Acceleration of resource tests of spacecraft polymers for resistance to long-term influence of atomic oxygen in the Earth ionosphere

The procedure of accelerated resource tests of spacecraft polymers for their resistance to the long-term influence of atomic oxygen (AO) in the Earth's ionosphere at altitudes from 200 to 700 km has been developed. The procedure involves irradiation of polymers with high-energy ions of atomic oxygen and the use of a kapton-H polyimide as reference material. The condition of equivalence of the " atomic oxygen - polymer" interaction in the ionosphere and on the laboratory set is the equality of tested material mass loss. The basis for substantiating the procedure of accelerated tests is the result: when irradiating the kapton-H polymer with high-energy atomic oxygen ions in the energy range from 30 to 80 eV, the degradation of polyimide is determined by the process of chemical etching of the material. To substantiate the procedure of accelerating resource tests of polymeric structural materials of spacecraft for resistance to long-term action of atomic oxygen flows, the dependences of mass loss and volumetric mass loss factor (reactivity) of kapton-H polyimide and Teflon FEP-100A on fluence and energy of the atomic oxygen ions have been obtained. It is shown that when irradiating kapton-H polyimide with atomic oxygen ions with the energy of 30 to 80 eV, the material mass loss due to chemical etching is about an order of magnitude greater than the mass loss due to kinetic sputtering. When the kapton-H polymer is irradiated with high-energy atomic oxygen ions, the coefficient of acceleration of the resource tests and the fluence of atomic oxygen are about two orders of magnitude greater than the coefficient of acceleration obtained using atomic oxygen ions with an energy of 5 eV.