An open-source modular avionics platform for small experimental rockets

Abstract

Small experimental rockets require avionics that can be adapted to changing missions and onboard experiments. This work presents ELECTRA, an open-source modular avionics platform with integrated navigation and mission management. The platform combines function-specific stacked circuit boards with firmware organized into device-specific drivers and function-specific tasks, providing a working reference implementation for modifying selected functions while reusing existing hardware and software. The available designs and firmware allow researchers to inspect and adapt both the hardware configuration and the internal operation of state estimation and mission decision-making. Reconfiguration was demonstrated through bench tests of radio-frequency (RF) board replacement and Mission input/output (I/O) expansion board addition. Both steps retained the Main and Power/interface boards and the global navigation satellite system (GNSS)/magnetometer board, with the required firmware changes documented and communication and output operation verified. Complementary evaluations using task activation timing measurements, a ground-motion comparison with an independent navigation reference, and TAURUS-II flight records characterized the integrated implementation’s operating characteristics and demonstrated its application in flight. Editable hardware designs, manufacturing files, baseline and reconfiguration firmware, build and modification instructions, analysis tools, and validation data are provided to support reproduction and adaptation to new experimental requirements.