High-Speed Docking and Applications for Small Spacecraft

Recent advancements in small satellite technology have enabled the development of various commercial and scientific platforms. Many of these have been conceived and designed around the concept of formation flying, implying cooperation between different vehicles. A critical step in constructing such systems involves docking the different agents that compose the swarm. It is, therefore, crucial to take steps to improve the docking ability of small satellites for a wide variety of operating conditions. Furthermore, the ability to dock satellites is also needed for other vital applications such as on-orbit servicing of non-cooperative satellites, in-space assembly of larger structures, reconfigurable satellites and stations, and other autonomous proximity operations. Existing docking systems implemented in space operate under an operational requirement of the relative velocity between the two docking spacecraft being less than 1 m/s, typically around 50 cm/s. These systems require at least one of the two spacecraft to perform a rendezvous operation to reduce the relative velocity between the two docking satellites. However, situations exist where a rendezvous operation is either not feasible or efficient, and only an interception is possible. This may apply in the case of non-cooperative spacecraft moving at very high speeds or space debris. This calls for the requirement of docking adapters and supporting systems that enable docking at high relative velocities. This paper explores the different docking adapter systems that may enable high speed docking. We discuss systems that use either inflatables, electromagnetic systems, flux pinning using superconductors, and metamaterials such as shape memory alloys and shape morphing alloys as docking adapters and the supporting system requirements for each docking adapter system. Inflatables act as dampers to reduce the kinetic energy of the incoming non-cooperative spacecraft, while metamaterials use shape morphing to conform to the shape of the eternal features of the incoming spacecraft. All these systems require unique sensors and actuator suites to operate with different levels of Technology Readiness Level (TRL). We aim to perform 3D Physics simulations and analytical calculations such as feasibility calculations and detailed trade studies between different methods of high-speed docking. Prototypes will be constructed for testing in simulated settings in the laboratory, based on the 3D simulation findings and analytical calculations. To validate the designs, ground-based equipment such as 6-DOF robotic arms that imitate the spacecraft's ADC systems and air tables that emulate the frictionless environment of space will be used. Finally, we plan to propose a CubeSat mission concept based on the findings of the trade study that will deploy and demonstrate the technology in orbit.