Rocheworld

Rocheworld (first published in serial form in 1982; first book publication, under the title The Flight of the Dragonfly, 1984) is a science fiction novel by Robert Forward in which he uses a light sail propulsion system to set the crew on an interstellar mission. The spaceship and crew of 20 have to travel 5.9 light-years (ca. 34 trillion miles; ca. 56 trillion km) to the double planet that orbits Barnard's Star, which they call Rocheworld.