Jump to content

SpaceShipTwo

From Wikipedia, the free encyclopedia

SpaceShipTwo
Picture of the SpaceShipTwo VSS Unity at the unveiling event in Mojave, California
SpaceShipTwo VSS Unity in the Virgin Galactic Final Assembly Integration Test Hangar
ManufacturerScaled Composites
(VSS Enterprise)
The Spaceship Company
(VSS Unity)
Country of originUnited States
OperatorVirgin Galactic
ApplicationsSuborbital space tourism
Specifications
Spacecraft typeCrewed spaceplane
Launch mass13,154 kg (29,000 lb)
Dry mass6,123 kg (13,500 lb)
Crew capacity8 (planned); 6 (actual)
Volume14 m3 (500 cu ft) pressurized
RegimeSuborbital
Dimensions
Length18.3 m (60 ft)
Height5.5 m (18 ft)
Width8.3 m (27 ft)
Capacity
Payload to Suborbital
Mass600 kg (1,300 lb)
Production
StatusRetired
Built2
Retired1 (VSS Unity)
Lost1 (VSS Enterprise)
Maiden launch10 October 2010 (glide flight)
29 April 2013 (powered flight)
13 December 2018 (spaceflight)
Related spacecraft
Derived fromSpaceShipOne
DerivativesSpaceShip III
Engine details
Powered by1 RocketMotorTwo engine
Maximum thrust310 kN (70,000 lbf)
Specific impulse250 s
PropellantNitrous oxide / Hydroxyl-terminated polybutadiene

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 carried to its launch altitude by a Scaled Composites White Knight Two, before being released to fly on into the upper atmosphere powered by its rocket engine. It then glided back to Earth and performed a conventional runway landing.[1] The spaceship was officially unveiled to the public on 7 December 2009 at the Mojave Air and Space Port in California.[2] On 29 April 2013, after nearly three years of unpowered testing, the first SS2 constructed successfully performed its first powered test flight.[3]

Virgin Galactic planned to operate a fleet of five SpaceShipTwo spaceplanes in a private passenger-carrying service[4][5][6][7] and took bookings for some time, with a suborbital flight carrying a ticket price of US$250,000 in 2015.[8] The spaceplane was also used to carry scientific payloads for NASA and other organizations.[9]

On 31 October 2014, during a test flight, the first SpaceShipTwo VSS Enterprise broke up in flight and crashed in the Mojave desert.[10][11][12][13] An investigation found that the craft's descent device deployed too early.[14][15] One pilot, Michael Alsbury, was killed; the other was treated for a serious shoulder injury after parachuting from the stricken spacecraft.[16][17]

The second SpaceShipTwo spacecraft, VSS Unity, was unveiled on 19 February 2016.[18][19] The vehicle underwent flight testing 2016-2023.[20][21][22] Its first flight to space (above 50 miles altitude), VSS Unity VP03, took place on 13 December 2018.[23][24] The first operational flight of Unity (defined as the first flight flying passengers that were not Virgin Galactic employees) was Galactic 01 on 29 June 2023. The final flight of Unity was Galactic 07 on 8 June 2024.

Design overview

[edit]

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 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 apogee of the new craft was designed to be approximately 110 km (68 mi) in the lower thermosphere, 10 km (6.2 mi) higher than the Kármán line but as of July 2021, the maximum height reached was 89.9 km.[25] In the end, the SpaceShipTwos never broke the 100 km limit. The predecessor craft SpaceShipOne's target was also 100 km but the last flight reached an altitude of 112 km (70 mi).[26] SpaceShipTwo was designed to reach 4,200 km/h (2,600 mph), using a single hybrid rocket engine — the RocketMotorTwo.[27] It launched from its mothership, White Knight Two, at an altitude of 13,500 m (44,300 ft),[28] 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 3.7 m (12 ft) long and 2.3 m (7 ft 7 in) in diameter.[29] The wing span was 8.2 m (27 ft), the length was 18 m (59 ft) and the tail height was 4.6 m (15 ft).[30]

SpaceShipTwo used a feathered reentry system, feasible due to the low speed of reentry. In contrast, orbital spacecraft re-enter at orbital speeds, close to 25,000 km/h (16,000 mph), using heat shields. SpaceShipTwo was furthermore designed to re-enter the atmosphere at any angle.[31] It decelerated through the atmosphere, switching to a gliding position at an altitude of 24 km (15 mi), 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 White Knight, which won the Ansari X Prize in 2004. SpaceShipTwo had 43 and 33 cm (17 and 13 in)-diameter windows for the passengers' viewing pleasure,[30] and all seats reclined back during landing to decrease the discomfort of G-forces.[32] In 2008, Burt Rutan remarked on the safety of the vehicle:

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.[31]

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.[33]

Fleet and launch sites

[edit]

Fleet history

[edit]

SpaceShipTwo (and the WhiteKnightTwo launcher aircraft) were built by The Spaceship Company, originally formed as a joint venture between Scaled Composites and Virgin Galactic.[34] Virgin Galactic bought out Scaled Composites' interest in TSC in 2012, and TSC became a wholly owned subsidiary of Virgin Galactic.[35]

The launch customer of SpaceShipTwo was Virgin Galactic, who as of 2005 had publicly announced they had ordered five vehicles,[36][37] but only three had been ordered by 2015.[38] The first SS2 was named VSS Enterprise.[39] The "VSS" prefix stands for "Virgin Space Ship". VSS Enterprise was the first to fly;[40] it was destroyed in a crash on 31 October 2014.[10][41][42] The build of VSS Unity was about 65% complete in early November 2014, and Virgin Galactic expected it to be complete in 2015. It was unveiled in February 2016[43] and performed its first powered flight in April 2018. The third SpaceShipTwo was expected to commence construction by the end of 2015.[38][21]

