Earth-Moon transfer with near-optimal lunar capture in the restricted four-body problem

In this paper, the low energy transfer (LET) from low Earth orbit to a permanent lunar orbit is investigated under the Sun-Earth-Moon-spacecraft restricted four-body problem (RFBP). Based on the near-optimal lunar capture, we propose an optimization method to construct the three-impulse Earth-Moon transfer in the RFBP. In the design process, a hybrid model is used to reduce the difficulty of the optimization problem. Compared with the Weak Stability Boundary transfer, the transfer orbit obtained has more chances to insert the spacecraft into low lunar orbit. Besides, compared with the patched-conic transfers, the LETs obtained can efficiently reduce the propellant costs, but the transfer durations apparently increase. Finally, the effect of solar gravitation on the transfer is analyzed.