Editing Interstellar travel (section)

== Designs and studies ==

=== Project Hyperion ===
{{Main|Project Hyperion (interstellar)}}
[[Project Hyperion (interstellar)|Project Hyperion]] has looked into various feasibility issues of crewed interstellar travel.<ref>{{cite web|title=Icarus Interstellar – Project Hyperion|url=http://www.icarusinterstellar.org/projects/project-hyperion/|access-date=13 April 2013|archive-date=20 April 2013|archive-url=https://web.archive.org/web/20130420063618/http://www.icarusinterstellar.org/projects/project-hyperion/|url-status=live}}</ref><ref>{{cite report|url=https://www.academia.edu/2111006|title=World Ships – Architectures & Feasibility Revisited|author=Hein, Andreas|date=January 2012|access-date=7 February 2013|display-authors=etal|archive-date=16 December 2021|archive-url=https://web.archive.org/web/20211216042335/https://www.academia.edu/2111006|url-status=live}}</ref><ref>{{cite journal | last1 = Smith | first1 = Cameron M | year = 2014 | title = Estimation of a genetically viable population for multigenerational interstellar voyaging: Review and data for project Hyperion | journal = Acta Astronautica | volume = 97 | pages = 16–29 | doi = 10.1016/j.actaastro.2013.12.013 | bibcode = 2014AcAau..97...16S }}</ref>  Notable results of the project include an assessment of world ship system architectures and adequate population size.<ref>{{cite journal |last1=Hein |first1=Andreas M. |last2=Pak |first2=Mikhail |last3=Pütz |first3=Daniel |last4=Bühler |first4=Christian |last5=Reiss |first5=Philipp |title=World ships—architectures & feasibility revisited |journal=Journal of the British Interplanetary Society |date=2012 |volume=65 |issue=4 |page=119|url=https://www.researchgate.net/publication/236177990}}</ref><ref>{{cite journal |last1=Smith |first1=Cameron M. |title=Estimation of a genetically viable population for multigenerational interstellar voyaging: Review and data for project Hyperion |journal=Acta Astronautica |date=2014 |volume=97 |pages=16–29 |doi=10.1016/j.actaastro.2013.12.013 |bibcode=2014AcAau..97...16S |url=https://www.sciencedirect.com/science/article/pii/S0094576513004669}}</ref><ref>{{cite web |last1=Fecht |first1=Sarah |title=How Many People Does It Take to Colonize Another Star System? |url=https://www.popularmechanics.com/space/deep-space/a10369/how-many-people-does-it-take-to-colonize-another-star-system-16654747/ |website=Popular Mechanics |date=2 April 2014 |access-date=24 February 2021}}</ref><ref>{{cite web |last1=Wall |first1=Mike |title=Want to Colonize an Alien Planet? Send 40,000 People |url=https://www.space.com/26603-interstellar-starship-colony-population-size.html |website=Space.com |date=28 July 2014 |access-date=24 February 2021}}</ref> Its members continue to publish on crewed interstellar travel in collaboration with the [[Initiative for Interstellar Studies]].<ref name="Hein 2020 75–104"/>

=== Enzmann starship ===
{{Main|Enzmann starship}}
The Enzmann starship, as detailed by [[G. Harry Stine]] in the October 1973 issue of ''[[Analog Science Fiction and Fact|Analog]]'', was a design for a future [[Starship (interstellar spacecraft)|starship]], based on the ideas of Robert Duncan-Enzmann. The spacecraft itself as proposed used a 12,000,000 ton ball of frozen [[deuterium]] to power 12–24 thermonuclear pulse propulsion units. Twice as long as the [[Empire State Building]] is tall and assembled in-orbit, the spacecraft was part of a larger project preceded by [[interstellar probe]]s and telescopic observation of target star systems.<ref>{{cite web |url=http://www.centauri-dreams.org/?p=1142 |work=Centauri Dreams |title=A Note on the Enzmann Starship |first=Paul |last=Gilster |date=April 1, 2007 |access-date=18 November 2010 |archive-date=30 June 2011 |archive-url=https://web.archive.org/web/20110630042240/http://www.centauri-dreams.org/?p=1142 |url-status=live }}</ref>

=== NASA research ===
[[National Aeronautics and Space Administration|NASA]] has been researching interstellar travel since its formation, translating important foreign language papers and conducting early studies on applying fusion propulsion, in the 1960s, and laser propulsion, in the 1970s, to interstellar travel.