Unity was retired on 8 June 2024 after its final flight took place on that date, as Virgin Galactic shifted its focus to the next generation Delta-class vehicles. At the time, the only SpaceShipTwos completed and flown were the Enterprise and the Unity.[44]

Launch sites

[edit]

SpaceShipTwo was launched from the WhiteKnightTwo launcher aircraft, which took off from the Mojave Air and Space Port in California during testing. Spaceport America (formerly Southwest Regional Spaceport), a US$212 million spaceport in New Mexico, partly funded by the state government,[45] became the permanent launch site for the latter part of test flight programme and for commercial launches.[29]

Ships in class

[edit]
Ship Tail number First unpowered flight First powered flight First spaceflight Last flight Status
VSS Enterprise N339SS 10 October 2010 29 April 2013 n/a 31 October 2014 Destroyed[10][41][42]
VSS Unity N202VG 3 December 2016 [20] 5 April 2018 13 December 2018 8 June 2024 Retired

Two further ships were under construction by 2016.[38][46][47] It is unclear whether these are now designated to be SpaceShip III class vehicles. As of 2024, the only SpaceShipTwo-class vehicles completed and flown are Enterprise and Unity.

Development

[edit]
Full-scale mock-up of SpaceShipTwo in Virgin Galactic livery

On 28 September 2006, Virgin Group founder Sir Richard Branson unveiled a mock-up of the SpaceShipTwo passenger cabin at the NextFest exposition at the Jacob K. Javits Convention Center in New York.[48] The design of the vehicle was revealed to the press in January 2008, with the statement that the vehicle itself was around 60% complete.[29] On 7 December 2009, the official unveiling and rollout of SpaceShipTwo took place. The event involved the first SpaceShipTwo being christened by then - Governor of California Arnold Schwarzenegger as the VSS Enterprise.[49]

2007 test explosion

[edit]

On 26 July 2007, an explosion occurred during an oxidizer flow test at the Mojave Air and Space Port, where early-stage tests were being conducted on SpaceShipTwo's systems. The oxidizer test included filling the oxidizer tank with 4,500 kg (9,900 lb) of nitrous oxide, followed by a 15-second cold-flow injector test. Although the tests did not ignite the gas, three employees were killed and three injured by flying shrapnel.[50]

Rocket engine

[edit]

The hybrid rocket engine design for SpaceShipTwo was problematic and caused extensive delays to the flight test program. The original rocket engine design was based on hydroxyl-terminated polybutadiene (HTPB) fuel and nitrous oxide oxidizer, sometimes referred to as an N2O/HTPB engine.[51][52] It was developed by Scaled Composites subcontractor Sierra Nevada Corporation (SNC) from 2009 to early 2014. In May 2014, Virgin Galactic announced a change to the hybrid engine to be used in SpaceShipTwo, and took the development effort in-house to Virgin Galactic, terminating the contract with Sierra Nevada and halting all development work on the first-generation rocket engine.[53] Virgin then modified the engine design to include a change of the hybrid rocket fuel from a HTPB to a polyamide fuel formulation. In October 2015, Virgin announced that it was considering changing back to the original HTPB fuel.[54]

2014 change of engine

[edit]

Rather than the rubber-based HTPB-fuel engine—engines that had experienced serious engine stability issues on firings longer than approximately 20 seconds — the engine would instead be based on a solid fuel composed of a type of plastic called thermoplastic polyamide. The plastic fuel was projected to have better performance (by several unspecified measures) and was projected to allow SpaceShipTwo to make flights to a higher altitude.[55][56][57]

As of May 2014 when the version 2 engine by Virgin Galactic was publicly announced, the engine had already completed full-duration burns of over 60 seconds in ground tests on an engine test stand.[56] The second-generation engine design also required the modification to the SS2 airframe to fit additional tanks in the wings of SpaceShipTwo — one holding methane and the other containing helium — in order to ensure a proper burn and shut-down of the new engine.[58] Additional ground tests were performed on the new engine between May and October 2014.

2015: another fuel change

[edit]

Following a series of rocket engine tests, Virgin announced in October 2015 that they would be changing the rocket motor back to hydroxyl-terminated polybutadiene (HTPB), with a similar formulation as they used earlier in the development program before switching to a nylon-based fuel grain. They would use HTPB to power the SpaceShipTwo when it would resume flight following the loss of the initial SS2 test vehicle in October 2014. Full qualification tests remained to be completed at the time.[59]

RocketMotorTwo

[edit]

The second-generation RocketMotorTwo engine was a variant of the earlier SNC basic design, but was fueled by polyamide plastic fuel, while continuing to use the same nitrous oxide oxidizer. The second-generation engine was made in-house by Virgin Galactic rather than by SNC. By December 2012, 15 full-scale tests had been successfully conducted,[60][61] and additional ground tests continued into March 2013.[62] In June 2012, the Federal Aviation Administration (FAA) issued a rocket testing permit to Scaled Composites, allowing it to begin SS2 test flights powered by RocketMotorTwo;[63] the first such powered flight took place on 29 April 2013.[64] The engine produced 270 kN (61,000 lbf) of thrust.

Test flights

[edit]
SpaceShipTwo in a captive flight configuration underneath White Knight Two, during the runway dedication of Spaceport America in October 2010. VMS Eve is shown carrying VSS Enterprise.
A view of the firing of SpaceShipTwo's rocket engines during its first powered flight in April 2013.

