Interplanetary mission design for spinning solar sails utilizing active shape control of sail membranes **

Performance of solar sails largely depends on their attitude motion. Thrust vector of a solar sail is determined by its relative attitude to the Sun. Meanwhile, there exist some requirements on its attitude, for example, to secure enough solar power and ground communication. Therefore, conventional solar sail missions have strong constraints on attitude motion. This is because conventional solar sails assume flat sail membranes to avoid some unexpected deformation. This assumption leads to the fact that the geometry of the spacecraft is limited within two dimensions. This paper introduces a mission design scheme for spinning solar sails by actively controlling the shape of the sail membranes. The active shape control extends solar sails to three-dimensional structures, and hence the two-dimensional constraints can be removed.