Hardware-Based Isolation for Advanced Safety and Security in Spacecraft

AuthorKoisser, David; Brasser, Ferdinand; Jauernig, Patrick; Stapf, Emmanuel; Wallum, Marcus; Fischer, Daniel; Sadeghi, Ahmad-Reza
TypeConference Proceedings
AbstractWith the advent of new mission concepts, such as multi-tenant spacecraft, interconnected spacecraft networks, or AI-supported autonomy, onboard spacecraft software needs to provide a growing number of functionalities. However, as onboard software grows more complex, the probability of software bugs rises as well, becoming an increasingly important factor in spacecraft safety, reliability, and cybersecurity considerations. In this paper, we introduce a novel software architecture for onboard software that builds on a strong hardware-assisted isolation mechanism. Our architecture leverages hardware extensions from Arm processors already deployed today (e.g., in CubeSats) that are becoming common in the space sector. By separating software components into hardware-assisted compartments, we ensure that they cannot affect each other, even when one component crashes. Further, our architecture allows to detect faulty software components and restart them into a safe configuration, reducing dependency on the spacecraft’s safe mode. Especially for missions in which different parties jointly utilize (parts of) a spacecraft, such as hosted payloads or multi-tenant spacecraft, our architecture provides strong safety and cybersecurity guarantees due to the strong separation between components. Due to these properties operating spacecraft becomes inherently more reliable while simplifying onboard software development, as the inherent safety and cybersecurity guarantees reduce the need to extensively test individual software components or auditing of external software. We evaluated our novel software architecture thoroughly on a hardware development board.
Conference17th International Conference on Space Operations (SpaceOps 2023)