Space travel: 69 : 209–210 : 511–512 or space flight: 200–201  (and less often, starfaring or star voyaging: 217, 220 ) is a major classic theme in science fiction, one that has generally captured the attention of the public and is commonly associated with the typical image of a science fiction plot. Space travel, whether interplanetary or interstellar, is usually carried out through space ships, and methods of spacecraft propulsion described in various works range from scientifically plausible to totally fictitious.: 8, 69–77 While some writers focus on the realistic, scientific and educational aspects of space travel, for others, that concept can be seen as a metaphor for freedom, one of whose aspects is to "free mankind from the prison of the solar system". Although the concept of a rocket, popularized by the science fiction works, has been described as one of the icons of the 20th century,: 744 according to The Encyclopedia of Science Fiction, "The means by which space flight has been achieved in sf – its many and various spaceships – have always been of secondary importance to the mythical impact of the theme".
One of the classic, defining tropes of the science fiction genre is that the action takes place in space, either on board of a spaceship or on another planet.: 511–512  Early works of science fiction, called "proto SF", such as novels by 17th century writers Francis Godwin and Cyrano de Bergerac, or astronomer Johannes Kepler, include "lunar romances", where much of the action takes place on the Moon.[b] Science fiction critic George Slusser also pointed to Christopher Marlowe's Doctor Faustus (1604), in which the main character is able to see the entire earth from high above, and noted the connections of space travel to the earlier dreams of flying and air travel, seen as far back as the writings of Plato and Socrates.: 742 In such a grand view, the significance of space travel and inventions such as various forms of "star drive", can be seen as metaphors for freedom, one of whose aspects is to "free mankind from the prison of the solar system".
Over the coming centuries, while science fiction addressed many aspects of futuristic science aside from space travel, that particular concept proved to be the most influential and impactful in the mind of both the general public and the genre writers and readers, evoking their sense of wonder.: 69  Most works were mainly intended to amuse the readers, but a small number, often written by authors who were also scholars or had a scholarly background, intended to educate its readers about various aspects of space-related science, such as various concepts related to astronomy; this trend was encouraged among others by the influential American editor Hugo Gernsback, who referred to this approach as "sugar-coated science" and "scientification".: 70 Science fiction magazines, including Gernsback's own Science Wonder Stories, alongside works of pure fiction, published articles popularizing scientific concepts, including early studies and discussions on the feasibility of space travel; and many science fiction writers were involved in publishing non-fiction works on space travel, such as articles by Willy Ley or David Lasser's book, The Conquest of Space (1931).: 71 : 743
From the late 19th and early 20th centuries onward there was a visible distinction between more "realistic" and scientific fiction (which later would evolve into hard sf), whose writers, often scientists like Konstantin Tsiolkovsky and Max Valier, focused on the more plausible concept of interplanetary travel (to the Moon or Mars), whereas the more grandiose but less grounded in realism were the stories of "escape from Earth into a Universe filled with worlds", which gave rise the genre of space opera, pioneered by E. E. Smith,[c] popularized by the televisions series Star Trek that debuted in 1966.: 743  This trend continues to the present day, with some works focusing on "the myth of space flight"[d], others are centered on "realistic examination of space flight"[e]; the difference can be also described as that between the writers' concern on the "imaginative horizons rather than hardware". The success of the 20th century space program, such as the Apollo 11 Moon landing, was often described as "science fiction come true", and it has also served to further "demystify" the concept of space travel within the solar system, as from that point onward, the writers who wanted to focus on the "myth of space travel" were increasingly likely to do so through the concept of interstellar travel. While the theme of space travel is seen as one of the very optimistic in general,: 511–512 some revaluatory stories, often more pessimistic and disillusioned, juxtapose both of those trends, contrasting the romantic myth of space travel with a more down-to-earth reality.[f] George Slusser suggested that "science fiction travel since World War II has mirrored the United States space program: anticipation in the 1950s and early 1960s, euphoria into the 1970s, modulating into skepticism and gradual withdrawal since the 1980s.": 743
On the screen the French movie 1902 A Trip to the Moon, by Georges Méliès, also described as the first science fiction film, linked special effects to the depictions of spaceflight.: 744  Together with other early movies such as Woman in the Moon (1929), Thing to Come (1936) they contributed to the early recognition of the concept of the rocket as the iconic and primary means of space travel, decades before the space program begun in earnest.: 744 Later milestones in film and television include the Star Trek series and movies, and the 2001: A Space Odyssey film by Stanley Kubrick (1968), which visually advanced the concept of space travel, allowing it to evolve away from the simplistic rocket towards that of a more complex space ship.: 744
Generic terms for engines enabling spacecraft propulsion in science fiction include those of a space drive and star drive.[g]: 198, 216 In 1977 The Visual Encyclopedia of Science Fiction listed the following methods of space travel: anti-gravity,[h] atomic (nuclear), bloater,[i] cannon one-shot[j], Dean,[k] faster-than-light (FTL), hyperspace,[l] inertialess,[m]: 75 ion,[n] photon, plasma, ram-jet,[o] R. force[p], solar sail,[q] spindizzy[r] and torchship.[s]: 8, 69–77 The 2007 Brave New Words: The Oxford Dictionary of Science Fiction listed the following vocabulary related to the concept of a space drive: gravity drive,[t] hyperdrive,[u] ion drive, jump drive,[v] overdrive, ramscoop (a synonym of a ram-jet), reaction drive,[w] stargate,[x] ultradrive, warp drive[y] and the torchdrive.: 94, 141, 142, 253 Several of those terms are entirely fictitious or based on rubber science, while others are based on real scientific theories.: 8, 69–77 : 142 Many fictious ways or travelling through space, in particular, faster than light travel, tend to go against our current understanding of physics, in particular, the theory of relativity.: 68–69 Some works can sport numerous alternative star drives; for example the Star Trek universe, in addition to its iconic warp drive, has introduced concepts such as transwarp, slipstream and the spore drive, among others.