Testing VSS Enterprise

[edit]

In September 2012, Virgin Galactic announced that the unpowered subsonic glide flight test program was essentially complete.[65] In October 2012, Scaled Composites installed key components of the rocket engine, and SpaceShipTwo performed its first glide flight with the engine installed in December 2012.[66][67]

The spacecraft's first powered test flight took place on 29 April 2013. SpaceshipTwo reached supersonic speeds in this first powered flight.[68][69] On 5 September 2013, the second powered flight was made by SpaceShipTwo.[70] The first powered test flight of 2014 — and third overall — occurred 10 January 2014. The spacecraft reached an altitude of 22,000 m (72,000 ft) and a speed of Mach 1.4 (1,720 km/h; 1,070 mph). The WhiteKnightTwo carrier aircraft released SpaceShipTwo (VSS Enterprise) at an altitude of 14,000 m (46,000 ft).[71]

October 2014 crash

[edit]
NTSB Go-Team inspects a tail section of VSS Enterprise.

On 31 October 2014, SpaceShipTwo VSS Enterprise suffered an in-flight breakup during a powered flight test,[72][73] resulting in a crash killing one pilot, Michael Alsbury, and injuring the other.[10][17] It was coincidentally the first flight to use the new type of fuel, based on nylon plastic grains.[74][75] The crash was caused by a premature deployment of the feathering mechanism, which was normally used to aid in a safe descent. SpaceShipTwo was still in powered ascent when the feathering mechanism deployed. Disintegration was observed two seconds later.[73]

As of October 2014, SpaceShipTwo had conducted 54 test flights.[76] The spacecraft had used its "feathered" wing configuration during ten of these test flights.[76][77][78]

The National Transportation Safety Board conducted an independent investigation into the accident. In July 2015, the NTSB released a report which cited inadequate design safeguards, poor pilot training, lack of rigorous federal oversight and a potentially anxious co-pilot as important factors in the 2014 crash.[79][80] While the co-pilot was faulted for prematurely deploying the ship's feathering mechanism, the Federal Aviation Administration, Federal Aviation Administration Office of Commercial Space Transportation, and the ship's designers were also faulted for not creating a fail-safe system that could have guarded against such premature deployment.[80]

VSS Unity

[edit]

In October 2015, it was reported that the second SpaceShipTwo would make its first flight in 2016.[81] VSS Unity was unveiled in February 2016.

A phase of testing called "Integrated Vehicle Ground Testing" began on VSS Unity in February 2016.[21] Between 8 September and 30 November 2016, Virgin Galactic conducted a series of captive-carry flights of Unity, including planned glide flights (1 and 3 November 2016) for which the glide portion of the flight was cancelled because of wind speed.[82][83][84][85] Glide flights of Unity began on 3 December 2016.[86][87][88][89]

After several glide flights over the preceding months, in July 2017, Richard Branson suggested that the craft was to begin powered tests at three-week intervals.[90] In September 2017, CEO George Whitesides suggested that engine testing was complete, and that only a "small number of glide flights" remained before VSS Unity would begin powered tests flights.[91] In October 2017, Branson suggested that SpaceShipTwo could reach space within three months, and that he could travel to space aboard a SpaceShipTwo within six months.[92][93] A seventh high speed glide test was completed in January 2018.[94] On 13 December 2018, SpaceShipTwo VSS Unity reached its highest altitude up to that point, 82.72 km (51.40 mi). This surpassed the U.S. Government definition of space at 80 km (50 mi) but not the standard used elsewhere at 100 km (62 mi).[95] Despite the debate on where outer space begins, Mark Stucky would receive his astronaut wings, while Frederick W. Sturckow would not as he had already flown on the Space Shuttle four times.[23]

Following a February 2019 spaceflight, VSS Unity began to undergo modifications in preparation for commercial service; this includes an upgrading the flight deck and installing a passenger cabin.[96] It was later revealed in 2021 that VSS Unity had actually suffered a large crack in its structure during its 2019 spaceflight, requiring repair work to the vehicle.[97] Following its return to service VSS Unity made a test flight that included Richard Branson as a passenger on July 11, 2021. During this flight, the vehicle deviated from its planned flight course triggering a Federal Aviation Administration investigation into the issue. While in ascent the vehicle triggered a red warning light which indicated it had deviated from its safe flight path.[98] On 2 September 2021, it was publicly announced that further SpaceShipTwo flight tests would be grounded by FAA mandate until the investigation was completed.[99] The FAA cleared SpaceShipTwo flights to resume later in September, after deciding to expand the restricted aerospace around the vehicle's flight range.[100]

The final test flight (defined as final flight with only Virgin Galactic personnel onboard) was Virgin Galactic Unity 25 mission on 25 May 2023. The first operational flight of Unity (defined as the first flight flying passengers that were not Virgin Galactic employees) was Galactic 01 on 29 June 2023.

