Constructing cislunar infrastructure on distant retrograde orbit by low-thrust transfer

Distant retrograde orbits (DROs) have good potential to work as the parking orbits of Earth-Moon transportation stations for their natural stability. This paper proposes a systematic control procedure based on the Gauss pseudospectral method (GPM) and tangential thrust strategy for low-thrust transfer in a scenario where spacecraft travel between the Earth, the Moon, and DROs. To optimize mission performance, an improved strategy is proposed to reduce the fuel consumption while avoiding excessively prolonged transfer durations. Based on the numerical results, we innovatively propose an analytical shape-based expression of the transfer trajectory from Low Moon Orbits (LMOs) to DROs, which could provide a reliable initial guess for numerical optimization. Furthermore, the effect of the Moon's inclination to the Earth's equator which varies between 18.3° and 28.6° is thoroughly investigated. The results show that the influence of the Moon's inclination to the Earth's equator is non-negligible. Additionally, the distribution of different conditions, including departure and arrival points as well as thrust acceleration limits, is presented, which could provide a reliable reference for practical missions.