The idea of hyperdrive in most science fiction relies on the existence of a separate and adjacent dimension most commonly called "hyperspace," though various other names have been used: "Zero-space," "slipspace," "Space2," "subspace," "The Immaterium," etc. When activated, the hyperdrive shunts the starship into this other dimension, where it can cover vast distances in an amount of time greatly reduced from the time it would take in "real" space. Once it reaches the point in hyperspace that corresponds to its destination in real space, it re-emerges. Usually, hyperdrive refers to a method of travel in which it takes a measurable amount of time to go from one point to another. When the distance is covered instantaneously, the term jump drive is often used.
Explanations of why ships can travel faster than light in hyperspace vary; hyperspace may be smaller than real space or provide a shortcut between two points in real space, thus effectively increasing the ship's speed by reducing distance travelled rather than speed, or the speed of light in hyperspace is not a barrier as it is in real space. Whatever the reasoning, the general effect is that ships travelling in hyperspace seem to have broken the speed of light, appearing at their destinations much quicker and without the shift in time that the Theory of Relativity would suggest.
While in hyperspace, starships are typically isolated from the normal universe; they cannot communicate with nor perceive things in real space until they emerge. Often there can be no interaction between two ships even when both are in hyperspace. To people traveling in hyperspace, time typically moves at its normal pace, with little or no time dilation; 24 hours in hyperspace equates to 24 hours in real space. One exception is David Brin's Uplift Universe; here, hyperspace is divided into "levels" where time passes at different rates. Hyperspace itself may be portrayed as swirling colors, total blackness, or as something that would drive a human mind insane should it be viewed.
In much science fiction, hyperdrive jumps require a considerable amount of planning and calculation, with any error carrying a threat of dire consequences. Therefore, jumps may cover a much shorter distance than would actually be possible so that the navigator can stop to "look around" -- take his bearings, plot his position, and plan the next jump. The time it takes to travel in hyperspace also varies. Travel times may be in hours, days, weeks or more.
Hyperdrives allow for drama in science fiction, because ships with hyperdrive can typically only interact with other ships while in "normal space". The chance of two ships appearing in deep space to take a navigation bearing at the same time is infinitesimal. Therefore, hyperdrive ships will encounter each other most often around contested planets or space stations. Hyperdrive may also allow for dramatic escapes as the pilot "jumps" to hyperspace in the midst of battle to avoid destruction.
In some science fiction, hyperspace travel is portrayed as potentially dangerous due to the chance that the route through hyperspace may take the ship too close to a celestial body with a large gravitational field, such as a star, or a blackhole. In such scenarios, if a starship passes too close to a large gravitational field while in hyperspace, the ship is forcibly pulled out of hyperspace and reverts to normal space, or in some stories, is destroyed. Therefore, certain hyperspace "routes" may be mapped out that are safe, not passing too close to stars or other dangers. Other portrayals show less interaction between normal space and hyperspace, so that ships may actually pass through the position taken up by a celestial body in real space, without being affected.
Hyperdrives are the main FTL technology in many science fiction universes including:
- Cowboy Bebop anime series
- Animorphs series by K.A. Applegate.
- Norby series by Isaac Asimov.
- Midshipman's Hope and subsequent novels by David Feintuch.
- Starship Troopers by Robert A. Heinlein.
- Star Wars film series created by George Lucas.
- Academy series by Jack McDevitt.
- Known Space fictional universe by Larry Niven.
- Babylon 5 TV series by J. Michael Straczynski.
- Honor Harrington series by David Weber.
- Stargate: SG-1 television series by Brad Wright and Jonathan Glassner.
- Stargate: Atlantis television series by Brad Wright and Robert C. Cooper.
- Homeworld game series.
- Star Control game series.
- Halo game series.
- Warhammer 40,000 boardgame series.
- Andromeda TV series by Gene Roddenberry
- Hyperdrive TV series
Heim Theory - A controversial theory of physics that posits for a "real life hyperdrive".