Solar sails use the sun's energy to fly spacecraft, or "flight by light." It sounds like something out of a science fiction novel. In fact, it is, first being mentioned in Jules Verne's From Earth to the Moon in 1865. It's been used as a way for characters to travel through space in many other books and movies, including Tron in 1985. Today, solar sails are a reality, and readers learn how their technology works as well as how successful trials with solar sail apparatuses have been. Could light energy be the best way to move through space in the future? Readers find out for themselves.