Efficient high-accuracy north-south station-keeping strategy for geostationary satellites

Station-keeping (SK) is indispensable in actual geostationary (GEO) satellite missions. Due to the luni-solar gravity perturbations, the inclination of a GEO satellite suffers the issues of secular drift and long-period oscillation. Current north-south (NS) SK strategies maintain the GEO satellite's orbit with high accuracy but low fuel efficiency. In this work, an efficient high-accuracy NS-SK strategy is developed for the GEO satellites. First, an averaging method is employed to decrease the accumulation of the secular drift within a one-solar-day SK cycle, while the long-period oscillation caused by the solar gravity is damped to further improve the orbital accuracy using the impulse and finite-thrust propulsions. Second, we contribute a fuel-optimal cycle that reduces the fuel consumption and a fixed-interval cycle that executes SK control in fixed time interval every day to further enhance the proposed NS-SK strategy. Numerical simulations show that the improved strategy can achieve high-accuracy NS-SK with little fuel consumption. Moreover, results also demonstrate that the fixed-interval cycle can reach higher NS-SK accuracy while consuming less fuel.