STATIONKEEPING METHOD FOR LIBRATION POINT TRAJECTORIES

Three-dimensional orbits in the vicinity of the interior libration point (L1) of the Sun-Earth/Moon barycenter system are currently being considered for use with a number of missions planned for the 1990s. Since such libration point trajectories are, in general, unstable, spacecraft moving on these paths must use some form of trajectory control to remain close to their nominal orbit. The primary goal of this effort is the development of a stationkeeping strategy applicable to such trajectories. A method is presented that uses maneuvers executed (impulsively) at discrete time intervals. The analysis includes some investigation of a number of the problem parameters that affect the overall maneuver costs. Simulations are designed to provide representative station-keeping costs for a spacecraft moving in a libration point trajectory, and preliminary results are summarized.