A report presents a theoretical approach to designing a low-energy transfer of a spacecraft from an orbit around the Earth to ballistic capture into an orbit around the Moon. The approach is based partly on the one presented in “Low-Energy Interplanetary Transfers Using Lagrangian Points” (NPO-20377), NASA Tech Briefs, Vol. 23, No. 11 (November 1999), page 22. The approach involves consideration of the stable and unstable manifolds of the periodic orbits around the Lagrangian points L1 and L2 of the Sun/Earth and Earth/Moon systems. (The Lagrangian points are five points, located in the orbital plane of two massive bodies, where a much less massive body can remain in equilibrium relative to the massive bodies.)

This work was done by Martin Lo, Jerrold Marsden, Wang S. Koon, and Shane Ross of Caltech for NASA’s Jet Propulsion Laboratory. To obtain a copy of the report, “Low Energy Lunar Transfer and Capture,” access the Technical Support Package (TSP) free online at www.nasatech.com/tsp under the Mechanics category. NPO-20936