SpaceShipTwo spaceflights (above 50 miles)
Spaceflight Date Outcome Top speed Altitude Crew
VSS Unity VP-03 13 December 2018 Success Mach 2.9 [101] 82.72 km (51.40 mi) Mark P. Stucky and Frederick W. Sturckow
VSS Unity VF-01 22 February 2019 Success Mach 3.04 [102] 89.9 km (55.9 mi) [103] Dave Mackay, Michael Masucci, and Beth Moses (passenger)
VSS Unity VF-02 12 December 2020, 16:15 UTC (aborted)[104] Aborted prior to ignition N/A N/A Dave Mackay and Frederick W. Sturckow[105]
VSS Unity Unity 21 22 May 2021, 15:26 UTC Success Mach 3 89.2 km (55.4 mi) Dave Mackay and Frederick W. Sturckow[106]
VSS Unity Unity 22 11 July 2021 Success TBD 86 km (53 mi) [107] David Mackay, Michael Masucci, Sirisha Bandla, Colin Bennett, Beth Moses, and Sir Richard Branson
VSS Unity Unity 25 25 May 2023, 16:23 UTC[108] Success Mach 2.94 87.2 km (54.2 mi) Michael Masucci, Frederick W. Sturckow, Beth Moses, Luke Mays, Jamila Gilbert, Christopher Huie
Galactic 01 27 June 2023, 15:28 UTC[109] Success Mach 2.88 85.1 km (52.9 mi) Michael Masucci, Nicola Pecile, Walter Villadei, Angelo Landolfi, Pantaleone Carlucci and Colin Bennett
Galactic 02 10 August 2023, 15:17 UTC[110] Success Mach 3.00 88.5 km (55.0 mi) CJ Sturckow, Kelly Latimer, Beth Moses, Jon Goodwin, Keisha Schahaff, Anastatia Mayers
Galactic 03 8 September 2023, 15:22 UTC[111] Success Mach 2.95 88.6 km (55.1 mi) Michael Masucci, Nicola Pecile, Beth Moses, Timothy Nash, Ken Baxter, Adrian Reynard[112]
Galactic 04 6 October 2023, 16:10 UTC[113] Success Mach 2.95 87.4 km (54.3 mi) Kelly Latimer, CJ Sturckow, Beth Moses, Ron Rosano, Trevor Beattie, Namira Salim
Galactic 05 2 November 2023, 15:44 UTC[114] Success Mach 2.96 87.2 km (54.2 mi) Michael Masucci, Kelly Latimer, Colin Bennett, Alan Stern, Kellie Gerardi, Ketty Maisonrouge
Galactic 06 26 January 2024, 17:42 UTC[115] Success Mach 2.98 88.8 km (55.2 mi) CJ Sturckow, Nicola Pecile, Lina Borozdina, Robie Vaughn, Franz Haider, Neil Kornswiet
Galactic 07 8 June 2024, 15:26:30 UTC[116] Success Mach 2.96 88.75 km (55.15 mi) Nicola Pecile, Jameel Janjua, Tuva Cihangir Atasever, Andy Sadhwani, Irving Pergament, Giorgio Manenti

Costs

[edit]

SpaceShipTwo's total development costs were estimated at around US$400 million in May 2011, a significant increase over the 2007 estimate of US$108 million.[117]

Commercial operation

[edit]
Timeline of Space­Ship­One, Space­Ship­Two, CSXT and New Shepard sub-orbital flights. Where booster and capsule achieved different altitudes, the higher is plotted. In the SVG file, hover over a point to show details.

The duration of the flights was expected to be approximately 2.5 hours, although only a few minutes of that was to be in space. The price was initially US$200,000.[118] More than 65,000 would-be space tourists applied[when?] for the first batch of 100 tickets. By December 2007, Virgin Galactic had 200 paid-up customers on its books for the early flights, and 95% were passing the 6-8 g centrifuge tests.[119] That number had increased to 575 by early 2013.[120]

In April 2013, Virgin Galactic announced that the price for a seat would increase 25% to US$250,000 before the middle of May 2013,[120] and would remain at US$250,000 "until the first 1,000 people have traveled, so that it matches up with inflation since [Virgin Galactic] started".[121]

The first paying customers had been expected to fly aboard the craft in 2014, following 50–100 test flights.[4] Refining the projected schedule in late 2009, Virgin Galactic declined to announce a firm timetable for commercial flights, but did reiterate that initial flights would take place from Spaceport America. Operational roll-out would be based on a "safety-driven schedule".[122]

In addition to making suborbital passenger launches, Virgin Galactic marketed SpaceShipTwo for suborbital space science missions.[122]

NASA sRLV program

[edit]

By March 2011, Virgin Galactic had submitted SpaceShipTwo as a reusable launch vehicle for carrying research payloads in response to NASA's suborbital reusable launch vehicle (sRLV) solicitation, which was a part of the agency's Flight Opportunities Program. Virgin projected research flights might reach a peak altitude of 110 km (68 mi). These flights would provide approximately four minutes of microgravity for research payloads. Payload mass and microgravity levels had not been specified at the time.[1] Since May 2021, NASA-supported technology and systems have been tested on SpaceShipTwo.[123]

Future spacecraft

[edit]

In August 2005, the president of Virgin Galactic stated that if the suborbital service with SpaceShipTwo would be successful, the follow-up SpaceShipThree would be an orbital craft. In 2008, Virgin Galactic suggested that it may develop a high-speed passenger vehicle to offer transport through point-to-point suborbital spaceflight.[124]

Specifications

[edit]

Data from Virgin Galactic,[125] space.com[126] & Popular Mechanics[127]

General characteristics

  • Crew: 2
  • Capacity: 6 passengers
  • Length: 18.3 m (60 ft 0 in)
  • Wingspan: 8.3 m (27 ft 3 in)
  • Height: 5.5 m (18 ft 1 in)
  • Gross weight: 9,740 kg (21,473 lb)
  • Powerplant: 1 × RocketMotorTwo liquid/solid hybrid rocket engine

Performance

  • Maximum speed: 4,000 km/h (2,500 mph, 2,200 kn)
  • Service ceiling: 110,000 m (360,000 ft)

See also

[edit]

