Safe path planning for free-floating space robot to approach noncooperative spacecraft

In order to eliminate plume impingement on the target satellite, a free-floating space robot (also known as a chaser), which has the advantage of executing on-orbit service, is always used. This paper develops a path planning method for a safe rendezvous of chaser with a noncooperative target satellite in orbital coordinates. Safety principles for rendezvous in terminal approaching phase are proposed. Grasp points on the target satellite are analyzed and classified into two categories, and a moving ellipse trajectory is adopted to approach a rotating and uncontrolled target satellite. This method guarantees that the chaser can successfully escape if unexpected error occurs or capture fails. The simulation results show that, with this novel autonomous rendezvous method, the chaser can approach the noncooperative target satellite along the designated trajectory in any quadrant of the orbital plane.