating the real LEO radiating conditions regarding to the first orbit movement speed of serving space shuttles. Changes of microstructure, mass loss, surface roughness, chemical construction and thermal physical properties after environmental assessment were analyzed and compared to understand the damage behavior of LEO radiation on C/C composite. It was found that AO is the main factor of mass loss in LEO radiating particles. The charged highenergy protons have an aggravating damage ability with energetic AO, damage situations of degree in orbit down process is more serious than in orbit rising process. The LEO radiation damage mechanisms of C/C composite are revealed and expounded either.