This paper considers the problem of motion synchronization of free flying robotic spacecraft and serviceable floating objects in space. The synchronization maneuvers are conducted in two phases: The first one aimed at maintaining a constant relative separation using thrusters, with the relative position vector directed along the receiving port of the target. The second maneuver then re-orients the pursuer vehicle using passive actuation mechanisms so as to direct the robotic arm along the

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... ve position vector. This is achieved by constructing a desired attitude, and the control law seeks to zero the errors between the current and desired attitude parameters. Disturbance torque due to gravity gradient and other unknown disturbances is accounted for via an adaptive disturbance observer formulation. The stability of the control law is demonstrated via a Lyapunov analysis and extensive numerical simulations demonstrate the efficacy of this control formulation. p