Dielectric Materials for Electrical Engineering

Chapter 21

Dielectric Coatings for the Thermal Control of Geostationary Satellites: Trends and Problems 1

21.1. Introduction

Space is a complex and dynamic medium. It is filled with gravitational fields, made up of matter whose density becomes extremely weak, traversed by cosmic radii and by a very wide spectrum of corpuscular radiations, but also occupied by intense magnetic fields (of a greater/lesser extent). Furthermore, as they are connected by a very strong synergy, its components cannot be considered separately. Compatibility with such an environment is an essential element in the conception of any space vehicle. The constant quest for high reliability, a long lifetime and a high degree of autonomy, associated with the choice of an orbit and selection of materials, etc. means that all natural and/or artificial stresses need to be taken into account in order to best design space systems, sub-systems and equipment. On a satellite, the good functioning of any piece of equipment depends on its temperature. If temperature regulation is often made “naturally” in our terrestrial environment or in our laboratories, this is not the case in environment of space, where the obtaining of a correct temperature can only be achieved as a result of a specific science and technology called “thermal control of space vehicles”. Thermal control uses passive solutions as much as possible, i.e. thermal control radiators and external insulation. The materials brought into play are essentially dielectric ...