The Scaled Composites Model 348 White Knight Two (WK2) is a quadjet

cargo aircraft A cargo aircraft (also known as freight aircraft, freighter, airlifter or cargo jet) is a fixed-wing aircraft that is designed or converted for the carriage of cargo rather than passengers. Such aircraft generally feature one or more large door ...

that was used to lift the

SpaceShipTwo The Scaled Composites Model 339 SpaceShipTwo (SS2) was an air-launched suborbital spaceplane type designed for space tourism. It was manufactured by The Spaceship Company, a California-based company owned by Virgin Galactic. SpaceShipTwo was ...

(SS2)

spacecraft A spacecraft is a vehicle that is designed spaceflight, to fly and operate in outer space. Spacecraft are used for a variety of purposes, including Telecommunications, communications, Earth observation satellite, Earth observation, Weather s ...

to release altitude. It was developed by

Scaled Composites Scaled Composites (often called simply Scaled) is an American aerospace company founded by Burt Rutan and currently owned by Northrop Grumman. It is located at the Mojave Air and Space Port in Mojave, California, United States. Founded to d ...

from 2007 to 2010 as the first stage of

Tier 1b Tier or tiers may refer to: Groupings *Organizational, a ranking relationship involving order in a collective and its subordinate components *Ranking, a relationship involving order between a set of observations or variables *Data center tiers, ...

, a two-stage to suborbital-space crewed launch system. WK2 is based on the successful mothership to

SpaceShipOne SpaceShipOne is an experimental air launch, air-launched rocket-powered aircraft with sub-orbital spaceflight capability at speeds of up to / using a hybrid rocket motor. The design features a unique "Feathering (reentry), feathering" atmosph ...

White Knight A white knight is a mythological figure and literary stock character. They are portrayed alongside a black knight as diametric opposites. A white knight usually represents a heroic warrior fighting against evil, with the role in medieval literatu ...

, which itself was based on

Proteus In Greek mythology, Proteus ( ; ) is an early prophetic sea god or god of rivers and oceanic bodies of water, one of several deities whom Homer calls the "Old Man of the Sea" (''hálios gérôn''). Some who ascribe a specific domain to Prote ...

. With an "

open architecture Open architecture is a type of computer architecture or software architecture intended to make adding, upgrading, and swapping components with other computers easy. For example, the IBM PC, Amiga 2000 and Apple IIe have an open architecture supp ...

" design and explicit plans for multi-purpose use, the aircraft could also operate as a zero-g aircraft for passenger training or

microgravity Weightlessness is the complete or near-complete absence of the sensation of weight, i.e., zero apparent weight. It is also termed zero g-force, or zero-g (named after the g-force) or, incorrectly, zero gravity. Weight is a measurement of the fo ...

science flights, handle missions in high-altitude testing more generally, or be used to launch payloads other than SpaceShipTwo. A study of use of the aircraft as a

forest fire A wildfire, forest fire, or a bushfire is an unplanned and uncontrolled fire in an area of combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identified as a bushfire ( in Australia), dese ...

water bomber has also been mentioned, one that would utilize a large carbon composite water tank that could be quickly replenished to make repeat runs over fires. The first White Knight Two is named VMS ''Eve'' after

Richard Branson Sir Richard Charles Nicholas Branson (born 18 July 1950) is an English business magnate who co-founded the Virgin Group in 1970, and controlled 5 companies remaining of once more than 400. Branson expressed his desire to become an entrepreneu ...

's mother Eve Branson; it was officially unveiled on July 28, 2008, and flew for the first time on December 21, 2008. The second was expected to be named VMS ''Spirit of Steve Fossett'' after Branson's close friend

Steve Fossett James Stephen Fossett (April 22, 1944 – September 3, 2007) was an American businessman and a record-setting aviator, sailor, and adventurer. He was the first person to fly solo nonstop around the world in a balloon and in a fixed-wing aircraf ...

, who died in an aircraft accident in 2007. , it is not clear if any other SS2 and WK2 vehicles than VSS ''Enterprise'', VSS ''Unity'' and VMS ''Eve'' will actually be built (especially, as of 2024, VMS ''Spirit of Steve Fossett'' has not been built).

History

In 2008, Virgin Galactic ordered two White Knight Two vehicles. Together, WK2 and SS2 were to form the basis for

Virgin Galactic Virgin Galactic Holdings, Inc. is a British-American spaceflight company founded by Richard Branson and the Virgin Group conglomerate, which retains an 11.9% stake through Virgin Investments Limited. It is headquartered in California, and opera ...

's fleet of suborbital spaceplanes. In November 2010, The Spaceship Company had announced that it planned to build at least three additional White Knight Two aircraft and an additional five

rocket planes, the aircraft to be built by Virgin after the initial prototypes of each craft are built by

.Spacecraft factory to break ground in Mojave
''

Los Angeles Times The ''Los Angeles Times'' is an American Newspaper#Daily, daily newspaper that began publishing in Los Angeles, California, in 1881. Based in the Greater Los Angeles city of El Segundo, California, El Segundo since 2018, it is the List of new ...

