Astrogation
From Wikipedia, the free encyclopedia
The word astrogation, used by science fiction writers beginning in the first half of the 20th century, denotes navigation of spacecraft, either in interplanetary travel or in interstellar travel. The mathematical principles governing interplanetary astrogation were 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 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.
