VSS Enterprise (tail number: N339SS[1]) was the first SpaceShipTwo (SS2) spaceplane, built by Scaled Composites for Virgin Galactic. As of 2004, it was planned to be the first of five commercial suborbital SS2 spacecraft planned by Virgin Galactic.[2][3][needs update] It was also the first ship of the Scaled Composites Model 339 SpaceShipTwo class, based on upscaling the design of record-breaking SpaceShipOne.
SpaceShipTwo made its first powered flight in April 2013. Richard Branson said it "couldn't have gone more smoothly".[6]
Enterprise was destroyed during a powered test flight on 31 October 2014, killing one pilot, Michael Alsbury, and seriously injuring another, Peter Siebold.[7] This was the first spacecraft-related accident in which part, but not all, of the crew survived. An investigation revealed the accident was caused by premature deployment of the "feathering" system, the ship's descent device; the NTSB also faulted the spacecraft's design for lacking fail-safe mechanisms that could have deterred or prevented early deployment.[8][9][10]
Initial projections by Virgin Galactic in 2008 called for test flights to begin in late 2009 and commercial service to start in 2011.[11][12] This schedule was not achieved, with captive carry and glide flight tests beginning in 2010, and the first test flight under rocket power in 2013.
In October 2009, Virgin Galactic CEO Will Whitehorn outlined the flight test program for SpaceShipTwo. The test program includes seven phases:
Vehicle ground testing
Captive carry under White Knight Two
Unpowered glide testing
Subsonic testing with only a brief firing of the rocket
Execute a detailed and lengthy appraisal process with the FAA/AST to demonstrate the system's robustness and eventually obtain a commercial launch license to begin commercial operations.[13]
On 22 March 2010, the SpaceShipTwo vehicle VSS Enterprise underwent a captive carry test flight, with the parent White Knight Two aircraft, VMS Eve, performing a short flight while carrying the Enterprise.[14] A second test flight was made on 16 May 2010,[15] reaching SS2's launch altitude (51,000 feet) and lasting nearly five hours, in order to facilitate "cold soak" testing of SS2's avionics and pressurization system. Thereafter, "a simulated spaceship descent/glide mission was made from [launch] altitude."[16] Between these two flights, the SpaceShipTwo airframe was modified by the addition of two interior fins, with one fin being added to the inside (rocket-side) of each of the craft's twin vertical stabilizers.[17]
On 15 July 2010, VSS Enterprise made its first crewed flight. The craft remained attached to VMS Eve as planned, and underwent a series of combined vehicle systems tests. The flight lasted a total of 6 hours and 21 minutes. A second, similar crewed flight of VSS Enterprise and VMS Eve was carried out on 30 September 2010, lasting approximately 5 hours. Among the objectives of these flights was the improvement of pilot proficiency, and the results of the flights were deemed to show that the systems were capable of supporting future glide missions.[15]
On 10 October 2010, VSS Enterprise made its first crewed gliding test flight. It was released from VMS Eve at 45,000ft (13,700 metres) and glided to a safe landing at the Mojave Air and Spaceport.[18][19][20] A second gliding test flight took place on 28 October 2010[21] and a third on 17 November 2010.[22]As of December 2010[update], Scaled reported that the flight test program was exceeding expectations.[23] The fourth test flight took place on 13 January 2011,[24] while the fifth and sixth glide flights occurred on 22 and 27 April 2011, respectively.[15] Following this, the feathered reentry configuration was tested in flight on 4 May 2011,[15] with weekly test flights continuing through the end of May.[15] On 9 June 2011, SS2 failed to separate from White Knight Two during its 11th planned glide flight due to a technical problem.[15] Testing resumed with five successful glide flights in June 2011.[15]
In July 2011, after 15 successful glide flights, flight testing of SS2 was halted for two months while planned revisions to the spaceplane were made.[25] Flight tests resumed in late September 2011, although the 16th glide flight– on 29 September– was marred by a brief loss of control aboard SS2, forcing the crew to utilise the feathered wing configuration to land safely.[26][27] This test was followed by another hiatus, during which some of the spacecraft's engine components were installed.[28] In June 2012, Scaled Composites received an FAA permit to conduct rocket-powered supersonic test flights.[29] SpaceShipTwo flight tests resumed in June 2012.[28][30]
