Global magnetic attitude control of spacecraft in the presence of gravity gradient

The problem of Earth-pointing attitude control for a spacecraft with magnetic actuators is addressed and a novel approach to the problem is proposed, which guarantees almost global closed loop stability of the desired relative attitude equilibrium for the spacecraft. Precisely, a proportional derivative (PD)-like state feedback control law is employed together with a suitable adaptation mechanism for the controller gain. Simulation results are presented, which illustrate the performance of the proposed control law     

Star identification algorithms: novel approach & comparison study

A novel approach to the problem of star identification for spacecraft attitude determination based on data provided by a star camera is proposed. The algorithm is based on pattern matching ideas and provides improved reliability with respect to similar methods available in the literature. The achievable performance is demonstrated via a comparison study with two published algorithms