LOS ANGELES - A prematurely deployed slowing device could "well be" behind the Virgin Galactic spaceship crash, Virgin's boss Richard Branson said Monday while hitting out at "hurtful" critics and "self-proclaimed experts."
Investigators have pointed out 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 the co-pilot.
A short time later a so-called "feathering" process - in which the tail section rotates to increase drag on the spacecraft - was deployed, at which point the pioneering vessel began to disintegrate.
'Feathering' deployed prematurely
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.
Investigators from the National Transportation Safety Board (NTSB) have emphasised the cause of Friday's accident in the Mojave Desert has not been established.
Branson, speaking on NBC's Today show Monday, 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.
"But, you know, if the deployment did take place early, obviously, they're indicating that may well be the cause. But we need them to examine that further and let us know," he added.
But Branson also hit out against "hurtful" critics and "self-proclaimed experts" after a rocket scientist said the company had ignored safety warnings ahead of the deadly crash of one of its spacecraft.
"I've never seen such irresponsible innuendo and damaging innuendo," the British business tycoon told Britain's Sky News television, referring to critical press reports in Britain.
'We must push on'
Carolynne Campbell, an expert with the Netherlands-based International Association for the Advancement of Space Safety, told AFP on Sunday that she and other experts "were concerned about what was going on at Virgin Galactic." She said multiple warnings about the spacecraft's motor and the fuel used to power it had been issued to Virgin since 2007, when three engineers died testing a rocket on the ground.
"I warned them... that the rocket motor was potentially dangerous," she said.
Campbell's warnings related to nitrous oxide, reportedly used as a fuel component in the doomed craft along with a new substance derived from nylon plastic grains.
Branson wants to ferry wealthy customers to the edge of space, charging US$250,000 (S$322,385) per ticket, and the crash is expected to delay the programme.