Robotic manipulators for in-orbit servicing and active debris removal: Review and comparison

Due to the growing threat from space debris and the accelerating increase in the number of active satellites, Active Debris Removal (ADR) and In-Orbit Servicing (IOS) missions are currently being developed. A robotic manipulator mounted on a servicing satellite will enable precise grasping of a target object and is needed to perform complex servicing tasks. This paper presents a comprehensive review of robotic manipulators developed for ADR and IOS missions. This review includes the manipulators that have already been used in orbital missions, those developed in the past for missions that were cancelled, technology demonstrators, and the manipulators currently in development for planned missions. The review includes the following manipulators: the Shuttle Remote Manipulator System, the manipulator developed for the ETS-VII mission, the Orbital Express Demonstration Manipulator System, the manipulator developed for the DEOS mission, the CAESAR, the LARAD, the VISPA, the WMS 1 Lemur, the TITAN, the FREND, the STAARK, and the TINA manipulators. Small manipulators designed for nanosatellites are also reviewed. Basic parameters of manipulators, such as the number of degrees of freedom, mass, and length, are compared. The Denavit-Hartenberg parameters and kinematic structures of the selected manipulators are presented. The paper includes a discussion of specific design features, such as the manipulator joint design. Finally, recent trends and future prospects are explored.