Autonomous Magnetic Attitude Control of Resource-Constrained Femtosatellites

This paper advances the state-of-the-art Femtosatellite (Femtosat) technology by developing and implementing magnetic attitude control strategies for resource-constrained satellites. The proposed magnetic attitude control framework is designed for a 35 mm×35mm,13gFemtosat,whichintegratesmicro-electro-mechanicalsystems(MEMS)forattitude sensing using a 3-axis magnetometer and gyroscopes, along with small magnetic torquers and a Texas Instruments (TI) CC1310 ultra-low-power wireless microcontroller. The study aims to enable autonomous decision-making, allowing Femtosats to dynamically adapt to changing mission requirements, environmental conditions, and power limitations. The paper first establishes the Femtosat dynamics model, followed by numerical simulations for validation. Further, a control law is developed to stabilise the Femtosat, mitigating tumbling and enabling pointing. Various control strategies, including proportional-integral-derivative (PID) and bang-bang control, are implemented and evaluated for feasibility on the resource-limited TI CC1310 microcontroller. In addition, power management requirements are analysed to ensure compatibility with the constrained energy resources of the Femtosat. Finally, experimental validation is conducted using a small Helmholtz cage to demonstrate the effectiveness of the proposed single-axis magnetic attitude control strategies in real environmental conditions. The outcomes of the paper aim to pave the way for more effective and autonomous Femtosat operations, thereby expanding the capabilities of these miniaturised spacecraft in diverse space exploration scenarios and scientific endeavours.