References

[edit]
  1. ^ a b "sRLV platforms compared". NASA. 7 March 2011. Archived from the original on 20 February 2021. Retrieved 10 March 2011. SpaceShipTwo: Type: HTHL/Piloted Public Domain This article incorporates text from this source, which is in the public domain.
  2. ^ Amos, Jonathan (8 December 2009). "Richard Branson unveils Virgin Galactic spaceplane". BBC News. Retrieved 23 March 2010.
  3. ^ "Sir Richard Branson's Virgin Galactic spaceship ignites engine in flight". BBC News. 29 April 2013. Retrieved 29 April 2013.
  4. ^ a b "Space Ship Completes 24th Test Flight in Mojave". Hispanic Business. 4 April 2013. Archived from the original on 30 December 2013. Retrieved 5 April 2013.
  5. ^ "Virgin Galactic to Launch Passengers on Private Spaceship in 2013". SPACE.com. 8 June 2012. Retrieved 11 June 2012.
  6. ^ ""Virgin Galactic space tourism could begin in 2013"". BBC News. 26 October 2011.
  7. ^ John Schwartz (23 January 2008). "New Tourist Spacecraft Unveiled". The New York Times. Retrieved 23 January 2008.
  8. ^ Fly With Us Archived 12 November 2015 at the Wayback Machine Virgin Galactic Retrieved 5 November 2015
  9. ^ "Virgin spaceship aims to be science lab". BBC News. 4 December 2012. Retrieved 4 December 2012.
  10. ^ a b c d Chang, Kenneth; Schwartz, John (31 October 2014). "Virgin Galactic's SpaceShipTwo Crashes in New Setback for Commercial Spaceflight". The New York Times. Retrieved 1 November 2014.
  11. ^ Foust, Jeff (31 October 2014). "SpaceShipTwo Destroyed in Fatal Test Flight Accident". SpaceNews. Archived from the original on 31 October 2014. Retrieved 31 October 2014.
  12. ^ "Virgin Galactic's SpaceShipTwo Crashes During Flight Test". NBC News. 31 October 2014.
  13. ^ Durden, Rick (31 October 2014). "Virgin Galactic's SpaceShipTwo Crashes". AVweb. Archived from the original on 14 April 2020. Retrieved 31 October 2014.
  14. ^ Chang, Kenneth (3 November 2014). "Investigators Focus on Tail Booms in Crash of Space Plane". The New York Times. Retrieved 3 November 2014.
  15. ^ Melley, Brian (3 November 2014). "Spaceship's descent device deployed prematurely". Associated Press. Retrieved 3 November 2014.
  16. ^ Klotz, Irene (3 November 2014). "SpaceShipTwo's Rocket Engine Did Not Cause Fatal Crash". Discovery News. Archived from the original on 16 December 2014. Retrieved 3 November 2014.
  17. ^ a b "Virgin Galactic's SpaceShipTwo rocket plane crashes". 31 October 2014.
  18. ^ "New SpaceShipTwo Rollout Friday". AVweb. 18 February 2016. Archived from the original on 22 March 2016. Retrieved 19 February 2016.
  19. ^ "Virgin Galactic unveils new space tourism rocket plane". CBC News. 19 February 2016. Retrieved 20 February 2016.
  20. ^ a b Weston Williams (5 December 2016). "Space tourism: Virgin Galactic makes successful glide test". Christian Science Monitor. Retrieved 5 December 2015.
  21. ^ a b c "Update from Mojave: Testing Testing 1-2-3". Virgin Galactic. 10 March 2016. Archived from the original on 15 March 2016. Retrieved 15 March 2016.
  22. ^ "Update from Mojave: VSS Unity's First Flight Test Completed - Virgin Galactic". virgingalactic.com. 9 September 2016. Archived from the original on 12 September 2016. Retrieved 12 September 2016.
  23. ^ a b Wattles, Jackie (14 December 2018). "Virgin Galactic reaches 50-mile space". edition.cnn.
  24. ^ Grush, Lauren (13 December 2018). "Virgin Galactic's spaceplane finally makes it to space for the first time". The Verge. Retrieved 13 December 2018.
  25. ^ "Virgin's Unity plane rockets skyward". BBC. 22 February 2019.
  26. ^ "SpaceShipOne Flight Tests". Scaled Composites. Archived from the original on 22 August 2010.
  27. ^ "Project Test Summaries". Scaled Composite. Archived from the original on 22 February 2014. Retrieved 5 April 2012.
  28. ^ "Replay! Virgin Galactic's 2nd commercial crew spaceflight with VSS Unity - Full Broadcast". 10 August 2023 – via www.youtube.com.
  29. ^ a b c Rob Coppinger. "Pictures: Virgin Galactic unveils Dyna-Soar style SpaceShipTwo design and twin-fuselage White Knight II configuration". Flightglobal. Retrieved 23 January 2008.
  30. ^ a b "Spaceship Unveil Presspack". Virgin Galactic. Archived from the original on 16 February 2008. Retrieved 10 February 2008.
  31. ^ a b Dignan, Larry (23 January 2008). "Virgin Galactic unveils SpaceShipTwo; Plans open architecture spaceship". ZDnet.com. Archived from the original on 6 December 2013. Retrieved 10 February 2008.
  32. ^ Tariq Malik (28 September 2006). "Virgin Galactic Unveils SpaceShipTwo Interior Concept". SpaceNews. Retrieved 6 April 2007.
  33. ^ "Virgin Galactic's private spaceship makes safe landing after tense test flight" SPACE.com 17 October 2011 Retrieved 18 October 2011
