Multi-objective planning of a multiple geostationary spacecraft refuelling mission

The multi-objective optimization of multiple geostationary spacecraft refuelling is investigated in this article. A servicing spacecraft (SSc) and a propellant depot (PD), both parked initially in geostationary Earth orbit (GEO), are utilized to refuel multiple GEO targets of known propellant demand. The capacitated SSc is expected to rendezvous with fuel-deficient GEO targets or the PD for the purpose of refuelling or getting refuelled. The multiple geostationary spacecraft refuelling problem is treated as a multi-variable combinatorial optimization problem with the principal objective of minimizing the propellant consumption and the mission duration. A two-level optimization model is built, and the design variables are the refuelling order X, the refuelling time T and the binary decision variable S. The non-dominated sorting genetic algorithm is employed to solve the up-level optimization problem. For the low-level optimization, an exact algorithm is proposed. Finally, numerical simulations are presented to illustrate the effectiveness and validity of the proposed approach.