An investigation into the deadly crash of a Virgin Galactic spaceship has determined that a function to help the spacecraft descend into the atmosphere was deployed early.
The probe, which is being run by the National Transportation Safety Board, added that pilot error couldn't be ruled out yet, according to Reuters. The spacecraft crashed in California's Mojave Desert during a test flight on Friday, killing one pilot and injuring the other.
SpaceShipTwo's rotating tail boom, a key safety feature for re-entering the atmosphere, rotated early, Christopher Hart, acting chairman of the NTSB, said late this weekend. He added that it was too early to say whether this had caused the crash or not.
Virgin Galactic is the space tourism company of billionaire Richard Branson.
Hart said that investigators had determined the "feathering" system, which helps the craft descend into the atmosphere from space, should have been deployed when the vehicle was traveling around 1.4 times the speed of sound, during a news conference this weekend.
Instead, the system started rotating when the rocket-powered vehicle was traveling at Mach 1, using a technical term for the speed of sound at given altitude.
The feathering system, which folds the vehicle in half in order to create more atmospheric drag, was unlocked early by the co-pilot, according to video from the spaceship's cockpit. Two seconds later the tail began to fold.
"I'm not stating that this is the cause of the mishap. We have months and months of investigation to determine what the cause was," Hart said, according to Reuters.
Asked if the NTSB was considering the possibility of pilot error, Hart said: "We are not ruling anything out. We are 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 (of pilot error)."
SpaceShipTwo was released normally from its carrier aircraft, WhiteKnightTwo, at an altitude of about 45,000 feet. Soon after its hybrid rocket motor, which was flying for the first time with a new plastic propellant, ignited as planned, Hart said.
SpaceShipTwo's propellant tanks and engine were both recovered intact, indicating there was no explosion.
"The engine burn was normal up until the extension of the feathers," Hart said to reporters.
The two pilots involved were employees of Scaled Composites, a Northrop Grumman Co. subsidiary that designed and built the six-passenger, two-pilot craft for Virgin Galactic.
Branson and his son plan to fly on the first commercial flight, according to Reuters. Approximately 800 people already have paid or put down deposits for the ride, which costs $250,000.
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