Motion Planning Strategies for Safety Procedure of Multisatellite Formation-Flying Systems

The concept of multiple satellites in formation brings a significant advancement in enhancing the performance of single-pass synthetic aperture radar interferometry. Maintaining a constant baseline is vital to enhance interferometric acquisition and poses significant challenges to the safety conditions of the vehicles. This study presents a motion planning strategy specifically designed to address safety procedures in the event of anomalous onboard conditions for a fast reconfiguration to a safe mode. The research examines two approaches: the linear quadratic regulator (LQR) and the model predictive control (MPC). It investigates the capability of different controllers for fast formation reconfiguration in terms of minimum propellant consumption and passive safety. We demonstrate that the MPC controller can autonomously plan and implement an optimal maneuver in less than one orbital period. On the other hand, the LQR can benefit from an automatic tuning of the gains to track an optimal reference trajectory. As a practical implication, this research provides solutions to maintaining a safe formation with constant baselines, proposing different control schemes.