Method of Rapprochement of a Tether System with an Uncontrolled Space Object

Abstract: The problem of the approach of a tether system with an uncontrolled space object (space debris, cargo, etc.) in an almost circular near-Earth orbit is considered. An approach method is proposed that consists of the preliminary transfer of an active spacecraft to an orbit whose parameters are selected so that in its relative motion it moves along a trajectory close to an ellipse relative to a passive space object. Next, the tether system is deployed with a gripper device in the radial direction, and the length of the tether approximately corresponds to half of the small semiaxis of the ellipse of relative motion. After the end of the tether’s deployment, the entire system continues to rotate around the passive space object. In this case, there is a possibility of additional correction of the length of the tether in order to reduce the minimum distance between the gripper device and the load. To control the movement of an active spacecraft, jet engines are used, the components of the continuous thrust of which are directed along the transversal and binormal orbits. The results of end-to-end modeling in a geocentric fixed coordinate system of the considered stages of pointing the gripper device at a passive space object in the spatial case are presented, including an assessment of the impact of the gripper process on the subsequent movement of the entire system with cargo during its transportation.