'', 2010-11-08, accessed 2010-11-09. During 2012–2014, Virgin Galactic was also considering use of the WhiteKnightTwo as the air-launch platform for a new two-stage liquid-fueled rocket small satellite launcher called

LauncherOne LauncherOne was a two-stage orbital launch vehicle developed and flown by Virgin Orbit that had operational flights from 2021 to 2023, after being in development from 2007 to 2020. It was an air-launched rocket, designed to carry smallsat ...

. In the event—by late 2015—they decided to use a larger carrier aircraft for the job.

Design

White Knight Two is roughly three times larger than

in order to perform a captive flight with the larger

spacecraft. The WK2 is similar in

wingspan The wingspan (or just span) of a bird or an airplane is the distance from one wingtip to the opposite wingtip. For example, the Boeing 777–200 has a wingspan of , and a wandering albatross (''Diomedea exulans'') caught in 1965 had a wingsp ...

to a

Boeing B-29 Superfortress The Boeing B-29 Superfortress is a retired American four-engined propeller-driven heavy bomber, designed by Boeing and flown primarily by the United States during World War II and the Korean War. Named in allusion to its predecessor, the Bo ...

. White Knight Two is a very modern aircraft, as even the flight control cables are constructed of carbon fiber, using a new patented design. WK2 was planned to provide preview flights offering several seconds of

weightlessness Weightlessness is the complete or near-complete absence of the sensation of weight, i.e., zero apparent weight. It is also termed zero g-force, or zero-g (named after the g-force) or, incorrectly, zero gravity. Weight is a measurement of the fo ...

before the suborbital event. It was intended to have a service ceiling of about 60,000 ft (18 km), offering a dark blue sky to passengers. This would have allowed tourists to practice before the real flight. White Knight Two is of twin fuselage design with four

jet engine A jet engine is a type of reaction engine, discharging a fast-moving jet (fluid), jet of heated gas (usually air) that generates thrust by jet propulsion. While this broad definition may include Rocket engine, rocket, Pump-jet, water jet, and ...

s mounted two on each wing. One fuselage was planned to be an exact replica of that of SpaceShipTwo (to allow tourist training), and the other was planned to offer 'cut-rate' trips to the stratosphere. The design is quite different from the White Knight, both in size, use of tail, engine configuration and placement of cockpit(s). The White Knight used two

T-tail A T-tail is an empennage wikt:configuration, configuration in which the tailplane of an aircraft is mounted to the top of the vertical stabilizer, fin. The arrangement looks like the capital letter T, hence the name. The T-tail differs fr ...

s, but the White Knight Two uses two

cruciform tail The cruciform tail is an aircraft empennage configuration which, when viewed from the aircraft's front or rear, looks much like a cross. The usual arrangement is to have the tailplane, horizontal stabilizer intersect the vertical tail somewhere ...

s. Engine configuration is also very different. White Knight Two has four engines hung underneath the wings on pylons while White Knight's pair of engines were on either side of its single fuselage.

Timeline of introduction

Virgin Galactic contracted aerospace designer

Burt Rutan Elbert Leander "Burt" Rutan (; born June 17, 1943) is a retired American aerospace engineer and entrepreneur noted for his originality in designing light, strong, unusual-looking, and energy-efficient air and space craft. He designed the recor ...

to build the mothership and spacecraft. On January 23, 2008 the White Knight Two design was revealed. On July 28, 2008 the completion and rollout of the first aircraft, ''

Eve Eve is a figure in the Book of Genesis in the Hebrew Bible. According to the origin story, "Creation myths are symbolic stories describing how the universe and its inhabitants came to be. Creation myths develop through oral traditions and there ...

'', ( Tail Number: N348MS) occurred at Scaled's Mojave headquarters. Branson predicted that the maiden space voyage would take place in 18 months: "It represents... the chance for our ever-growing group of future astronauts and other scientists to see our world in a completely new light." On March 22, 2010 the VMS ''Eve'' completed its 25th flight, the first occasion it carried a SpaceShipTwo, VSS ''Enterprise''. In a flight of 2 hours 54 minutes, it ascended to an altitude of . The launch customer of White Knight Two was

, which was planned to have the first two units, and exclusive rights to the craft for the first few years.

Flight test program

An extensive flight test program of VMS ''Eve'', with nearly twenty flights between December 2008 and August 2009, was undertaken to validate the design and gradually expand the aircraft operating envelope. The flight tests were complete by September 2009, and testing with

began in early 2010.

Aircraft specifications

References

External links

BBC - In pictures: Space tourism jet

Video of White Knight Two being unveiled

Photos of Virgin Galactic’s White Knight Two unveiling

{{DEFAULTSORT:Scaled Composites Whiteknighttwo WK2 VMS WhiteKnightTwo White Knight Two WhiteKnightTwo Space tourism 2000s United States airliners Twin-fuselage aircraft 2000s United States special-purpose aircraft Rutan aircraft Quadjets Cruciform tail aircraft Aircraft first flown in 2008 Aircraft related to spaceflight Twin-tail aircraft Aircraft with retractable quad landing gear