On-orbit capture with flexible tether–net system

A new concept using flexible tether–net system to perform on-orbit capture is presented in this paper. As a promising on-orbit capture strategy, the tether–net system has many exciting advantages by contrast with the existing orbital capture system. However, under the disturbance of orbital dynamics an attitude libration, which leads to a capture error, will be presented when the capture net is ejected towards the target aiming at investigating the relationship between the capture error and initial capture conditions, the governing equations of the tether–net system in orbital frame is developed by applying Lagrange equations. In order to optimize capture operation, the in-plane capture constraints are studied by numerical simulations with an effort to damp the in-plane libration and compensate the capture error, the control scheme based on tether tension is investigated firstly, after that an integrated control scheme is proposed by introduced the thrusters into the system, the nonlinear closed-loop dynamics is linearized by feedforward strategy, the simulation results show that feedforward controller is effective for in-plane libration damping and enable the capture net to track an expected trajectory.