Virgin Galactic space plane's re-entry system activated early, say investigators
SpaceShipTwo (SS2) was equipped with a “feathering system” to reduce
its speed and stabilise its descent on return to Earth, but
investigators found that the mechanism was activated before the space
plane had reached the right speed during Friday’s test flight. When the feathering system is deployed, the space plane’s twin tail
booms rotate forwards and upwards, dramatically increasing aerodynamic
drag and making the craft fall like a shuttlecock. A combination
of photos show Virgin Galactic’s SpaceShipTwo as it detached from the
jet aeroplane that carried it aloft and then broke apart.Photograph: Kenneth Brown/ReutersChristopher Hart, the acting chairman of the US National
Transportation Safety Board, told a press conference on Sunday night
that the co-pilot, Michael Alsbury, had unlocked the feathering system,
but that the second stage of the process, which moves the wings into the
feathering position, happened “without being commanded”. “After it was unlocked, the feathers moved into the deployed position and two seconds later we saw disintegration,” he said. “Normal launch procedures are that after the release, the ignition of
the rocket and acceleration, that the feathering devices are not to be
moved – the lock/unlock lever is not to be moved into the unlock
position – until the acceleration up to Mach 1.4,” he added. “Shortly
after the feathering occurred, the telemetry data terminated and the
video data terminated.” But Hart stresssed that the premature deployment of the space plane’s
feathering system was “a statement of fact and not a statement of
cause”. Investigators could take many more months to reach firm
conclusions over the cause of the accident. Asked whether investigators were “edging” towards the possibility of
pilot error, he added: “We’re not edging towards anything. We’re not
ruling anything out. We’re looking at all of these issues to determine
what was the root cause of this mishap. We are looking at a number of
possibilities including that possibility (pilot error).” “We are a long way from finding cause. We still have months and months of investigation to do,” Hart said. Fifteen federal US investigators have been combing the site of the
fatal crash in California’s Mojave desert. On Sunday, the space plane’s
fuel tanks and engine were found intact, contradicting earlier claims
that SpaceShipTwo had exploded. The space plane on which the Virgin boss Sir Richard Branson has
pinned his hopes of sending commercial passengers to the edge of space –
at a cost of $250,000 (£156,000) each – broke up during a test flight
at about 45,000ft on Friday. The pilot, Peter Siebold 43, managed to
parachute to the ground and was described as alert though with serious
injuries; the co-pilot, Michael Alsbury, 39, was killed. Pilot Michael Alsbury, who was killed in the Virgin SpaceShipTwo crash in the Mojave desert in California on Friday.Photograph: David McNew/Getty ImagesVirgin Galactic has denied reports that it ignored safety warnings
ahead of Friday’s test flight crash. “At Virgin Galactic, we are
dedicated to opening the space frontier, while keeping safety as our
‘North Star’. This has guided every decision we have made over the past
decade, and any suggestion to the contrary is categorically untrue.” In an interview with Sky News, Branson said: “We’ve spent many, many
years building a spacecraft, a mothership, a space port, that I think
can do the job and do the job safely. We will not start taking people
until we’ve finished a whole massive series of test flights and until
myself and my family have gone up, and until we feel that we can safely
say to people ‘we’re ready to go’.” “We need to be absolutely certain our spaceship has been thoroughly
tested – and that it will be – and once it’s thoroughly tested and we
can go to space, we will go to space. We must push on. There are
incredible things that can happen through mankind being able to explore
space properly,” he added.
Virgin Galactic space plane's re-entry system activated early, say investigators
Safety board chairman says premature deployment of feathering system ‘a statement of fact and not a statement of cause’
US investigators say a function designed to help Virgin Galactic’s crashed space plane descend was deployed early.
Virgin Galactic’s space plane broke apart in mid-air seconds after
its re-entry system deployed prematurely in an accident on Friday that
killed one of its pilots and left another seriously injured, US crash
investigators have said. SpaceShipTwo (SS2) was equipped with a “feathering system” to reduce
its speed and stabilise its descent on return to Earth, but
investigators found that the mechanism was activated before the space
plane had reached the right speed during Friday’s test flight. When the feathering system is deployed, the space plane’s twin tail
booms rotate forwards and upwards, dramatically increasing aerodynamic
drag and making the craft fall like a shuttlecock.