  34. ^ Norris, Guy (11 July 2011). "Scaled And Virgin Lift Veil on Spaceship Production Progress". Aviation Week & Space Technology. Retrieved 8 July 2011.
  35. ^ "Virgin Galactic Acquires Full Ownership of The Spaceship Company". Business Wire. 5 October 2012. Retrieved 6 October 2012.
  36. ^ "Richard Branson and Burt Rutan Form Spacecraft Building Company". SPACE.com. 27 July 2005. Retrieved 17 October 2009.
  37. ^ Malik, Tariq (23 January 2008). "Virgin Galactic Unveils Suborbital Spaceliner Design". SPACE.com. Retrieved 25 January 2008.
  38. ^ a b c "Virgin Galactic Gears Up for Building Third SpaceShipTwo". NBC News. 7 February 2015.
  39. ^ "Virgin Galactic to Offer Public Space Flights". SPACE.com. 27 September 2004. Retrieved 20 December 2007.
  40. ^ "Scale comparison chart of Spaceshipone and Spaceshiptwo". Gizmodo. Archived from the original on 17 March 2007. Retrieved 6 April 2007.
  41. ^ a b Rogers, Adam (31 October 2014). "Space Tourism Isn't Worth Dying For". Wired (magazine). Retrieved 1 November 2014.
  42. ^ a b "Virgin Galactic spacecraft crash kills pilot". BBC News. 31 October 2014. Retrieved 8 November 2014.
  43. ^ "Virgin Galactic CEO Sees New Spacecraft Ready Next Year". Newsweek. 2 November 2014.
  44. ^ Foust, Jeff (8 May 2024). "Virgin Galactic plans higher mothership flight rate with next-generation spaceplanes". SpaceNews. Retrieved 9 May 2024.
  45. ^ New era draws closer: Spaceport dedicates runway on New Mexico ranch Archived 10 December 2012 at archive.today El Paso Times 23 October 2010 Retrieved 25 October 2010 "two-thirds of the US$212 million required to build the spaceport came from the state of New Mexico... The rest came from construction bonds backed by a tax approved by voters in Doña Ana and Sierra counties".
  46. ^ "Second Spaceship in Virgin Galactic's fleet completes major build milestone". Space Daily. 10 January 2020. Retrieved 11 January 2020.
  47. ^ "Virgin Galactic unveils the new SpaceShip Two, named the VSS Unity". Engadget. 19 February 2016. Retrieved 20 February 2016. The plans for this ship are for it to be the first Virgin Galactic ship that takes paid passengers to space, and the third and fourth ships are already under construction.
  48. ^ Sophie Morrison (30 September 2006). "Buckled up for white knuckle ride". BBC News. Retrieved 6 April 2007.
  49. ^ Richard Branson unveils Virgin Galactic spaceplane BBC News 7 December 2009
  50. ^ Abdollah, Tami and Silverstein, Stuart (27 June 2007) "Test Site Explosion Kills Three" Los Angeles Times Retrieved 27 July 2007
  51. ^ "Propulsion Systems: multiple-burn, green and low-cost" (PDF). Sierra Nevada. Archived from the original (PDF) on 23 March 2014. Retrieved 8 March 2013.
  52. ^ "Safe Hybrid Rocket". Virgin Galactic. 2013. Archived from the original on 4 March 2013. Retrieved 8 March 2013.
  53. ^ "SNC Statement in Response to Inquiries Regarding 31 October 2014 Virgin Galactic SpaceShipTwo Incident". Sierra Nevada Corporation. 31 October 2014. Archived from the original on 1 November 2014. Retrieved 1 November 2014.
  54. ^ Foust, Jeff (14 October 2015). "SpaceShipTwo Bounces Back to Rubber Fuel". SpaceNews. Retrieved 16 October 2015.
  55. ^ Foust, Jeff (24 May 2014). "Virgin Galactic changes fuels as it prepares for its next round of test flights". NewSpace Journal. Retrieved 25 May 2014.
  56. ^ a b Boyle, Alan (23 May 2014). "Virgin Galactic Makes a Switch in SpaceShipTwo's Rocket Motor". NBC News. Retrieved 24 May 2014.
  57. ^ Morris, Guy (24 May 2014). "New Fuel to Boost SpaceShip Two". Aviation Week. Retrieved 10 December 2015.
  58. ^ Messier, Doug (30 June 2014). "WhiteKnightTwo in the Air Over Mojave Today". Parabolic Arc. Retrieved 1 November 2014.
  59. ^ SpaceShipTwo Bounces Back to Rubber Fuel SpaceNews, 14 October 2015, accessed 26 November 2015
  60. ^ RocketMotorTwo Hot-Fire Test Summaries Archived 26 April 2012 at the Wayback Machine Scaled.com Updated 9 August 2012 Retrieved 16 December 2012
  61. ^ "Virgin Galactic successfully completes SpaceShipTwo glide flight test and rocket motor firing on same day" Archived 28 July 2020 at the Wayback Machine SpaceRef 28 June 2012
  62. ^ "This isn't sci-fi". Virgin.com. 5 March 2013. Archived from the original on 7 March 2013. Retrieved 5 March 2013.
  63. ^ "SpaceShipTwo Gets Thumbs Up for Rocket-Powered Flights". Flying Magazine. 1 June 2012.
  64. ^ "SpaceShipTwo Test Summaries". Scaled Composites. 29 April 2013. Archived from the original on 16 August 2013. Retrieved 29 April 2013.
  65. ^ Rosenberg, Zach; "Virgin Galactic finishes unpowered flight test" FlightGlobal 13 September 2012 Retrieved 26 September 2012
  66. ^ "SpaceShipTwo straps on its engine". NBC News. 20 December 2012. Retrieved 20 December 2012.
  67. ^ "SpaceShipTwo Fitted With Rocket Propulsion System". Aviation Week. 22 October 2012. Archived from the original on 12 October 2013. Retrieved 14 November 2012.
