Astrogation
Astrogation is the planning of a route through space and the actual navigation of spacecraft, either in interplanetary travel or in interstellar travel. The mathematical principles governing interplanetary astrogation were first derived by mathematical physicists in the 19th and 20th centuries.
Two tasks define navigation: (1) determining present location, and (2) planning a safe and reliable means of reaching a destination. An example of an interstellar approach to describing the location of Earth is the plaque carried by the Pioneer 10 and Pioneer 11 spacecraft, where pulsars are used as references.
Route planning is greatly affected by means of propulsion, gravitational potential, obstacles and other hazards (such as radiation), and distance or time. Since no known extrasolar star is closer than four light years away, science fiction writers commonly introduce speculative or fictional work-arounds to the awkward time/distance problem. However, some novels such as Encounter With Tiber, co-authored by astronaut Buzz Aldrin (one of the few people to have set foot on the Moon), treat distance and time more realistically as part of the plot.
The Faster Than Light (FTL) work-arounds tend to fall into several main categories with a couple of somewhat unique sub-categories. FTL ideas such as Hyperspace of Star Wars and slip space of the Andromeda Ascendant TV show or the warp drive of Star Trek and wormhole drive of the Stargate: Atlantis TV show. With the unique methods of getting a spaceship to FTL external to the ship such as the Babylon 5 Jump Gates (one gate into a 'Hyperspace' dimension and one gate out) or the Mass Effect Mass Effect Relays (one relay 'throws' the spaceship into FTL and another relay catches the ship in FTL and returns it to sub-light speeds). The Andromeda Ascendant Slip Space FTL method cannot be navigated by a computer or the ship's AI and needs and 'organic' pilot. The astrogation computer is for determining location in real space.
Some stories FTL methods are still slow in 'real time', we are dealing with distances measured in Light YEARS after all, and some FTL methods have Time Shear where there is less apparent time for the ships crew where years might go by for the galaxy. Such story plot lines usually involve some form of Cryogenic Sleep or Suspended Animation for the crew. A good example of this is seen in the HALO games. Though the HALO games Slip Space behaves much more like Hyperspace and apparently is one the slowest 'common' FTL drives out there needing cryo-sleep. Cryogenic Sleep and Suspended Animation or Generational Ships are usually plot elements of 'Slow Boat' sub-light trips such as in colony ships. These ships usually have a astrogation type computer to automatically keep the ship on course past any programed course changes or minor unexpected happenings with instructions to wake the Command Staff for major unexpected happenings.
The term astrogation was first used by science fiction writers beginning in the first half of the 20th century.