A novel approach based on ion implantation has been developed and used to investigate the influence of a selection of metal and semi-metal ions or their combinations with selected non-metal elements, the implantation energy range, and ion fluencies, on the behaviour of implanted materials under fast atomic oxygen fluxes (FAO). The preferential conditions of single- or multiple-ion implantation in a number of high-performance polymers, graphite and composite materials were examined. Highly stable, oxidation- and erosion-resistant new surface structures were created on graphite, Kapton, PEEK and Mylar, and on carbon-fibre/PEEK composites by exposing the implanted materials to FAO in a unique atomic oxygen beam facility. A number of complementary surface analysis techniques such as RBS, XPS, SEM/EDS were used to study the content and structure of the modified surfaces, and their resistance to oxidation and erosion in FAO conditions.