In September 2012, Virgin Galactic announced that the unpowered subsonic glide flight test program was essentially complete. The company thereafter stated its intention to fit the hybrid rocket motor and control system to the vehicle, before resuming the glide flight test program with the rocket motor installed, in order to recharacterize the spacecraft's glide performance with slightly different weight distribution and aerodynamics.[31] In October 2012, Scaled Composites installed key components of the rocket motor, and SpaceShipTwo performed its first glide flight with the engine installed in December 2012.[32][33]
The spacecraft's first powered test flight took place on 29 April 2013, briefly driving SpaceShipTwo to a supersonic velocity.[34][35][36]Richard Branson said it "couldn't have gone more smoothly".[6]
On 5 September 2013, the second powered flight was made by the SpaceShipTwo. It broke the sound barrier, reached Mach 1.43, and climbed to 69,000 feet (21km) over the Mojave Desert under rocket power and descended using its tilt-wing "feathering" maneuver.[37] Space journalist Doug Messier reported that "the engine plume featured white smoke, not the black smoke seen on the April flight."[38]
On 10 January 2014, the third powered flight climbed higher than the previous flights, testing a new coating on the tail boom and other systems.[39]
On 31 October 2014, Enterprisebroke apart in flight during a powered test flight over California's Mojave Desert.[53][54][55] The flight began smoothly, with Enterprise being dropped from its WhiteKnightTwo carrier and igniting its engine at an altitude of 50,000 feet (15,000m).[53] About 60 to 90 seconds into the flight, an "anomaly" was reported that resulted in destruction of the ship.[53] The pilot in command, Peter Siebold, escaped from the craft and parachuted to safety; the copilot, Michael Alsbury, was killed in the crash.[53][10]
The National Transportation Safety Board conducted an independent investigation into the accident. In July 2015, the NTSB released a report that cited inadequate design safeguards, poor pilot training, lack of rigorous federal oversight and a potentially anxious co-pilot without recent flight experience as important factors in the crash.[10] The NTSB determined that the crash resulted from the co-pilot's premature deployment of the feathering mechanism, which is normally used to aid a safe descent. The NTSB also faulted the ship's designers for failing to protect against human error, noting that the spacecraft lacked fail-safe systems that would have prevented or deterred a premature deployment of the feathering mechanism.[10] The NTSB recommended that the FAA establish human factors guidance specific to commercial spaceflight operators and create a more rigorous application process for experimental spaceflight permits.[10]
Scaled Composites 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 develop experimental aircraft, the company now focuses on designing and developing concept craft and prototype fabrication processes for aircraft and other vehicles. It is known for unconventional designs, for its use of non-metal, composite materials, and for winning the Ansari X Prize with its experimental spacecraft SpaceShipOne.
SpaceShipOne is an experimental air-launched rocket-powered aircraft with sub-orbital spaceflight capability at speeds of up to 3,000 ft/s, using a hybrid rocket motor. The design features a unique "feathering" atmospheric reentry system where the rear half of the wing and the twin tail booms folds 70 degrees upward along a hinge running the length of the wing; this increases drag while retaining stability. SpaceShipOne completed the first crewed private spaceflight in 2004. That same year, it won the US$10 million Ansari X Prize and was immediately retired from active service. Its mother ship was named "White Knight". Both craft were developed and flown by Mojave Aerospace Ventures, which was a joint venture between Paul Allen and Scaled Composites, Burt Rutan's aviation company. Allen provided the funding of approximately US$25 million.
Peter Siebold is a member of the Scaled Composites astronaut team. He is their Director of Flight Operations, and was one of the test pilots for SpaceShipOne and SpaceShipTwo, the experimental spaceplanes developed by the company. On April 8, 2004, Siebold piloted the second powered test flight of SpaceShipOne, flight 13P, which reached a top speed of Mach 1.6 and an altitude of 32.0 kilometres (105,000 ft). On October 31, 2014, Siebold and Michael Alsbury were piloting the SpaceShipTwo VSS Enterprise on flight PF04, when the craft came apart in mid-air and then crashed, killing Alsbury and injuring Siebold.
The Mojave Air and Space Port at Rutan Field is in Mojave, California, United States, at an elevation of 2,801 feet (854 m). It is the first facility to be licensed in the United States for horizontal launches of reusable spacecraft, being certified as a spaceport by the Federal Aviation Administration on June 17, 2004. The facility covers 2,998 acres and has three runways.
