Low-Thrust Reconfiguration of Satellite Constellations Using the Mapping Method

For responsive observation missions, characterized by significant variations in the ground locations of interest, a satellite constellation may have difficulty performing timely overflights of these ground targets. Performing reconfiguration maneuvers of the constellation is a possible option. For satellite constellations equipped with low-thrust propulsion systems, a burn–coast–burn three-phase maneuver strategy was studied to achieve a balanced solution between responsiveness and fuel consumption. In this study, we modify the existing three-phase strategy to a five-phase strategy by adding two coasting phases on the initial and final orbits, which increases the number of control variables and therefore admits better solutions. However, the increase in the number of control variables results in complexity in finding the optimal control variables compared with the original three-phase method. To simplify the problem, the mapping method is employed to reduce the dimensionality of the optimal control problem by two, resulting in an optimal control problem with the same complexity as the original three-phase problem. Finally, a comprehensive comparison involving three scenarios is performed with the three-phase maneuver strategy. The simulation results show that the single-satellite overflight scheme derived from this approach forms an enhanced Pareto front in terms of both velocity change and overflight time objectives; hence, the constellation reconfiguration scheme achieves less fuel consumption and a shorter maneuver reconfiguration time.