Design and implementation of a real-time onboard system for a stratospheric balloon mission using commercial off-the-self components and a model-based approach

Stratospheric balloons have emerged as an affordable and flexible alternative to traditional spacecrafts as they are implemented using commercial off-the-shelf (COTS) equipment without following strict methodologies. HERCCULES is a stratospheric balloon mission that aims to characterize the convective heat and radiative environment in the stratosphere. The purpose of this article is to present the HERCCULES onboard software (OBSW) whose design and complexity is comparable to that of satellite systems, since it must control about sixty COTS equipment using a single Raspberry Pi 4B as onboard computer and ensure the real-time requirements. Compared to similar systems, novel contributions are presented as the OBSW is developed following modelbased and component-based approaches using the TASTE toolchain from the European Space Agency (ESA) for automatic code generation. Besides, the OBSW is verified and validated following the ESA standards and the results obtained demonstrate the suitability and efficiency of the solution and the selected methodologies.