LOS ANGELES (AFP) – Investigators gave a precise timeline late Monday of the devastating Virgin Galactic spaceship crash, detailing exactly when a slowing mechanism was wrongly deployed, but said they could not determine who activated it.
The co-pilot of the SpaceshipTwo died in the crash Friday over California’s Mojave desert while the pilot survived the disaster, which has called into question Virgin chief Richard Branson’s dream of tourist flights to the edge of space.
Investigators said Sunday that a lock-unlock lever, used to activate a process in SpaceShipTwo’s tail section – typically to slow it for re-entry into the Earth’s atmosphere – had been moved by co-pilot Michael Alsbury.
But at a final on-scene press briefing late Monday, National Transportation Safety Board (NTSB) acting chairman Christopher Hart said he had been mistaken in identifying the co-pilot.
Video showed the person in the right seat move the lock-unlock lever, but Hart said investigators do not yet know which of the two crew – Alsbury, or pilot Pete Siebold, who survived – moved it.
Setting out the exact timeline, he said that the SpaceShipTwo was released from its mothership WhiteKnightTwo – which flew it up to some 45,000 feet – at 10:07 and 19 seconds.
Two seconds later the engines started. Eight seconds after that, at 10:07 and 29 seconds, the rocket reached .94 Mach, accelerating to 1.02 Mach by 10:07 and 31 seconds.
In that two-second period the lock-unlock lever was switched and the “feathering” mechanism started to deploy. At 10:07 and 34 seconds the data and video feeds from the rocket stopped, as it disintegrated over the desert.
It was unclear if the “feathering” – which acts like a badminton shuttlecock’s feathers, slowing the aircraft down during re-entry and pointing it in the right direction – started on its own or as a result of the lever being moved.
The lever, Hart said, was not supposed to be moved until reaching a speed of Mach 1.4. He reiterated that investigators would likely not announce a probable cause of the crash for up to 12 months.
Branson said earlier Monday that the deployment of the slowing mechanism may “well be” the cause of the catastrophe, while hitting out at what he called hurtful critics and “self-proclaimed experts.”
Speaking on NBC’s Today show Monday, Branson said he hadn’t seen the cockpit video showing the co-pilot triggering the lock-unlock switch.
“The NTSB, you know, are leading the investigation. And we go by exactly what they tell us,” he said.