A combination
of photos show Virgin Galactic’s SpaceShipTwo as it detached from the
jet aeroplane that carried it aloft and then broke apart.Photograph: Kenneth Brown/ReutersChristopher Hart, the acting chairman of the US National
Transportation Safety Board, told a press conference on Sunday night
that the co-pilot, Michael Alsbury, had unlocked the feathering system,
but that the second stage of the process, which moves the wings into the
feathering position, happened “without being commanded”. “After it was unlocked, the feathers moved into the deployed position and two seconds later we saw disintegration,” he said. “Normal launch procedures are that after the release, the ignition of
the rocket and acceleration, that the feathering devices are not to be
moved – the lock/unlock lever is not to be moved into the unlock
position – until the acceleration up to Mach 1.4,” he added. “Shortly
after the feathering occurred, the telemetry data terminated and the
video data terminated.” But Hart stresssed that the premature deployment of the space plane’s
feathering system was “a statement of fact and not a statement of
cause”. Investigators could take many more months to reach firm
conclusions over the cause of the accident. Asked whether investigators were “edging” towards the possibility of
pilot error, he added: “We’re not edging towards anything. We’re not
ruling anything out. We’re looking at all of these issues to determine
what was the root cause of this mishap. We are looking at a number of
possibilities including that possibility (pilot error).” “We are a long way from finding cause. We still have months and months of investigation to do,” Hart said. Fifteen federal US investigators have been combing the site of the
fatal crash in California’s Mojave desert. On Sunday, the space plane’s
fuel tanks and engine were found intact, contradicting earlier claims
that SpaceShipTwo had exploded. The space plane on which the Virgin boss Sir Richard Branson has
pinned his hopes of sending commercial passengers to the edge of space –
at a cost of $250,000 (£156,000) each – broke up during a test flight
at about 45,000ft on Friday. The pilot, Peter Siebold 43, managed to
parachute to the ground and was described as alert though with serious
injuries; the co-pilot, Michael Alsbury, 39, was killed.
Pilot Michael Alsbury, who was killed in the Virgin SpaceShipTwo crash in the Mojave desert in California on Friday.Photograph: David McNew/Getty ImagesVirgin Galactic has denied reports that it ignored safety warnings
ahead of Friday’s test flight crash. “At Virgin Galactic, we are
dedicated to opening the space frontier, while keeping safety as our
‘North Star’. This has guided every decision we have made over the past
decade, and any suggestion to the contrary is categorically untrue.” In an interview with Sky News, Branson said: “We’ve spent many, many
years building a spacecraft, a mothership, a space port, that I think
can do the job and do the job safely. We will not start taking people
until we’ve finished a whole massive series of test flights and until
myself and my family have gone up, and until we feel that we can safely
say to people ‘we’re ready to go’.” “We need to be absolutely certain our spaceship has been thoroughly
tested – and that it will be – and once it’s thoroughly tested and we
can go to space, we will go to space. We must push on. There are
incredible things that can happen through mankind being able to explore
space properly,” he added.
Friday’s launch was the fourth powered flight for SS2 and was
intended to test how the space plane fared on re-entry at supersonic
speeds rather than to monitor the new fuel or the performance of the
rocket on the way up. The flight occurred in the context of very ambitious targets set by
Virgin Galactic, which had been aiming to premier the first commercial
flights as early as next spring. The desire to make the venture
commercially viable carried with it huge engineering challenges. Prime among those was to design a spacecraft capable of carrying six
fee-paying passengers and two pilots as high as the edge of Earth’s
atmosphere, the notional marker called the Karman Line, some 100km above
sea level. Not only that, the enormous ticket price paid by the citizen
astronauts on board had to be rewarded with a view back to Earth and
its hazy blue atmosphere, and the experience of weightlessness. SS2’s predecessor, SpaceShipOne, travelled to the edge of space twice
in two weeks, returning to Earth safely on both occasions, 10 years
ago. But the smaller craft could only carry two astronauts – not
sufficient to make it commercially viable. Will Whitehorn, former president of Virgin Galactic, rejected any
suggestion that the project had been rushed. “This is nonsense. The
project started in 2004 … this is the longest test flight in the
commercial sector in history.” • This article, including the headline, which highlighted the
questions over the new fuel mix used on SS2, were updated after the NTSB
announced that the fuel tanks were discovered intact.
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