Interstellar space travel is manned or unmanned travel between stars. The concept of interstellar travel in starships is a staple of science fiction. Interstellar travel is conceptually much more difficult than interplanetary travel. Intergalactic travel, or travel between different galaxies, would be even more difficult.
Many scientific papers have been published about related concepts. Given sufficient travel time and engineering work, both unmanned and sleeper ship interstellar travel seem possible, though both present considerable technological and economic challenges that are unlikely to be met in the near future, particularly for manned probes. NASA, ESA and other space agencies have been engaging in research into these topics for several years, and have accumulated a number of theoretical approaches.
Energy requirements appear to make interstellar travel impractical for generation ships, but less so for heavily shielded sleeper ships.
Famous quotes containing the word travel:
“I have found out that there aint no surer way to find out whether you like people or hate them than to travel with them.”
—Mark Twain [Samuel Langhorne Clemens] (18351910)