Editing Interstellar travel (section)

=== Slow, crewed missions ===
In crewed missions, the duration of a slow interstellar journey presents a major obstacle and existing concepts deal with this problem in different ways.<ref>{{cite web |last=Hein |first=Andreas |date=April 17, 2012 |title=How Will Humans Fly to the Stars? |url=http://www.centauri-dreams.org/?p=22561 |access-date=12 April 2013 |website=Centauri Dreams |archive-date=20 January 2013 |archive-url=https://web.archive.org/web/20130120060728/http://www.centauri-dreams.org/?p=22561 |url-status=live }}</ref> They can be distinguished by the "state" in which humans are transported on-board of the spacecraft.

==== Generation ships ====
{{Main|Generation ship}}
A [[generation ship]] (or '''world ship''') is a type of [[interstellar ark]] in which the crew that arrives at the destination is descended from those who started the journey. Generation ships are not currently feasible because of the difficulty of constructing a ship of the enormous required scale and the great biological and sociological problems that life aboard such a ship raises.<!---So? nothing else in this article is, either---><ref>{{cite journal|last=Hein|first=A. M.|display-authors=etal|title=World Ships: Architectures & Feasibility Revisited|journal=Journal of the British Interplanetary Society|date=2012|volume=65|pages=119–133|url=https://www.academia.edu/2111006|bibcode=2012JBIS...65..119H|access-date=1 November 2017|archive-date=16 December 2021|archive-url=https://web.archive.org/web/20211216042335/https://www.academia.edu/2111006|url-status=live}}</ref><ref name="Hein 2020 75–104">{{cite journal|last=Hein|first=A.M.|author2=Smith, C.|author3=Marin, F.|author4=Staats, K.|title=World Ships: Feasibility and Rationale|journal=Acta Futura|date=2020|volume=12|pages=75–104|doi=10.5281/zenodo.3747333|arxiv=2005.04100|s2cid=218571111|url=https://zenodo.org/record/3747333|access-date=1 June 2020|archive-date=16 May 2021|archive-url=https://web.archive.org/web/20210516224552/https://zenodo.org/record/3747333|url-status=live}}</ref><ref>{{cite journal|last=Bond|first=A.|author2=Martin, A.R.|title=World Ships – An Assessment of the Engineering Feasibility|journal=Journal of the British Interplanetary Society|date=1984|volume=37|pages=254–266|bibcode = 1984JBIS...37..254B }}</ref><ref>{{cite book|last=Frisbee|first=R.H.|title=Limits of Interstellar Flight Technology in Frontiers of Propulsion Science|date=2009|publisher=Progress in Astronautics and Aeronautics}}</ref><ref>{{cite web |last=Hein |first=Andreas M. |title=Project Hyperion: The Hollow Asteroid Starship – Dissemination of an Idea |url=http://www.icarusinterstellar.org/project-hyperion-the-hollow-asteroid-starship-dissemination-of-an-idea/ |url-status=dead |archive-url=https://web.archive.org/web/20130410004948/http://www.icarusinterstellar.org/project-hyperion-the-hollow-asteroid-starship-dissemination-of-an-idea/ |archive-date=10 April 2013 |access-date=12 April 2013 |website=Icarus Interstellar}}</ref>

==== Suspended animation ====
{{Main|Sleeper ship}}

Scientists and writers have postulated various techniques for [[suspended animation]]. These include human [[hibernation]] and [[cryonics|cryonic preservation]]. Although neither is currently practical, they offer the possibility of [[sleeper ship]]s in which the passengers lie inert for the long duration of the voyage.<ref>{{cite journal|title=Various articles on hibernation|journal=Journal of the British Interplanetary Society|date=2006|volume=59|pages=81–144}}</ref>

==== Frozen embryos ====
{{Main|Embryo space colonization}}
A [[robotic]] interstellar mission carrying some number of frozen early stage human [[embryo]]s is another theoretical possibility. This method of [[space colonization]] requires, among other things, the development of an [[artificial uterus]], the prior detection of a habitable [[terrestrial planet]], and advances in the field of fully autonomous [[robotics|mobile robots]] and educational robots that would replace human parents.<ref>{{cite journal|last=Crowl|first=A.|author2=Hunt, J.|author3=Hein, A.M.|title=Embryo Space Colonisation to Overcome the Interstellar Time Distance Bottleneck|journal=Journal of the British Interplanetary Society|date=2012|volume=65|pages=283–285|url=http://www.jbis.org.uk/paper.php?p=2012.65.283|bibcode=2012JBIS...65..283C|access-date=12 April 2013|archive-date=31 July 2020|archive-url=https://web.archive.org/web/20200731004527/http://www.jbis.org.uk/paper.php?p=2012.65.283|url-status=live}}</ref>

==== Island hopping through interstellar space ====
Interstellar space is not completely empty; it contains trillions of icy bodies ranging from small asteroids ([[Oort cloud]]) to possible [[rogue planet]]s. There may be ways to take advantage of these resources for a good part of an interstellar trip, slowly hopping from body to body or setting up waystations along the way.<ref>{{cite web |last=Gilster |first=Paul |date=12 February 2012 |title='Island-Hopping' to the Stars |url=http://www.centauri-dreams.org/?p=21719 |access-date=12 June 2015 |work=Centauri Dreams |archive-date=18 November 2021 |archive-url=https://web.archive.org/web/20211118074304/https://www.centauri-dreams.org/2012/02/13/island-hopping-to-the-stars/ |url-status=live }}</ref>