Comprehensive methodology and best practices for On-Board Computer system engineering design: Lessons learned from CHASQUI-II nanosatellite development in the APSCO CubeSat program

Tapia Gallardo J.A.; Future Mendieta R.C.; Choque Quispe S.K. · Proceedings of the International Astronautical Congress, IAC (2024) · DOI: 10.52202/078365-0151

Resumen

This work delineates the methodology and lessons learned from designing the on-board computer system for the Chasqui-II nanosatellite, developed by the Universidad Nacional de Ingeniería in Lima, Peru. The scientific mission of Chasqui-II centers around investigating Energetic Particle Precipitation (EPP) in low latitudes induced by SuperBolts, specifically during the peak occurrence months from November to February. A comparative analysis was conducted to select the appropriate microcontroller, following the European Cooperation for Space Standardization (ECSS) guidelines. The STM32F446RE microcontroller emerged as the optimal choice, considering crucial factors such as processing capability, power consumption, operating temperature and voltage, and EO compatibility. Subsequently, the operating modes were defined: boot (initiated after the power supply from the Energy Power System), deployment (antennas and solar panels are deployed), safe (an emergency state in case of any nominal failure), nominal (default operational state) and transmitting (for data transmission to the ground station). The software architecture was selected to ensure the incorporation of functions for the reception, routing, and execution of telecommands. Programming of the selected microcontroller prioritized low coupling and high cohesion to ensure maintainability and facilitate debugging. Simulations and basic hardware testing were conducted to assess reliability and the efficacy of the system. In essence, this work aims to provide a comprehensive methodology, and best practices guide and pitfalls to avoid, assisting prospective students in developing their first OBC system. Copyright

Instituciones: Universidad Nacional de Ingeniería