Safety-Critical Composite Attitude Control for Vleo Satellites under Composite Disturbances

Secure attitude maneuvers of spacecraft in Very Low Earth Orbit (VLEO) are affected by composite disturbances, including center of mass variations and atmospheric drag. For systems subject to mandatory constraints, such disturbances can compromise attitude tracking precision and potentially lead to safety violations. To address this challenge, a maneuvering control scheme based on disturbance observation and barrier function is proposed. First, a coupled spacecraft attitude dynamics model is developed to reveal the influence of composite disturbances. Second, a composite controller incorporating a nonlinear disturbance observer and a state-dependent barrier function is designed to perform real-time compensation of these disturbances while ensuring constraints compliance. The effectiveness and robustness of the proposed approach are validated through numerical simulations.