Deployment and Retraction Mechanisms for Spinning Solar Sail Membrane

The deployment and retraction mechanisms for two-dimensional deployable membrane for spinning solar sail are proposed in this paper using wrapping fold for polygonal membrane with tensile forces. The fold and deployment of large-scale membrane sails are significant to realize the solar sails. The spinning solar sail is one of the concepts, which uses the centrifugal force to deploy the membrane. The structural and dynamic properties of the spinning solar sail are determined by the folding pattern and deployment mechanisms. The rotationally skew fold, which is proposed by authors, is one of the concepts for the solar sail membrane. However, the manufacturing and the folding of the rotationally skew fold are quite difficult due to the double corrugation properties. Therefore, we have developed folding and retraction mechanisms using wrapping fold with tensile forces by modifying the rotationally skew fold pattern with spiral fold. Experiments with the conceptual folding mechanisms for two-dimensional deployable membrane are demonstrated, and finally, the by optimizing the distribution of tensile forces and controlling the hinge deformation for the initial fold, the membrane have been successfully folded.