Optimal Station Keeping for XIPS Thrusters in Failure Mode under Eclipse Constraints

Abstract

The objective of this paper is to minimize fuel consumption needed for geostationary Earth orbit station keeping by Xenon Ion Propulsion System (XIPS) thrusters in failure mode under eclipse constraints. Two diagonal XIPS thruster pairs, each pair consisting of one north thruster and one south thruster, are mounted on the antinadir face of the satellite. In failure mode, only one diagonal thruster pair fires. The original failure-mode station-keeping strategy without consideration of the eclipse constraints fires the remaining diagonal thrusters a second time with equal duration in the vicinity of ∼0° or 180° right ascensions (RA), in addition to a first time in the vicinity of ∼90 and 270°RA, which also results in the problem of excessive fuel consumption. The eclipse constraints are considered in this paper and the feasible firing location for station keeping during eclipse time is established. A optimal failure-mode station-keeping strategy under eclipse constraints is presented with the firing locations and durations of one diagonal thruster pair as design variables. The optimal station-keeping model is built and applied for maintaining a geostationary satellite within a predefined space box. Precise orbital simulation results show that the proposed optimal failure-mode station-keeping strategy can both save fuel and satisfy eclipse constraints.