Many writers, particularly of early science fiction, did not address the method of travel in much detail, and many works of the "proto SF" era had to contend with their authors living in the time where knowledge about the "space" was very limited — in fact, many early works did not even consider the concept of vacuum and instead assumed that atmosphere of sorts, composed of air or aether, continues indefinitely.[z] Highly influential in popularizing the "science" part of the science fiction was the 19th-century French writer Jules Verne, whose method of space travel in his 1865 novel, From the Earth to the Moon (and its sequel, Around the Moon), was explained mathematically, and whose vehicle — the gun-launched space capsule — was described as the first such vehicle to be "scientifically conceived" in fiction.[aa]: 69 : 743 Percy Greg's Across the Zodiac (1880) featured a space ship with a small garden, an early prediction of hydroponics.: 69 Another writer who attempted to merge concrete scientific ideas with science fiction prose was the turn of the century Russian writer and scientist, Konstantin Tsiolkovsky, known for popularizing the concept of rocketry.[ab] George Mann pointed to works such as Robert A. Heinlein's Rocket Ship Galileo (1947) and Arthur C. Clarke's Prelude to Space (1951) as some of the early, influential modern works that focused on the scientific and engineering aspects of space travel.: 511–512 From the 1960s onward, the growing popularity of modern technology with the public also led to increasing depictions of interplanetary spaceships as based on the advanced but plausible extension of real, modern technology.[ac]: 511–512
With regards to interstellar travel, in which faster-than-light speeds are considered mostly unrealistic, more realistic depictions of the theme often focused on the idea generation ships that travel at sub-light speed for many generations before reaching their destination.[ad] Other scientifically plausible examples of interstellar travel include concepts such as suspended animation,[ae] and less often, ion, solar sail, Bussard ramjet, and time dilation.[af]: 74
Many writers introducing fictional concepts to get around the limitations of the special theory of relativity.: 75 : 511–512  Invention of completely made up devices enabling space travel has a long tradition — already in the early 20th century, Verne criticized H. G. Wells' The First Men in the Moon (1901) for abandoning realistic science (his spaceship relied on anti-gravitic material called "cavorite").: 69 : 743 While the fictitious drives "solve" many problems related to physics as understood today (namely, the difficulty of faster-than-light travel), some writers introduce new wrinkles — for example, a common trope involves the difficulty of using such drives in close proximity to other objects, in some cases allowing their use only from the outskirts of solar systems.[ag]: 75–76
While usually the method of traveling through space is just a means to an end, for some works, particularly short stories, it is a central plot device. Such works focus on themes such as the mysteries of hyperspace, or the consequences of getting lost after an error or malfunction.: 74–75 [ah]
Hyperspace is a fictional method for faster than light flight, in which a dimension or space outside of normal space-time is used. It can have many names, such as jumpspace, overspace, subspace, superspace, underspace or null space. Out of the fictitious drives, by mid-70s the concept of travelling through hyperspace has been described as having achieved the most popularity, and would subsequently be further popularized — as hyperdrive — through its use in the Star Wars franchise.: 75 
Slipstream is very similar to hyperspace. It is the method of traveling through a network of fast corridors or conduits outside of normal space-time. The concept represents a mixture of hyperspace and wormholes. Prominent examples are the Slipstream drive from Andromeda, the Borg transwarp network and the quantum slipstream drive from Voyager and the spore drive from Discovery.
In science fiction media, space folding is a method of very fast or even instantaneous travel. In the Dune franchise created by Frank Herbert, space folding is depicted as instantaneous interstellar travel effected by mutated Guild Navigators under the influence of the drug melange. Kevin R. Grazier analyzes the concepts of folding space and faster-than-light travel in the essay "Cosmic Origami" in The Science of Dune (2008).
Mrs Who took a portion of her white robe in her hands and held it tight. "You see," Mrs. Whatsit said, "if a very small insect were to move from the section of skirt in Mrs Who's right hand to that in her left, it would be quite a long walk for him if he had to walk straight across." Swiftly Mrs Who brought her hands, still holding her skirt, together. "Now, you see," Mrs Whatsit said, "he would be here, without that long trip. That is how we travel."
In the Star Trek universe folding space is depicted as an alternate form of travel compared to warp drive or slipstream. In The High Ground, terrorists on the planet Rutia IV used a space folding teleporter called an Inverter to bypass the force fields and shields of the Enterprise. In the episode Prime Factors the crew of the USS Voyager tried to buy and use a spatial trajector from the Sikarians. This wraps an object in a kind of subspace bubble, and teleports it to another location using spatial folding with a maximum range of 40,000 light-years. In the episode Vis à Vis, Voyager discovered a stranded spaceship with a coaxial warp drive. This ships engines used spatial folding instead of warp drive for locomotion.
A warp bubble is a possible hypothetical solution of the field equation of general relativity. A warp drive is a fictional superluminal spacecraft propulsion system that uses a warp bubble or a warp field for locomotion. The general concept of "warp drive" was introduced by John W. Campbell in his 1957 novel Islands of Space and was popularized by the Star Trek series.: 77
In addition to the warp bubble, wormholes are another hypothetical, mathematical solution to the field equation of general relativity. Some fictional works include concepts of space travel through wormholes or even black holes.[ai]: 511–512
Once Charles Wallace, Meg and their friend Calvin O’Keefe are transported to other planets by using tesseracts — wrinkles in the space-time continuum — the novel starts to go off in several directions at once.