The Design of a Modular Avionics System for Spaceshot Liquid Rockets

Avionics systems in high-performance collegiate liquid rocketry are crucial for data acquisition, control, and recovery. However, these systems are often custom-built for each vehicle, requiring repetitive research and development, which extends timelines and leads to worse results. This paper discusses the design of a modular, customizable avionics system developed by the Yellow Jacket Space Program, which includes both flight and ground hardware and software components. The Yellow Jacket Space Program simultaneously operates two vehicle programs, and an engine development and testing program. The goal of streamlining avionics development led to the creation of a highly modular, easily revisable, and efficient avionics system. The system is split up into a flight system and a ground subsystems: the flight system focuses on controlling the propulsion system, acquiring vehicle sensor data, estimating its position and heading, and providing a recovery signal upon the rocket landing, while the ground system allows operators to observe and control vehicle states by receiving live data from sensors and controlling valves. Central to YJSP avionics is the System Avionics Module (SAM) printed circuit board (PCB), which provides localized valve control and data acquisition of current loop sensors, thermocouples, resistance temperature detectors, and differential sensors, transmitting live data to a custom GUI operated in mission control. The flight system utilizes the SAM, along with seven other custom PCBs, to meet the primary and secondary requirements, including live data transmission during flight. All components in the system are programmed using Rust to create memory safe code and eliminate unexpected errors. Devices are programmed with custom firmware to enable efficient data acquisition and guarantee expected performance. The avionics system topology discussed in this paper allows for rapid testing and revision of individual components while enabling YJSP to adapt to future vehicle programs regardless of new requirements.