In this work, we develop a new method to design energy minimum low-thrust
missions (L2-minimization). In the Circular Restricted Three Body Problem, the
knowledge of invariant manifolds helps us initialize an indirect method solving
a transfer mission between periodic Lyapunov orbits. Indeed, using the PMP, the
optimal control problem is solved using Newton-like algorithms finding the zero
of a shooting function. To compute a Lyapunov to Lyapunov mission, we first
compute an admissible trajectory using a heteroclinic orbit between the two
periodic orbits. It is then used to initialize a multiple shooting method in
order to release the constraint. We finally optimize the terminal points on the
periodic orbits. Moreover, we use continuation methods on position and on
thrust, in order to gain robustness. A more general Halo to Halo mission, with
different energies, is computed in the last section without heteroclinic orbits
but using invariant manifolds to initialize shooting methods with a similar
approach