Robotic Satellite Self-Assembly via Inverted Serial Kinematics

The desire to establish in-space logistics systems has led to the development of new methods for satellite life extension. These methods include on-orbit refueling, propulsion system upgrades, and module swapping or coupling using highly mobile servicing satellites. This paper outlines a methodology to execute a sequence of actions for a smart satellite equipped with a robotic manipulator to autonomously assemble to a passive module, creating a more capable satellite. This paper showcases a demonstration of this methodology at an Air Force Research Laboratory (AFRL) ground-based test facility, the Robotic Orbital Control (ROC) lab. The testbed at this facility includes two hexagonal float craft suspended by air bearings on top of a granite table, with the ability to move without friction. These modular robotic craft are equipped with docking adapters and a robotic arm. A layered and modular software architecture handles autonomy and control, with communication within the system occurring via Robot Operating System 2 (ROS2). Ground truth data collected using a motion capture system (MCS) verifies successful completion of the planned trajectories and assembly events.