Editing Interstellar ark (section)

== Thrust concepts ==
Another concern is selection of power sources and mechanisms which would remain viable for the long time spans involved in [[interstellar travel]] through the desert of space. The longest-lived [[Space probe|space probes]] are the [[Voyager program]] probes, which use [[radioisotope thermoelectric generator]]s having a useful lifespan of a mere 50 years.

One propulsion method for a crewed spacecraft could be a fusion microexplosion [[nuclear pulse propulsion]] system (like that proposed in [[Project Daedalus]]) that may allow it to obtain an interstellar cruising velocity of up to 10% of the [[speed of light]]. However, if the ship is capable of transits requiring hundreds of thousands of years, chemical and [[Gravity assist|gravitational slingshot]] propulsion may be sufficient.<ref>R.W. Moir and W.L. Barr (2005) [http://ralphmoir.com/media/jBIS.pdf "Analysis of Interstellar Spacecraft Cycling between the Sun and the Near Stars"] {{Webarchive|url=https://web.archive.org/web/20131102212601/http://ralphmoir.com/media/jBIS.pdf |date=2 November 2013 }} ''Journal of the British Interplanetary Society'' '''58,''' pp. 332–341</ref><ref>Frederik Ceyssens, Maarten Driesen, Kristof Wouters, Pieter-Jan Ceyssens, Lianggong Wen (2011) [https://arxiv.org/ftp/arxiv/papers/1109/1109.5318.pdf "Organizing and financing interstellar space projects – A bottom-up approach"] {{Webarchive|url=https://web.archive.org/web/20200407112337/https://arxiv.org/ftp/arxiv/papers/1109/1109.5318.pdf |date=7 April 2020 }} (DARPA/NASA, Orlando, Florida: [http://100yss.org/ 100 Year Starship conference] {{Webarchive|url=https://web.archive.org/web/20120914082843/http://100yss.org/ |date=14 September 2012 }})</ref>