A Solar Sail is a secondary form of propulsion used on most starships in the Known Universe . It is secondary to the main propulsion generator, the Ion Drive , and is used on most, if not all ships. It works by using the Radiation Pressure from stars to push the ultra thin mirros to high speeds, aswell as being able to generate power to general onboard usage.
Modern Solar sails are generally mounted on top of the starship, acting like cloth sails of old-world sailing ships. Many are coloured red to absorb the most radiation from sources. Solar Sails are some of the lowest cost forms of propulsion however are rarely used as a primary form without an ion drive.