The Results of Ground‐based and In‐flight Testing of Charge‐dissipative and Conducting EKOM Thermal Control Paints

An international program on comparative evaluation of space durability of thermal control paints from a number of countries was initiated a few years ago at ITL with coatings from Russia, France and USA being studied. This paper describes the results of the study on space durability of three types of charge-dissipative and conductive Russian advanced polymer-based EKOM thermal control paints. Extensive ground-based testing in fast atomic oxygen (FAO) beam facilities was used to test the space durability of these paints and the enhancement of their atomic oxygen erosion resistance by a surface modification technology, Photosil (TM). All pristine EKOM paints were also tested in a direct materials exposure experiment on Russian module "Zvezda" onboard the International Space Station.Space durability and change of the major physical properties were evaluated after these experiments using a number of analytical techniques. Both, the ground-based testing and the flight experiments indicated signs of surface erosion with some changes of thermal optical properties. Therefore, the paints were also modified by a surface treatment technology, Photosil (TM), to increase their erosion resistance to atomic oxygen, tested in the same ground-based FAO facilities up to high FAO fluencies and compared with testing results of pristine materials.The comparison indicated that the surface-modified paints exhibit reduced mass loss, full stabilization and no surface morphology changes, thus indicating at full protection from the high FAO fluencies. It was demonstrated that the developed surface modification treatment could be applied successfully to charge dissipative and conductive paints, to enhance the low Earth orbit (LEO) environment resistance of external thermal control coatings in long-term space missions.