Open Source Port of NASA's Core Flight System to FreeRTOS in Arm Cortex-M-Based Microprocessor

Space systems are increasingly complex. To address the challenge of reducing cost and schedule, NASA has provided a set of reusable components for flight software. This work presents an implementation of NASA's Operating System Abstraction Layer (OSAL) for the FreeRTOS operating system running on an Arm Cortex-M microprocessor, along with a case study mission based on NASA's Core Flight System (cFS). Neutron irradiation is used as a preliminary method to assess the software reliability in the presence of radiation-induced soft errors. Benchmark applications are tested in two scenarios: running directly on FreeRTOS and within the cFS framework. The results show that the overhead of cFS negatively affects reliability, increasing the dynamic cross-section by up to 51 %. However, this comes with the benefits of software portability and the reuse of components with proven flight heritage.