Mission planning optimization for multiple geosynchronous satellites refueling

The scheduling problem of multiple geosynchronous satellites refueling mission with a servicing satellite and a fuel station is studied in this paper. In the proposed mission scenario, a number of geosynchronous satellites require a specified weight of fuel to be delivered. The servicing satellite and the fuel station are initially parked in the geosynchronous Earth orbit (GEO). The capacitated servicing satellite is expected to visit and refuel these fuel-deficient GEO targets with the fuel received from the fuel station. In general, the fuel station will refuel the servicing satellite more than once. The refueling order and binary decision variable are used as design variables, whereas the total fuel consumed by orbital maneuvers is used as a design objective. A one-level optimization model and a two-level optimization model are formulated to find the optimal refueling order and decision variable. Genetic algorithm (GA) is employed to address the one-level optimization problem. For the two-level optimization problem, the up-level GA that optimizes the refueling order is combined with the low-level random search that can quickly locate the near-optimal binary decision variable. Finally, the proposed methods are applied to numerical test cases to demonstrate that they are valid for mission planning optimization for multiple GEO targets refueling.