Hardening On-Board Software: a Low-Overhead Compiler-based Approach

As challenges related to system complexity, cost, weight, power consumption, and real-time performance are increasingly crucial, mixed-criticality systems become more common in low-cost space avionics. Radiation-induced transient faults further complicate the design, as conventional mitigation strategies exacerbate these issues. This work presents REDDI, a selective Software Implemented Hardware Fault Tolerance (SIHFT) technique that applies fault tolerance at compilation time by recursively protecting developer-annotated resources. We detail this method, introduce the concept of software spheres, and address key implementation challenges. The approach is evaluated on a set of benchmarks and a real-world mixed-criticality on-board software for experimental sounding rockets, running on an STM32-based on-board computer. Results demonstrate a significant reduction in the overhead typically associated with SIHFT, while maintaining a high fault detection rate in critical code sections, proving the effectiveness of the proposed solution.