Differential-drag-based roto-translational control for propellant-less spacecraft

This paper proposes a novel technique to perform propellant-free chaser-target spacecraft relative maneuvers while simultaneously stabilizing the chaser's attitude with respect to the local vertical local horizontal coordinate system centered at its body center of mass. The control forces required for relative maneuvers at low Earth orbits can be generated by varying the relative aerodynamic drag via maneuverable sails placed in the back-end of the spacecraft. At the same time, aerodynamic torques resulting from the displacement of the centers of pressure of the sails can stabilize the orientation of the spacecraft. In this work, the target vehicle is assumed to maneuver an identical sail in a cooperative fashion and will be centered and attitude-stabilized in its local vertical local horizontal coordinate system. The proposed approach is based on the idea of virtual thrusters, emulating the sail's center of pressure offset in the controller. Several test cases are presented for various existing spacecraft, demonstrating successful propellant-less roto-translational control of the chaser spacecraft.