  68. ^ "SpaceShipTwo Test Summaries". Scaled Composites. 8 August 2013. Archived from the original on 16 August 2013. Retrieved 14 August 2013.
  69. ^ "Virgin Galactic Breaks Speed of Sound in First Rocket-Powered Flight of SpaceShipTwo". Virgin Galactic. 29 April 2013. Archived from the original on 30 April 2013. Retrieved 29 April 2013.
  70. ^ "Virgin Galactic's SpaceShipTwo Succeeds in Second Rocket-Powered Flight". Forbes. Retrieved 6 September 2013.
  71. ^ Nancy Atkinson (10 January 2014). "SpaceShipTwo Goes Supersonic in Third Rocket-Powered Test Flight". Universe Today.
  72. ^ "SpaceShipTwo disaster: Industry mourns pilot but vows to keep ..." The Bakersfield Californian. Archived from the original on 23 October 2015.
  73. ^ a b "SpaceShipTwo 'Feather' Tail System Deployed Prematurely: NTSB". NBC News. 3 November 2014.
  74. ^ Marks, Paul. "Virgin Galactic's Spaceshiptwo in fatal crash". newscientist.com. New Scientist. Retrieved 1 November 2014.
  75. ^ "Virgin Galactic's SpaceShipTwo Has Crashed, Possible Casualties". Gizmodo. 31 October 2014. Retrieved 31 October 2014.
  76. ^ a b Wall, Mike (8 October 2014). "Virgin Galactic's SpaceShipTwo Aces Glide Test Flight". SPACE.com. Retrieved 8 October 2014.
  77. ^ "Feather flight and nitrous vent test success". Virgin Galactic. Archived from the original on 11 November 2019. Retrieved 12 April 2013.
  78. ^ "Virgin Galactic Reaches New Heights in Third Supersonic Test Flight". virgingalactic.com. 10 January 2014. Archived from the original on 7 April 2014. Retrieved 13 January 2014.
  79. ^ "In-Flight Breakup During Test Flight, Scaled Composites SpaceShipTwo, N339SS, Near Koehn Dry Lake, California, October 31, 2014" (PDF). National Transportation Safety Board. 28 July 2015. Retrieved 29 August 2017.
  80. ^ a b "Lack of Consideration for Human Factors Led to In-Flight Breakup of SpaceShipTwo". NTSB. 28 July 2015. Retrieved 29 July 2015. Public Domain This article incorporates text from this source, which is in the public domain.
  81. ^ "Virgin Galactic's New SpaceshipTwo Nearing Completion as Return to Flight Tests Push to 2016". AmericaSpace. 9 October 2015. Retrieved 20 February 2016.
  82. ^ Tariq Malik (1 November 2016). "Virgin Galactic Postpones 1st Glide Test with New SpaceShipTwo". Retrieved 4 November 2016.
  83. ^ "Virgin Galactic looks to next SpaceShipTwo glide test". inverse.com. 4 November 2016. Retrieved 5 November 2016.
  84. ^ "Last Minute Scrub of SpaceShipTwo Glide Flight". Parabolic Arc. 4 November 2016. Archived from the original on 5 April 2023. Retrieved 5 November 2016.
  85. ^ "Virgin Galactic conducts captive carry flight of SpaceShipTwo". Spaceflight Insider. 1 December 2016. Archived from the original on 4 April 2023. Retrieved 5 December 2016.
  86. ^ "Virgin Galactic spaceship makes first glide flight". phys.org. 3 December 2016. Retrieved 5 December 2016.
  87. ^ David Millward (4 December 2016). "Virgin Galactic's space programme moves forward as SpaceShipTwo carries out first successful glide test". telegraph.co.uk. Retrieved 5 December 2016.
  88. ^ Weston Williams (5 December 2016). "Space tourism: Virgin Galactic makes successful glide test". Christian Science Monitor. Retrieved 5 December 2016.
  89. ^ "Update from Mojave: Successful First Glide Flight Test for VSS Unity". virgingalactic.com. 3 December 2016. Archived from the original on 13 May 2017. Retrieved 6 December 2016.
  90. ^ "Branson Aims Mid-2018 Space Trip as Virgin Resumes Powered Tests". Bloomberg. 5 July 2017. Retrieved 8 July 2017.
  91. ^ "Virgin Galactic is returning to powered flights, CEO says, in a crucial next step for the spaceship company". CNBC. 7 September 2017. Retrieved 8 September 2017.
  92. ^ "Virgin Galactic founder says spaceflights could be months away". KOB. 9 October 2017. Archived from the original on 14 October 2017. Retrieved 13 October 2017.
  93. ^ Klotz, Irene (12 October 2017). "Virgin Galactic Hopes To Test SpaceShipTwo In Space In 2017". aviationweek.com. Retrieved 13 October 2017.
  94. ^ January 2018, Mike Wall 11 (11 January 2018). "Virgin Galactic's VSS Unity Soars on 7th Glide Flight (Photo)". SPACE.com. Retrieved 26 March 2021.{{cite web}}: CS1 maint: numeric names: authors list (link)
  95. ^ "A brief history of space". iop.org. Retrieved 13 December 2018.
  96. ^ Foust, Jeff (19 April 2019). "Virgin Galactic expects rapid conclusion of SpaceShipTwo test flights after downtime". spacenews.com. Retrieved 19 April 2019.
  97. ^ Berger, Eric (2 May 2021). "Will Virgin Galactic ever be successful? A new book offers insights". arstechnica.com. Retrieved 2 May 2021.
  98. ^ Schmidle, Nicholas (1 September 2021). "The Red Warning Light on Richard Branson's Space Flight". New Yorker.
