LOS ANGELES — An experimental rocket ship broke apart in flight over California’s Mojave Desert after a device to slow the space plane’s descent deployed too soon, federal investigators said.
The cause of Friday’s crash of Virgin Galactic’s SpaceShipTwo has not been determined, but investigators found the “feathering” system — which rotates the twin tail “feathers” to create drag — was activated before the craft reached the appropriate speed, National Transportation Safety Board Acting Chairman Christopher Hart said.
The system requires a two-step process to deploy. The co-pilot unlocked the system, but Hart said the second step occurred “without being commanded.”
“What we know is that after it was unlocked, the feathers moved into the deploy position, and two seconds later, we saw disintegration,” Hart said.
The finding moves away from initial speculation that an explosion brought down the craft.
The investigation is months from being completed, and officials are looking at factors that include pilot error, mechanical failure, design problems and whether pressure existed to continue testing, Hart said.
“We are not edging toward anything. We’re not ruling anything out,” he said. “We are looking at all these issues to determine the root cause of this accident.”
The co-pilot, Michael Alsbury, 39, was killed in the crash. Pilot Peter Siebold, 43, parachuted to the ground and is hospitalized with injuries.
Investigators have not interviewed Siebold because of his condition, Hart said.
Virgin Galactic — owned by billionaire Richard Branson’s Virgin Group and Aabar Investments PJS of Abu Dhabi — plans to fly up to six passengers at a time more than 62 miles above Earth, where they can experience weightlessness. The company sells seats on each prospective journey for $250,000.
Branson told Sky News on Monday that the company will move forward despite the crash. He said there would be a “whole massive series of test flights” before any trips are made.
He still plans to be on the maiden voyage, with his family.
“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,” Branson said.
“We must push on. There are incredible things that can happen through mankind being able to explore space properly,” he said.
SpaceShipTwo tore apart Friday about 11 seconds after it detached from the underside of its jet-powered mother ship and fired its rocket engine for the test flight. Initial speculation was that an explosion occurred, but the fuel and oxidizer tanks and rocket engine showed no sign of being burned or breached, the NTSB said.
The feathering system is a feature unique to the craft to help it slow as it re-enters the atmosphere. After being unlocked, a lever must be pulled to rotate the twin feathers toward a nearly vertical position to act as a brake. After decelerating, the pilots reconfigure the feathers to their normal position so the craft can glide to Earth.
A review of footage from a camera mounted to the ceiling of the spaceship’s cockpit showed the co-pilot moving the feathering lever to the unlock position, Hart said.
The feathers activated at Mach 1.0, the speed of sound, or 760 mph, Hart said. They should not have deployed until the craft had reached a speed of at least Mach 1.4, or more than 1,000 mph.
Virgin Galactic CEO George Whitesides issued a statement Sunday to tamp down on conjecture about the cause of the crash.
“Now is the time to focus on all those affected by this tragic accident and to work with the experts at the NTSB, to get to the bottom of what happened on that tragic day, and to learn from it so that we can move forward safely with this important mission,” he said.
SpaceShipTwo has been under development for years and has seen setbacks. In 2007, an explosion killed three people and critically injured three others during a ground test in the development of a rocket engine.