The study of the diagnosing of automatic spacecraft on-board equipment using a discrete-event simulation model

Features of functioning of spacecraft with a high level of autonomy as objects of technical diagnosis are considered. It is assumed that on-board monitoring and diagnostic functions are autonomous and refer to ground facilities when it is impossible to solve problems of recognition of abnormal situations and restore the operational state of on-board equipment. Diagnosing of on-board equipment is described using a state graph that takes into account the peculiarities of the abnormal situations detection by airborne and ground-based means. The developed simulation model allows taking into account the accumulation of consequences of onboard equipment failures due to the influence of the environmental factors of near space and the change in the intensity of their occurrence. The results of simulation modeling of spacecraft diagnosing by means of on-board and terrestrial means of the information telemetry system are presented. The importance of a terrestrial segment of the information telemetry system for the spacecraft control during the periodical and in-depth analysis of their technical condition is shown. The impact of reliability of onboard equipment diagnosis on the autonomy level of Earth remote sensing spacecraft by the simulation results is analyzed.