Generation ship

A generation ship, or generation starship, is a hypothetical type of interstellar ark starship that travels at sub-light speed.

Since such a ship might take centuries to thousands of years to reach even nearby stars, the original occupants of a generation ship would grow old and die, leaving their descendants to continue traveling.

The concept of a generation starship is a good example of how science and fiction influence each other. Many space scientists and engineers who contributed to the concept of a generation starship were also science fiction writers.

Robert H. Goddard, the rocket pioneer, was the first to write about very long duration interstellar journeys in his "The Last Migration" (1918). In this he described the death of the Sun and the necessity of an "interstellar ark". The crew would face the centuries of travel by sleeping and would be awakened when they reach another star system.

Konstantin E. Tsiolkovsky father of astronautic theory first described the need for multiple generations of passengers in his essay, "The Future of Earth and Mankind" (1928), a space colony equipped with engines that travels thousands of years which he called "Noah's Ark".

John D. Bernals's essay was the first publication to reach the public and influence other writers. He wrote about the concept of human evolution and mankind's future in space through methods of living that we now describe as a generation starship, and which could be seen in the generic word "globes".

The Enzmann starship is categorised slow boat because of the Astronomy Magazine title “Slow Boat to Centauri” (1977). Gregory Matloffs concept is called colony ship and Alan Bond called his concept world ship.

Such a ship would have to be entirely self-sustaining providing energy, food, air, and water for everyone on board. It must also have extraordinarily reliable systems that could be maintained by the ship's inhabitants over long periods of time. This would require testing whether thousands of humans can survive on their own before sending them beyond the reach of help. There are also the concerns of immune systems atrophying in the ship's environment. Small artificial closed ecosystems, including Biosphere 2, have been built in an attempt to work out the engineering difficulties in such a system with mixed results.

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