In the mission of approaching to a disabled tumbling target,the space will be divided into the safe zone and the unsafe zone because of the nutation of the target. During the chaser's flight in the safe zone of the target,the collision possibility between the target and the chaser should be determined to avoid the collision accident. To solve this problem,the region judgment method is used to transform the task into the position relation determination problem between the safe zone of the target and the traj...