On-orbit refueling of sun-synchronous-orbit (SSO) satellite clusters requires effective deployment of fuel stations (FSs). To this end, this paper investigates the deployment optimization problem of fuel stations for SSO clusters by considering orbital geometry, satellite-to-station assignment, and refueling mission feasibility. A \(J_2\)-aware optimization framework is proposed, in which a particle swarm optimizer searches for optimal fuel-station orbital parameters and satellite assignments. For each candidate deployment, a deterministic mission evaluator is employed to estimate natural alignment opportunities, transfer requirements, and fuel consumption. The proposed approach considers th... More >