Editing Trans-lunar injection (section)

=== Restricted circular three body (RC3B) ===
More realistically, however, the spacecraft is subject to [[Gravitational force|gravitational forces]] from many bodies.  Gravitation from Earth and Moon dominate the spacecraft's acceleration, and since the spacecraft's own mass is negligible in comparison, the spacecraft's trajectory may be better approximated as a [[Euler's three-body problem|restricted three-body problem]].  This model is a closer approximation but lacks an analytic solution,<ref>[[Henri Poincaré]], ''Les Méthodes Nouvelles de Mécanique Céleste'', Paris, Gauthier-Villars et fils, 1892-99.</ref> requiring numerical calculation.<ref>[[Victor Szebehely]], ''Theory of Orbits, The Restricted Problem of Three Bodies'', Yale University, Academic Press, 1967.</ref>