Virgin Galactic is a 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 operates from New Mexico. The company is developing commercial spacecraft and aims to provide suborbital spaceflights to space tourists. Virgin Galactic's suborbital spacecraft are air launched from beneath a carrier airplane known as White Knight Two. Virgin Galactic‘s maiden spaceflight occurred in 2018 with its VSS Unity spaceship. Branson had originally hoped to see a maiden spaceflight by 2010, but the date was delayed for several years, primarily due to the October 2014 crash of VSS Enterprise.
The Scaled Composites Model 339 SpaceShipTwo (SS2) is an air-launched suborbital spaceplane type designed for space tourism. It is manufactured by The Spaceship Company, a California-based company owned by Virgin Galactic.
The Scaled Composites Model 348 White Knight Two (WK2) is a quadjet cargo aircraft that is used to lift the SpaceShipTwo spacecraft to release altitude. It was developed by Scaled Composites from 2007 to 2010 as the first stage of Tier 1b, a two-stage to suborbital-space crewed launch system. WK2 is based on the successful mothership to SpaceShipOne, White Knight, which itself is based on Proteus.
The Spaceship Company (TSC) is a British/American spacecraft manufacturing company that was founded by Burt Rutan and Richard Branson in mid-2005 and was jointly owned by Virgin Group (70%) and Scaled Composites (30%) until 2012 when Virgin Galactic became the sole owner. TSC was formed to own the technology created by Scaled for Virgin Galactic's Virgin SpaceShip program. This includes developments on the care-free reentry system and cantilevered-hybrid rocket motor, licensed from Paul Allen and Burt Rutan's Mojave Aerospace. The company is manufacturing Virgin Galactic's spacecraft and will sell spacecraft to other buyers. The suborbital launch system offered will include the SpaceShipTwo spacecraft and the White Knight Two carrier aircraft.
SpaceShip III is an upcoming class of spaceplanes by Virgin Galactic to follow SpaceShipTwo. It was first teased on the Virgin Galactic Twitter account on 25 February 2021 announcing the rollout of the first plane on 30 March 2021.
VSSUnity, previously referred to as VSS Voyager, is a SpaceShipTwo-class suborbital rocket-powered crewed spaceplane. It is the second SpaceShipTwo to be built and is part of the Virgin Galactic fleet. It first reached space as defined by the United States on 13December 2018, on the VP-03 mission.
RocketMotorTwo (RM2) is a family of hybrid rocket engines developed for the Scaled Composites SpaceShipTwo suborbital spaceplane.
David William Donald Mackay is the Chief Pilot of Virgin Galactic, a commercial astronaut and a former RAF test pilot. He is the first native-born Scot to visit space.
The VSS Enterprise crash occurred on October 31, 2014, when the VSS Enterprise, a SpaceShipTwo experimental spaceflight test vehicle operated by Virgin Galactic, suffered a catastrophic in-flight breakup during a test flight and crashed in the Mojave Desert near Cantil, California. Co-pilot Michael Alsbury was killed and pilot Peter Siebold was seriously injured.
Michael Tyner Alsbury was an American test pilot for Scaled Composites. He died on October 31, 2014, during test flight PF04 of the Virgin Galactic SpaceShipTwo VSS Enterprise.
VP-03 was a sub-orbital spaceflight of the SpaceShipTwo-class VSS Unity which took place on 13 December 2018, piloted by Mark P. Stucky and co-piloted by Frederick W. "CJ" Sturckow.
Mark P. "Forger" Stucky is an American test pilot and commercial astronaut. In these roles, he was an employee of Virgin Galactic, a private spaceflight company which is developing sub-orbital space tourism flights.
VSSImagine, is a SpaceShip III class suborbital rocket-powered crewed spaceplane. It is the first SpaceShip III to be built and will be used as part of the Virgin Galactic fleet. The spacecraft was rolled out 30 March 2021 and was planned to undergo ground and glide testing during summer 2021. Although as of spring 2022 it has not yet flown.
Virgin Galactic Unity 22 was a sub-orbital spaceflight of the SpaceShipTwo-class VSS Unity which launched on 11 July 2021. The crew consisted of pilots David Mackay and Michael Masucci as well as passengers Sirisha Bandla, Colin Bennett, Beth Moses, and Richard Branson.
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