Atomic Oxygen Protection of Materials in Low Earth Orbit

Spacecraft polymeric materials as well as polymer-matrix carbon-fiber composites can be significantly eroded as a result of exposure to atomic oxygen in low Earth orbit (LEO). Several new materials now exist, as well as modifications to conventionally used materials, that provide much more resistance to atomic oxygen attack than conventional hydrocarbon polymers. Protective coatings have also been developed which are resistant to atomic oxygen attack and provide protection of underlying materials. However, in actual spacecraft applications, the configuration, choice of materials, surface characteristics and functional requirements of quasi-durable materials or protective coatings can have great impact on the resulting performance and durability. Atomic oxygen degradation phenomena occurring on past and existing spacecraft will be presented. Issues and considerations involved in providing atomic oxygen protection for materials used on spacecraft in low Earth orbit will be addressed. Analysis of in-space results to determine the causes of successes and failures of atomic oxygen protective coatings is presented.