Sliding Mode Control Strategies for Rendezvous and Docking Maneuvers

RENDEZVOUS and docking maneuvers represent operational key technologies in many spacecraft missions and consist of a series of orbital maneuvers and controlled trajectories during which an active spacecraft (chaser) tries to capture a passive target vehicle. The goal of the mission is that the chaser vehicle has to safely and efficiently approach, up to few centimeters (surface-to-surface), the target vehicle, satisfying the strict requirements of docking in terms of relative position, speed, and with zero angular velocities. Once the target is reached, the chaser has to remain stationary until the hold mechanism captures and docks the target vehicle. The faced problem requires control of both the relative position and the relative attitude of the vehicles.