Thruster Rotation Angle Control During Contactless Removal of Space Debris Objects

The chapter deals with the issues of contactless removal of space debris objects, the orbit of which is changed by a high-velocity ion beam injected from the service spacecraft moving in the immediate vicinity of the debris object. We consider the issues of controlling the angles of rotation of electric propulsion thrusters to implement changes in the thrust components of electric propulsion system in the longitudinal and transverse directions required during the debris object transportation. Arrangement of thrusters is proposed taking into account the location of solar arrays and the difference in permissible angles of thruster deflection in different planes. We analyze possible options for the thruster rotation angles to provide the required values of the thrust projection onto the axes of the spacecraft-associated coordinate system. We propose an algorithm for controlling the thruster rotation angles to implement the required thrust projection values, which allows to control the sign of the momentum relative to the spacecraft longitudinal axis depending on the accumulated total momentum. The results of modeling the electric propulsion system operation during the space debris objects transportation are presented.