Fly-by Approach and Guidance for Uncontrolled Rotating Satellite Capture

Fig. 1 V-bar, R-bar and Fly-by Approach Existing orbital transfer vehicles such as US Space Shuttles, Progress and Japanese H-IIA Transfer Vehicle (HTV) use a straight path approach to the International Space Station (ISS). The straight path approach has many advantages and is suitable for stable targets such as ISS and three-axis attitude-controlled satellites. However, for satellite capture missions, we cannot assume that the target satellite is in a stable attitude or that the docking or grasp point is on the straight path. We therefore developed a fly-by approach and capture method for uncontrolled satellite capture, in which a space robot approaches a target on a non-collision path subject to orbital mechanics and executes capturing task using its manipulator if everything goes well. This approach method can be used for arbitrary target positions and velocities in three-dimensional space. By choosing an appropriate initial position and velocity to utilize orbital mechanics, a space robot can approach a target position and velocity without any active trajectory control. This paper focuses on a fly-by approach method for uncontrolled rotating satellite capture considering collision avoidance between space robots and the target satellite, discusses the relative motion behavior during the fly-by approach, and develops planning and guidance algorithms for the fly-by approach.