In 1994, NASA and JPL cosponsored a "Workshop on Advanced Quantum/Relativity Theory Propulsion" to "establish and use new frames of reference for thinking about the faster-than-light (FTL) question".<ref>{{cite journal |last1=Bennett |first1=Gary |last2=Forward |first2=Robert |last3=Frisbee |first3=Robert |title=Report on the NASA/JPL Workshop on advanced quantum/relativity theory propulsion |url=https://arc.aiaa.org/doi/pdf/10.2514/6.1995-2599 |journal=31st Joint Propulsion Conference and Exhibit |publisher=American Institute of Aeronautics and Astronautics |access-date=8 September 2020 |doi=10.2514/6.1995-2599 |date=10 July 1995}}</ref>

The [[National Aeronautics and Space Administration|NASA]] [[Breakthrough Propulsion Physics Program]] (terminated in FY 2003 after a 6-year, $1.2-million study, because "No breakthroughs appear imminent.")<ref>[https://web.archive.org/web/19991002003540/http://www.grc.nasa.gov/WWW/bpp "Breakthrough Propulsion Physics"] project at NASA Glenn Research Center, Nov 19, 2008</ref> identified some breakthroughs that are needed for interstellar travel to be possible.<ref>{{Cite web |url=http://www.nasa.gov/centers/glenn/technology/warp/warp.html |title=Warp Drive, When? |work=NASA Breakthrough Technologies |date=January 26, 2009 |access-date=2 April 2010 |archive-date=7 July 2008 |archive-url=https://web.archive.org/web/20080707043144/http://www.nasa.gov/centers/glenn/technology/warp/warp.html |url-status=live }}</ref>

[[Geoffrey A. Landis]] of NASA's [[Glenn Research Center]] states that a laser-powered interstellar sail ship could possibly be launched within 50 years, using new methods of space travel. "I&nbsp;think that ultimately we're going to do it, it's just a question of when and who," Landis said in an interview. Rockets are too slow to send humans on interstellar missions. Instead, he envisions interstellar craft with extensive sails, propelled by laser light to about one-tenth the speed of light. It would take such a ship about 43 years to reach Alpha Centauri if it passed through the system without stopping. Slowing down to stop at Alpha Centauri could increase the trip to 100 years,<ref>{{cite web|url=http://www.space.com/scienceastronomy/generalscience/star_voyage_020319-1.html |title=Sailing to the Stars: Sex and Society Aboard the First Starships |website=[[Space.com]] |access-date=2009-04-03 |url-status=dead |archive-url=https://web.archive.org/web/20090327233721/http://www.space.com/scienceastronomy/generalscience/star_voyage_020319-1.html |archive-date=2009-03-27 }} Malik, Tariq, "Sex and Society Aboard the First Starships." Science Tuesday, Space.com March 19, 2002.</ref> whereas a journey without slowing down raises the issue of making sufficiently accurate and useful observations and measurements during a fly-by.

=== 100 Year Starship study ===
The [[100 Year Starship]] (100YSS) study was the name of a one-year project to assess the attributes of and lay the groundwork for an organization that can carry forward the 100 Year Starship vision. 100YSS-related symposia were organized between 2011 and 2015.

[[Harold Sonny White (NASA Scientist)|Harold ("Sonny") White]]<ref>{{cite web|url=http://www.icarusinterstellar.org/team/harold-white/|title=Dr. Harold "Sonny" White – Icarus Interstellar|work=icarusinterstellar.org|access-date=12 June 2015|url-status=dead|archive-url=https://web.archive.org/web/20150601090330/http://www.icarusinterstellar.org/team/harold-white/|archive-date=1 June 2015}}</ref> from NASA's Johnson Space Center is a member of Icarus Interstellar,<ref>{{cite web|url=http://www.icarusinterstellar.org|title=Icarus Interstellar – A nonprofit foundation dedicated to achieving interstellar flight by 2100.|work=icarusinterstellar.org|access-date=12 June 2015|archive-date=2 December 2013|archive-url=https://web.archive.org/web/20131202234741/http://www.icarusinterstellar.org/|url-status=dead}}</ref> the nonprofit foundation whose mission is to realize interstellar flight before the year 2100. At the 2012 meeting of 100YSS, he reported using a [[White–Juday warp-field interferometer|laser to try to warp spacetime]] by 1 part in 10 million with the aim of helping to make interstellar travel possible.<ref>{{cite web | url= http://www.space.com/17628-warp-drive-possible-interstellar-spaceflight.html | title= Warp Drive May Be More Feasible Than Thought, Scientists Say | author= Moskowitz, Clara | date= 17 September 2012 | website= space.com | access-date= 29 December 2012 | archive-date= 17 August 2013 | archive-url= https://web.archive.org/web/20130817082143/http://www.space.com/17628-warp-drive-possible-interstellar-spaceflight.html | url-status= live }}</ref>

