Colloquium: Thomas Daniël van den Oever (A&S)
27 augustus 2018 13:00 - Locatie: Lecture room D, Faculty of Aerospace Engineering, Kluyverweg 1, Delft.
Solar-sail transfers to Earth-Moon L2-displaced vertical Lyapunov orbits
This work presents the design of solar-sail transfer trajectories to a constellation of two spacecraft in displaced vertical Lyapunov orbits at the L2 point of the Earth-Moon system. The constellation provides continuous coverage of the Aitken basin and the lunar South Pole. Initial guesses for the transfers are generated using reverse time propagations of the dynamics, where the control is provided by an optimal steering law. These guesses are subsequently used to initialize a 12th-order Gauss-Lobatto collocation method. The minimum altitude is constrained, as well as the maximum rotation rate of the solar sail. Sets of trajectories for both spacecraft with identical launch conditions are sought, such that the constellation can be initiated using a single Soyuz launch. Subsequently, both spacecraft are able to reach their respective target orbits within 67.89 days. This research demonstrates that solar-sail transfer trajectories are a feasible option for future missions in the Earth-Moon system.