Space travel[1]:69[2]:209-210[3]:511-512 or space flight[2]:200-201[4][5]:2103-2105 is a major classic theme in science fiction.[4]
The Visual Encyclopedia of Science Fiction lists the following methods of spacecraft propulsion: anti-gravity, atomic (nuclear), bloater,[lower-alpha 1] cannon one-shot[lower-alpha 2], Dean, FTL, hyperspace, interialess, ion, photon, plasma, ram-jet, r. force[lower-alpha 3], solar sail, spindizzy and torchship. Many but not all are based on real scientific theories.[1]:8, 69-77