=== Other designs ===
* [[Project Orion (nuclear propulsion)|Project Orion]], human crewed interstellar ship (1958–1968).
* [[Project Daedalus]], uncrewed interstellar probe (1973–1978).
* Starwisp, uncrewed interstellar probe (1985).<ref>{{cite journal |title= Starwisp – An ultra-light interstellar probe |last= Forward |first= R. L. |journal= Journal of Spacecraft and Rockets |volume= 22 |number= 3 |date= May–June 1985 |pages= 345–350 |doi= 10.2514/3.25754 |bibcode= 1985JSpRo..22..345F}}</ref>
* [[Project Longshot]], uncrewed interstellar probe (1987–1988).
* [[Starseed launcher|Starseed/launcher]], fleet of uncrewed interstellar probes (1996).
* [[Project Valkyrie]], human crewed interstellar ship (2009).
* [[Project Icarus (interstellar)|Project Icarus]], uncrewed interstellar probe (2009–2014).
* Sun-diver, uncrewed interstellar probe.<ref>{{cite journal | url= http://www.ugcs.caltech.edu/~diedrich/solarsails/docs/Near-term_beam_sail.pdf | author= Benford, James |author2=Benford, Gregory | title= Near-Term Beamed Sail Propulsion Missions: Cosmos-1 and Sun-Diver | journal= Beamed Energy Propulsion | year= 2003 | volume= 664 | page= 358 | publisher= Department of Physics, University of California, Irvine | doi= 10.1063/1.1582124 | bibcode= 2003AIPC..664..358B | archive-url= https://web.archive.org/web/20141024185623/http://www.ugcs.caltech.edu/~diedrich/solarsails/docs/Near-term_beam_sail.pdf | archive-date= 2014-10-24 | url-status= dead}}</ref>
* [[Project Dragonfly (space study)|Project Dragonfly]], small laser-propelled interstellar probe (2013–2015).
* [[Breakthrough Starshot]], fleet of uncrewed interstellar probes, announced on 12 April 2016.<ref>{{cite web |url=http://breakthroughinitiatives.org/Initiative/3 |title=Breakthrough Starshot |work=Breakthrough Initiatives |date=12 April 2016 |access-date=2016-04-12 |archive-date=12 April 2016 |archive-url=https://web.archive.org/web/20160412180305/http://www.breakthroughinitiatives.org/Initiative/3 |url-status=live }}</ref><ref>[http://breakthroughinitiatives.org/Concept/3 Starshot – Concept] {{Webarchive|url=https://web.archive.org/web/20160903181459/http://breakthroughinitiatives.org/Concept/3 |date=3 September 2016 }}.</ref><ref>{{cite web|url=http://breakthroughinitiatives.org/Target/3|title=Breakthrough Initiatives|website=breakthroughinitiatives.org|access-date=14 April 2016|archive-date=28 April 2017|archive-url=https://web.archive.org/web/20170428235912/http://breakthroughinitiatives.org/Target/3|url-status=live}}</ref>
* [[Solar One (interstellar)|Solar One]], crewed spacecraft that would combine beamed-powered propulsion, electromagnetic propulsion, and nuclear propulsion (2020).<ref>{{Cite web|date=2020-05-22|title=Solar One – a concept for interstellar travel|url=https://www.innovationnewsnetwork.com/solar-one-a-concept-for-interstellar-travel/5239/|access-date=2020-12-07|website=Innovation News Network|language=en-GB|archive-date=7 January 2023|archive-url=https://web.archive.org/web/20230107214530/https://www.innovationnewsnetwork.com/solar-one-a-concept-for-interstellar-travel/5239/|url-status=live}}</ref>