A MODIFIED UPE METHOD TO DESIGN TWO-IMPULSE EARTH-MOON TRANSFERS IN A FOUR-BODY MODEL

A hybrid unscented parameter estimation algorithm is proposed for the efficient design of two-impulse Earth-Moon transfers in the planar bicircular restricted four-body model. This scheme is an extension of unscented Kalman filter parameter estimation that accommodates Newton's method. The original transfer problem is firstly converted to a new state-space representation and unscented parameter estimation is utilized in the initial iterations to take advantage of its wide-range convergence ability. Once close the final solution, the algorithm switches to the Newton method, which boosts convergence and accuracy. Numerical experiments show that the proposed method presents a good balance between convergence domain and convergence rate.