Designs of optimal free-return orbit for moon landing

The paper designs the transfer orbit of the lunar landing from the low earth orbit to the low moon orbit based on the patched-conic technique. The equations of orbital parameters are established by utilizing the conservation of moment of momentum. Considering the optimization of the consumption of energy and time, the paper constructs the corresponding optimization problems to the orbital parameters. At last, an example is given which illustrates the feasibility and advantage of the proposed approach.