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 travelling.

In science

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. Other than different characteristics and names there are lots of similarities.

Obstacles

Biosphere

Such a ship would have to be almost 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. Large, self-sustaining space habitats would be needed. For gaining experience, before sending generation ships to the stars, such a habitat could be effectively isolated from the rest of humanity for a century, or more, but remain close enough to Earth for help. This would test 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.