Editing SpaceShipTwo (section)

== Design overview ==
The SpaceShipTwo project was based in part on technology developed for the first-generation [[SpaceShipOne]], which was part of the [[Scaled Composites Tier One]] program, funded by [[Paul Allen]]. The Spaceship Company licensed this technology from [[Mojave Aerospace Ventures]], a joint venture of Paul Allen and [[Burt Rutan]], the designer of the predecessor technology.

SpaceShipTwo was a [[Aspect ratio (aerodynamics)|low-aspect-ratio]] passenger [[spaceplane]]. Its capacity was planned to be eight people — six passengers and two pilots. The SpaceShipTwo spaceplanes never flew with more than 6 people onboard (4 passengers, 2 pilots). The [[Apsis|apogee]] of the new craft was designed to be approximately {{cvt|110|km}} in the lower [[thermosphere]], {{cvt|10|km}} higher than the [[Kármán line]] but as of July 2021, the maximum height reached was 89.9&nbsp;km.<ref>{{cite web |url=https://www.bbc.co.uk/news/science-environment-47336617 |title=Virgin's Unity plane rockets skyward |date=22 February 2019 |publisher=BBC}}</ref> In the end, the SpaceShipTwos never broke the 100&nbsp;km limit. The predecessor craft SpaceShipOne's target was also 100&nbsp;km but the last flight reached an altitude of {{cvt|112|km}}.<ref name=ft>{{Cite web |url=http://www.scaled.com/projects/tierone/combined_white_knight_spaceshipone_flight_tests |title=SpaceShipOne Flight Tests |work=Scaled Composites |url-status=dead |archive-url=https://web.archive.org/web/20100822194232/http://www.scaled.com/projects/tierone/combined_white_knight_spaceshipone_flight_tests |archive-date=2010-08-22 }}</ref> SpaceShipTwo was designed to reach {{cvt|4200|km/h}}, using a single [[hybrid rocket]] engine — the [[RocketMotorTwo]].<ref name="RocketMotorTwo HotFire Tests">{{cite web |url=http://www.scaled.com/projects/rocket_motor_2_hot-fire_test_summaries|title=Project Test Summaries|access-date=5 April 2012|publisher=Scaled Composite|archive-url=https://web.archive.org/web/20140222202346/http://www.scaled.com/projects/rocket_motor_2_hot-fire_test_summaries|archive-date=22 February 2014|url-status=dead}}</ref> It launched from its mothership, [[Scaled Composites White Knight Two|White Knight Two]], at an altitude of {{cvt|13500|m}},<ref>{{Cite web|url=https://www.youtube.com/watch?v=yhY9bJfi4xY|title=Replay! Virgin Galactic's 2nd commercial crew spaceflight with VSS Unity - Full Broadcast|date=10 August 2023 |via=www.youtube.com}}</ref> and reached [[supersonic speed]] within 8 seconds. After 70 seconds, the rocket engine cut out and the spacecraft coasted to its peak altitude. SpaceShipTwo's crew cabin was {{cvt|3.7|m}} long and {{cvt|2.3|m}} in diameter.<ref name="flightglobal-unveil">{{cite web |url=http://www.flightglobal.com/articles/2008/01/23/221031/pictures-virgin-galactic-unveils-dyna-soar-style-spaceshiptwo-design-and-twin-fuselage-white-knight.html|title=Pictures: Virgin Galactic unveils Dyna-Soar style SpaceShipTwo design and twin-fuselage White Knight II configuration|access-date=23 January 2008|author=Rob Coppinger|publisher=Flightglobal}}</ref> The wing span was {{cvt|8.2|m}}, the length was {{cvt|18|m}} and the tail height was {{cvt|4.6|m}}.<ref name="VirginGalactic-Presspack">{{cite web|url=http://www.virgingalactic.com/pressftp/index_full.php|title=Spaceship Unveil Presspack|access-date=10 February 2008|publisher=Virgin Galactic|url-status=dead|archive-url=https://web.archive.org/web/20080216043101/http://www.virgingalactic.com/pressftp/index_full.php|archive-date=16 February 2008}}</ref>

SpaceShipTwo used a [[Atmospheric entry#Feathered entry|feathered reentry system]], feasible due to the low speed of reentry. In contrast, orbital spacecraft re-enter at orbital speeds, close to {{cvt|25000|km/h}}, using heat shields. SpaceShipTwo was furthermore designed to re-enter the atmosphere at any angle.<ref name="zdnet-btl-blog">{{cite web|url=http://blogs.zdnet.com/BTL/?p=7678|title=Virgin Galactic unveils SpaceShipTwo; Plans open architecture spaceship|date=23 January 2008|access-date=10 February 2008|author=Dignan, Larry|publisher=ZDnet.com|archive-date=6 December 2013|archive-url=https://web.archive.org/web/20131206023230/http://www.zdnet.com/blog/btl/virgin-galactic-unveils-spaceshiptwo-plans-open-architecture-spaceship/7678|url-status=dead}}</ref> It decelerated through the atmosphere, switching to a gliding position at an altitude of {{cvt|24|km}}, and took 25 minutes to glide back to the [[spaceport]].

SpaceShipTwo and White Knight Two were, respectively, roughly twice the size of the first-generation SpaceShipOne and mothership [[Scaled Composites White Knight|White Knight]], which won the [[Ansari X Prize]] in 2004. SpaceShipTwo had {{cvt|43|and|33|cm}}-diameter windows for the passengers' viewing pleasure,<ref name="VirginGalactic-Presspack"/> and all seats reclined back during landing to decrease the discomfort of G-forces.<ref name="space2">{{cite web|url=http://www.space.com/news/060828_spaceshiptwo_next.html|title=Virgin Galactic Unveils SpaceShipTwo Interior Concept|access-date=6 April 2007|date=28 September 2006|author=Tariq Malik|publisher=SpaceNews}}</ref> In 2008, [[Burt Rutan]] remarked on the safety of the vehicle:
{{blockquote|This vehicle is designed to go into the atmosphere in the worst case straight in or upside down and it'll correct. This is designed to be at least as safe as the early airliners in the 1920s ... Don't believe anyone that tells you that the safety will be the same as a modern airliner, which has been around for 70 years.<ref name="zdnet-btl-blog"/>}}

In September 2011, the safety of SpaceShipTwo's feathered reentry system was tested when the crew briefly lost control of the craft during a gliding test flight. Control was reestablished after the spaceplane entered its feathered configuration, and it landed safely after a 7-minute flight.<ref name=SpaceCoOct>[http://www.space.com/13297-virgin-galactic-spaceshiptwo-test-flight-glitch.html "Virgin Galactic's private spaceship makes safe landing after tense test flight"] SPACE.com 17 October 2011 Retrieved 18 October 2011</ref>