Optimal low-thrust libration points rendez-vous in Earth-moon system

In this paper the minimum propellant optimal manoeuvres of space vehicles equipped with low-thrust propulsion installation near the libration points in the Earth-moon system are examined. The variational problem for determining the optimal laws of variation of the motion parameters, is a Lagrange type considering complete motion equations, and lead to a bilocal problem. The numerical integration of the extremals equations is performed with "shooting" method, the calculus being simplified using the approximate solutions in the case when Coriolis term is neglected (omega = 0) for establish the initial values of the Lagrange multipliers. On the basis of the optimal laws established in this manner, numerical applications are carried out.