A Modular Flight Software Architecture for In-Orbit Validation of ECC-Protected Memories

Abstract

This paper presents the modular flight software architecture developed for the Robust On-Board Computer (ROBOC), a radiation-experiment payload integrated into the Nanosatellite Error-Resilient Radiation Mission (NASCERR) mission. The proposed system combines a priority-based Real-Time Operating System (RTOS) task pipeline, a register-mapped $\mathbf{I}^{\mathbf{2}} \mathbf{C}$ communication layer, and a fail-safe bootloader with cryptographic validation and automatic rollback. A transparent Field-Programmable Gate Array (FPGA) interposed Static Random Access Memory (SRAM) architecture with selectable Error Correction Code (ECC) schemes and a diagnostic bypass mode enables runtime bit-flip characterization and reproducible comparison between error-correction algorithms. Ground-based validation using a Raspberry Pi On-Board Computer (OBC) emulator demonstrated $\mathbf{1 0 0} \boldsymbol{\%}$ fault-resilience across $\mathbf{8 0 9}$ injected communication anomalies, correct experiment lifecycle management over a soak campaign, and successful firmware update under representative fault scenarios, confirming the system's readiness for Low Earth Orbit deployment.