Abstract:

In case of a failure on a Hohmann-base translunar trajectory, a reconfiguration of the trajectory that utilizes the three body dynamics of the interior realm of Earth-moon system is proposed. The stable and unstable manifold of a periodic orbit around L1 point extended toward the Earth side have homoclinic intersections. In the proposed method, after detection of a failure on the nominal trajectory, the trajectory is modified by small maneuvers so that the spacecraft can be kicked back by the moon and transferred to the unstable manifold. Then the spacecraft is returned back to the moon side through the intersection with the corresponding stable manifold on the Earth side. The periodic orbit is again used as a parking orbit so that the amount of delta-v at the moon orbit insertion can be reduced. Since the required amounts of delta-v at each individual maneuver are small throughout the reconfigured trajectory, it can serve as a solution for a backup trajectory in case of amain engine failure. Also since the operability in interior realm is good and the trajectory takes time, it can give a great chance for diagnosis and repair of the failure before arriving at the moon.