  We extend to the spatial case a technique of integration of the close
encounters formulated by Tullio Levi-Civita for the planar restricted
three-body problem. We consider the Hamiltonian introduced in the
Kustaanheimo-Stiefel regularization and construct a complete integral of the
related Hamilton-Jacobi equation by means of a series convergent in a
neighbourhood of the collisions with the primary or secondary body.
