NASA is to send a solar sail demonstrator into orbit next week, and there is a good chance that the sail, measuring 860 square feet (80 square meters), will be visible from Earth. Advanced Composite Solar Sail System (click to enlarge) Pic: NASA The primary goal of the Advanced Composite Solar Sail System (ACS3) mission is to demonstrate the deployment of a new composite boom made from flexible polymer and carbon fiber materials. Despite being stiffer than previous designs, the tube-shaped boom ...