Low-thrust rendezvous trajectory generation for multi-target active space debris removal using the RQ-Law

The problem of space debris must be addressed to avoid a cascading collision in the near future that would critically damage humanity's space assets and dependent terrestrial infrastructure. One method of meeting this challenge is to use a dedicated spacecraft to deorbit a series of prioritized debris. To avoid a large fuel requirement, electric spacecraft propulsion can be used, for which a multiple-rendezvous low-thrust trajectory is of interest. In this study, we develop such a trajectory for a predetermined subset of the Iridium 33 debris using a two-step procedure. First, the target rendezvous order is determined by using relevant distance metrics to approximate the transfer cost between debris objects. Next, the RQ-Law, a recently developed Lyapunov feedback control law for generating low-thrust rendezvous trajectories, is used to generate a trajectory that can take a spacecraft to each of the studied debris objects in the determined order. This method can be used to rapidly determine low-thrust multi-target multi-revolution rendezvous trajectories in the preliminary design stage for missions such as space debris removal and satellite servicing without requiring an initial guess.