Structural material selection and processing for low earth orbit spacecraft regarding atomic oxygen effects

In this paper structural material selection and surface processing considerations problem for low earth orbit (LEO) spacecraft is discussed. In order to limit this broad subject, discussion is focused especially on "Atomic Oxygen Effect", that is crucial for structures. Atomic Oxygen (AO) constitutes the most severe impact on material degradation and erosion. However other environmental effects like, space debris, outgassing, solar and cosmic radiation cannot be ignored. Two types of materials used for satellite structures are polymers and metals. Polymers suffer more than metals when exposed to AO, yet their outstanding properties make them popular in space applications. Polymers are preferable in the sense that they save weight due to their low densities and have better thermal insulation performance. Moreover, for electronics and optical equipments they are widely used. On the other hand, metallic materials are also prone to degradation, albeit less then polymers. Metals, certainly, could maintain the optimum structural integrity. Since designers do not sacrifice for the properties of polymers and metals, new techniques have been conducted to overcome the AO problem so that special surfaces have been constructed to serve as AO barriers