AbstractThis paper investigates the attitude tracking control problem for rigid spacecraft with inertia uncertainties and external perturbations. Spacecraft attitude dynamics and kinematics are initially converted into Lagrange-like model and formulated as a state-space form described by the modified Rodrigues parameters (MRPs). Robust controllers contain two parts and use geometric homogeneity, integral sliding mode (ISM) technique, and adaptive laws. One part proposes a class of feedback controllers to accomplish finite-time stabilization of the second order dynamics without the lumped uncertainties. The other part rejects bounded uncertainties based on ISM associated with adaptive laws. Moreover, a rigorous proof of finite-time convergence is developed. The proposed control laws provide finite-time convergence, robustness, and faster and higher control precision, and these algorithms require no information about inertia uncertainties and external disturbances, which cannot be obtained in practical syst...