Resilience Assurance for Software-Based Space Systems with Online Patching: Two Cases

The paper discusses the problems of resilient software engineering for unmanned software-based space systems. Resilience is achieved by online patching of software upon emergence of defects providing a stable link to the ground control center. Based on the specifics of satellite orbits it offers two case models: a multifragment one—for systems with a continuous link from geostationary orbits; a multiphase one—for recurrent link from elliptic orbits. The results of the modeling offer the possibility to plan the values of the software initial failure rate and the period of preventive tests that would ensure required reliability and availability.