Determination of the Reactivity of Copper with Atomic Oxygen

In low Earth orbit (LEO), the composition of the atmosphere is dominated by atomic oxygen which is a major determinant of material degradation of external surfaces and a critical determining factor of spacecraft life. To simulate the effects of atomic oxygen in LEO, thin films of copper were exposed to a laboratory atomic oxygen beam. Copper films were characterized both before and after exposure by a variety of surface sensitive techniques including thin film x-ray diffraction, optical reflectance measurements, high resolution profilometry, and x-ray photoelectron spectroscopy. The results of these ground based experiments were compared to actual flight data acquired from the Space Shuttle based CONCAP-II experiment which exposed various materials in LEO on ambient and 320°C hot plates. The similarity of results generated from exposure of copper in an atomic oxygen beam to actual flight results prove that ground based atomic oxygen experiments can be good simulations of the LEO environment.