Adaptive torque equilibrium attitude guidance for rapid deorbit of space debris by aerodynamic drag considering model uncertainty

Abstract Currently, considerable research is directed toward active debris removal (ADR) in space, especially by small, cost-effective satellites. However, a drawback to effective ADR missions has been that they use thrusters to move from a high altitude for reentry, which consumes a great deal of fuel. Thus, the propulsion system for these satellites is quite large, so designing the propulsion system for a small satellite is quite difficult. This paper proposes a new guidance design based on the altitude-dependent mean torque equilibrium attitude (TEA) and centered on determining the equilibrium point in a satellite’s attitude dynamics with respect to aerodynamic and gravity gradient torques. To correct guidance errors, the adaptive TEA guidance technique learns the actuator inputs during one orbital revolution. The controller is designed to guarantee robustness against disturbances and modeling uncertainties. Finally, the proposed adaptive guidance system and the robust controller’s effectiveness are demonstrated through numerical simulations to enhance the feasibility of an ADR mission.