(CNN) -- A day after the deadly failed test flight of Virgin Galactic's SpaceShipTwo, there were words of strength in the face of adversity. The pilots' bravery cannot be overstated, Virgin Group Founder Richard Branson said. The goal of commercial spaceflight remains unchanged, he added. But with one pilot's death, injuries to another and the loss of the aircraft, there are questions that must be answered along with the inspiring words. Virgin Galactic, Branson admitted, will not "push on blindly." To that end, a team of 13 to 15 investigators from the National Transportation Safety Board were on site in the Mojave Desert, where the debris from SpaceShipTwo was scattered over a five-mile area. The test aircraft went down about 20 miles northeast of Mojave.
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Pilot who survived identified as Peter Siebold, 43, Sheriff's Office says
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Authorities identify pilot who died as Michael Tyner Alsbury, 39
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Virgin Group founder Richard Branson vows to find out 'what went wrong'
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Both pilots worked for Virgin Galactic's partner, Scaled Composites
Siebold had worked for @placeholder since 1996, according to his biography on the company website, and had 17 years and more than 2,000 hours of flight experience.