Last Updated Nov 1, 2014 7:34 PM EDT
MOJAVE, Calif. -- The test pilot who survived Friday's crash of a Virgin Galactic prototype space tourism rocket in the California desert has been identified.
Kern County Sheriff Donny Youngblood says the pilot, 43-year-old Peter Siebold, is to undergo surgery. There were no other details on his condition Saturday.
Co-pilot Michael Alsbury, 39, was killed in the crash. Both men worked for Scaled Composites, the company developing the spaceship for Virgin Galactic.
On Saturday, Siebold was "alert and talking with his family and doctors," according to a statement released by Scaled Composites.
"We remain focused on supporting the families of the two pilots and all of our employees, as well as the agencies investigating the accident," the statement continued, asking privacy for the Alsbury and Siebold families.
A National Transportation Safety Board team arrived in Mojave, California, early Saturday to begin investigating.
Richard Branson, the founder of Virgin Galactic and a driving force in the push to commercialize space travel, vowed Saturday to find out what caused the fatal crash, to learn from the tragedy and to press ahead with plans to carry paying customers into space.
In grim remarks at the Mojave Air and Space Port, where SpaceShipTwo was under development, Branson gave no details of Friday's accident and deferred to the NTSB.
Branson said Virgin Galactic's engineers "understand the risks involved, and we're not going to push on blindly. To do so would be an insult to all those affected by this tragedy. We're going to learn from what went wrong, discover how we can improve safety and performance and then move forwards together."
The normally confident Branson was even more circumspect when asked if the dream of commercial spaceflight is still alive in the wake of the high-profile crash.
"It's fair to say that all 400 engineers who work here, and I think most people in the world, would love to see the dream living on," he said at the Mojave Air and Space Port in Mojave, California. "We owe it to our test pilots to find out exactly what went wrong, and once we've found out what went wrong, if we can overcome it, we'll make absolutely certain the dream lives on."
More than a dozen investigators in a range of specialties were forming teams to examine the crash site, collect data and interview witnesses, NTSB Acting Chairman Christopher A. Hart told a press conference at Mojave Air and Space Port, where the winged spacecraft was under development.
Hart said the investigation will have similarities to a typical NTSB probe as well as some differences.
"This will be the first time we have been in the lead of a space launch (accident) that involved persons onboard," said Hart, noting that the NTSB did participate in investigations of the Challenger and Columbia space shuttle disasters.
Hart said he did not immediately know the answers to such questions as whether the spaceship had flight recorders or the altitude of the accident, but noted that test flights are usually well-documented.
Friday's flight marked the 55th for SpaceShipTwo, which was intended to be the first of a fleet of craft. This was only the fourth flight to include a brief rocket firing. The rockets fire after the spacecraft is released from the underside of a larger carrying plane. During other flights, the craft either was not released from its mothership or functioned as a glider after release.
The problem happened about 50 minutes after takeoff and within minutes of the spaceship's release from its mothership, said Stuart Witt, CEO of the Mojave Air and Space Port.
SpaceShipTwo is based on aerospace design maverick Burt Rutan's award-winning SpaceShipOne prototype, which became the first privately financed manned rocket to reach space in 2004.
Friday's death was not the first associated with the program. Three people died during a blast at the Mojave Air and Space Port in 2007 during testing work on a rocket motor of SpaceShipTwo.