  99. ^ Shepardson, David (2 September 2021). "U.S. bars Virgin Galactic rocket plane flights pending mishap probe". Reuters.
  100. ^ Foust, Jeff (29 September 2021). "FAA clears Virgin Galactic to resume SpaceShipTwo flights". Spacenews.
  101. ^ @virgingalactic (13 December 2018). "We travelled at 2.9 Mach on the way up to today. That's 2.9 times the speed of sound" (Tweet) – via Twitter.
  102. ^ @virgingalactic (22 February 2019). "Mach 3.0" (Tweet) – via Twitter.
  103. ^ [1][dead link]
  104. ^ "Virgin Galactic Update on Test Flight Program". Archived from the original on 11 July 2021. Retrieved 4 July 2021.
  105. ^ "VSS Unity aborts after engine start, safely lands with crew back at Spaceport America". 12 December 2020. Retrieved 23 May 2021.
  106. ^ "Virgin Galactic successfully makes first human spaceflight from New Mexico". 22 May 2021. Retrieved 23 May 2021.
  107. ^ Spaceflight Now on Twitter: Virgin Galactic’s VSS Unity rocketplane reached an apogee of 282,000 feet after a good burn of its hybrid rocket motor.
  108. ^ "Virgin Galactic is GO for launch". Virgin Galactic (Press release). 17 May 2023. Retrieved 19 May 2023.
  109. ^ Jonathan McDowell [@planet4589] (29 June 2023). "Galactic 01 stats: launch 1528:38 UTC, apogee 85.1 km, flight time from drop to main gear touchdown 13m50s. Drop location EBR P3 in my launch points list (107.0W 33.3N)" (Tweet) – via Twitter.
  110. ^ Jonathan McDowell [@planet4589] (10 August 2023). "I don't quite agree with these numbers. I have takeoff of White Knight 2 at 1429:45 UTC (in agreement with their 8.30 am MDT) but landing of SS2 at 1532:48 UTC (9.32 am MDT). Release time 1517:10 UTC and SS2 free flight time 15:38 with apogee 88.5 km" (Tweet) – via Twitter.
  111. ^ Jonathan McDowell [@planet4589] (8 September 2023). "Virgin Galactic few Spaceship Two mission Galactic 03 on Sep 8. VMS Eve took off at 1434 UTC and dropped VSS Unity over the usual drop point (EBR P3 in my list) at about 1522:13 UTC. Unity boosted to 88.6 km apogee and landed at Spaceport America at 1535 UTC" (Tweet) – via Twitter.
  112. ^ "Core memory unlocked. Welcome to space, #Galactic03. Congratulations, 014, 015, and 016!". X (formerly Twitter). Retrieved 8 September 2023.
  113. ^ "Virgin Galactic completes fifth successful flight in five months". Virgin Galactic (Press release). 6 October 2023. Retrieved 7 October 2023.
  114. ^ "'Galactic 05' research mission set to become Virgin Galactic's sixth flight in six months". Virgin Galactic (Press release). 18 October 2023. Retrieved 19 October 2023.
  115. ^ Jonathan McDowell [@planet4589] (26 January 2024). "The @VirginGalactic Galactic 06 mission was launched from the WK02 carrier plane at 1742:05 UTC Jan 26 following takeoff around 1700 UTC. After a one minute rocket burn, SS2 reached an apogee of 88.8 km and landed after an approximately 14 minute free flight. (1/2)" (Tweet) – via Twitter.
  116. ^ Jonathan McDowell [@planet4589] (8 June 2024). "Galactic 07 was dropped and fired its rocket engine at about 1526:30 UTC and landed at around 1541 UTC. Apogee not yet known" (Tweet) – via Twitter.
  117. ^ "A Look at Cost Overuns and Schedule Delays in Major Space Programs". Parabolic Arc. 4 May 2011. Retrieved 1 April 2012.
  118. ^ "Rich Chinese buying tickets to space". Zee News. Retrieved 6 April 2007.
  119. ^ "Virgin Galactic's timetable for progress" Spaceflight Volume 50 British Interplanetary Society February 2008 p. 48
  120. ^ a b Messier, Doug (29 April 2013). "Reserve Your SpaceShipTwo Seat Now – Big Price Increase Coming Soon". Parabolic Arc. Archived from the original on 15 December 2018. Retrieved 30 April 2013.
  121. ^ Wall, Mike (30 April 2013). "Ticket Price for Private Spaceflights on Virgin Galactic's SpaceShipTwo Going Up". SPACE.com. Retrieved 10 December 2015.
  122. ^ a b Will Whitehorn (27 October 2009). International Astronautical Congress 2009: Civilian Access to Space (Video – comments at c. 20:00). Daejeon, South Korea: Flightglobal Hyperbola. Retrieved 19 June 2013.
  123. ^ Newton, Laura (11 February 2021). "NASA-supported Tech to Fly on Virgin Galactic's SpaceShipTwo". NASA. Retrieved 26 March 2021. Public Domain This article incorporates text from this source, which is in the public domain.
  124. ^ "SpaceShipThree poised to follow if SS2 succeeds". Flight International. 23 August 2005. Retrieved 6 April 2007.
  125. ^ Overview – Spaceships Archived 22 July 2011 at the Wayback Machine Virgin Galactic Retrieved 19 June 2013
  126. ^ "How Virgin Galactic's SpaceShipTwo Passenger Space Plane Works (Infographic)". SPACE.com. 10 October 2012. Retrieved 14 November 2012.
  127. ^ Bennett, Jay (5 April 2018). "Virgin Galactic Conducts First Rocket-Powered Flight of VSS Unity". Popular Mechanics. Retrieved 13 December 2018.
[edit]