Modular Avionics for Habitable Modules: Time-Triggered Ethernet as an Enabling Technology

The increasing complexity of modern space missions, particularly those involving long-duration habitable modules, is pushing traditional federated avionics architectures to their limits. These legacy systems, characterized by dedicated computers for each function and a fragmented mix of low-bandwidth buses, suffer from high mass, complex wiring, and limited scalability, reusability, and in-flight adaptability. This thesis proposes and analyzes a novel crate-based modular avionics architecture designed to address these challenges. The core of the work is the validation of Time-Triggered Ethernet (TTEthernet) as a high-speed and deterministic backbone for inter-crate communication. TTEthernet’s capability to concurrently manage time-triggered, rate-constrained, and best-effort traffic on a single network makes it an ideal candidate to replace legacy bus systems and support mixed-criticality applications that demand higher bandwidth. The practical outcomes include the development of TTEthernet-enabling libraries and tools that allow non-TTE microcontrollers to interface with this technology. A series of experimental tests were conducted to access network performance and potential use cases within the proposed avionics architecture. Furthermore, a novel application-layer synchronization protocol was designed, implemented, and validated. This protocol leverages the underlying TTEthernet synchronization to establish a system-wide time base, enabling all modules within the distributed architecture to share a global conception of time. The findings demonstrate that TTEthernet is a viable and powerful backbone for next-generation modular space avionics. The developed tools and protocols provide the foundation for both prototyping and achieving application-level synchronization essential for complex, distributed, and safety-critical space systems.