The crash investigation found that co-pilot Michael Alsbury prematurely unlocked the so-called feathering system that is intended to slow and stabilize the craft as it re-enters the atmosphere. Alsbury was killed, but pilot Peter Siebold, although seriously injured, parachuted to safety.
The "feathers" — a term derived from the design of a badminton shuttlecock — are tail structures that extend rearward from each wingtip. They are designed to swivel upward at an angle to create drag as the spacecraft reaches its apogee, preventing a buildup of speed and heat as the craft descends. The feathers then rotate back down to normal flying position as the craft enters the lower atmosphere.
A National Transportation Safety Board investigation found that Scaled Composites, a company that was developing SpaceShipTwo with Virgin Galactic and was responsible for its test program, should have had systems to compensate for human error. The NTSB chairman, Christopher Hart, said it wasn't a matter of shortcuts but of not considering a crew member would make the mistake that occurred.
Virgin Galactic subsequently assumed full responsibility to complete the test program.
The company stressed in a statement Thursday its commitment to testing from the level of individual parts on up to the complete craft.
"Our team's job is to plan out not just the obvious tests but also the strange and inventive ones, to conduct those tests, and to use the data from those tests to re-examine everything about our vehicle to ensure we can take the next step forward," it said.
The company did not project a timeline for actually carrying space tourists, noting that "our new vehicle will remain on the ground for a while after her unveiling, as we run her through full-vehicle tests of her electrical systems and all of her moving parts."
SpaceShipTwo is the successor to SpaceShipOne, the winged rocket plane that won the $10 million Ansari X Prize in 2004 by demonstrating a reusable spacecraft capable of carrying three people could make two flights within two weeks to an altitude of least 100 kilometers.
The prize announced in 1996 was intended to spur the development of private manned spaceflight in the same way the Orteig Prize offered in 1919 fostered trans-Atlantic aviation. Charles Lindbergh won that prize with his nonstop flight from New York to Paris in 1927.
Like SpaceShipOne, SpaceShipTwo is carried aloft beneath the wing of a mothership — a special jet aircraft that releases it at an altitude of about 45,000 feet. After gliding for a few moments, SpaceShipTwo's pilots ignite the rocket engine to send the craft hurtling toward space.
After reaching the top of its suborbital trajectory, the spacecraft begins falling back toward Earth and glides to a landing on a runway.
