http://minerva.union.edu/novinsc/phys123/Sails.html To the left is an example of a heliogyro sail craft with the sails themselves still rolled up in the outward vanes. The fact that the sail itself can stay rolled up until deployment makes the sail itself easier to launch. It does however require external propulsion to get it spinning for the sails to unfurl.

http://minerva.union.edu/novinsc/phys123/Sails.html

To the left is an example of a heliogyro sail craft with the sails themselves still rolled up in the outward vanes. The fact that the sail itself can stay rolled up until deployment makes the sail itself easier to launch. It does however require external propulsion to get it spinning for the sails to unfurl.