A large membrane space structure deployed and spanned by centrifugal force
owing to the spin motion, contains a hub located at a central portion
thereof and a sail including a plurality of petals attached to the hub by
supports. Each of the petals has regions symmetrical to an imaginary
center line passing through the center of the hub. Membranes are spanned
on the regions. Each of the membranes is divided into parts of suitable
shapes, and adjacent membranes are discretely connected to each other by
bridge belts to suppress the residual crease strain. The petals are
symmetric with respect to the center of the hub. Deployment force is
provided in the circumferential direction by the introduction of imaginary
tension lines. The petals may be connected to each other to help
deployment.
