Updated 11:50 pm EDT with information from an NTSB briefing.

DURHAM, N.C. — The National Transportation Safety Board (NTSB) started its investigation Nov. 1 of the fatal crash of Virgin Galactic’s SpaceShipTwo suborbital spaceplane Oct. 31, as local officials released the identity of pilot killed in the accident.

The Kern County Coroner’s Office announced Nov. 1 that Michael Alsbury, a 39-year-old test pilot employed by Scaled Composites, was the person killed in the crash of the vehicle north of Mojave, California. Scaled Composites confirmed that identification in a press release issued late Nov. 1, which also stated that the pilot injured in the crash was the company’s director of flight operations, Peter Siebold.

Alsbury was the co-pilot of SpaceShipTwo on its first powered flight, in April 2013. According to public flight logs maintained by Scaled Composites, he most recently flew SpaceShipTwo as co-pilot on an unpowered test flight on Aug. 28, a “cold flow” test where nitrous oxide was vented through the engine but not ignited.

Siebold was the pilot or co-pilot of SpaceShipTwo on its previous four flights, including the Aug. 28 flight with Alsbury. Siebold was also a pilot on several test flights of SpaceShipOne, an earlier suborbital spaceplane developed by Scaled Composites that won the $10 million Ansari X Prize in 2004.

In the statement, Scaled Composites said that Siebold was “alert and talking with his family and doctors,” but provided no other details about his condition.

At a briefing late Nov. 1 at the Mojave Air and Space Port, NTSB acting Chairman Christopher Hart said the pattern of debris suggested to investigators that SpaceShipTwo broke apart in flight, corroborating photos and eyewitness accounts of the accident.

“The wreckage is located in a large area, oriented northeast to southwest, about five miles [eight kilometers] from end to end,” he said. “When the wreckage is dispersed like that, that indicates a likelihood of in-flight breakup.”

The left and right tail booms were found in the far northeast end of the debris field, he said, with the rocket engine at the opposite end of the field. Investigators also identified portions of the fuselage, cockpit, and two propellant tanks.

Hart said investigators had “extensive” data to work from, including six cameras mounted on SpaceShipTwo itself. “Because it was a test flight, it was heavily documented in ways that we don’t usually see in normal accidents,” he said.

The NTSB is likely to remain at the crash site for four to seven days, Hart said. The full investigation may take up to a year to complete. Hart noted that Virgin Galactic would be free to continue operations during the investigation, although Virgin Galactic officials said during a media tour of the company’s Mojave facilities last month that a second SpaceShipTwo under construction would not be ready for flight tests until next year.

In a first for an accident involving human spaceflight, NTSB will be the lead agency on the SpaceShipTwo investigation. “This will be the first time that we have been in the lead of a space launch that had persons on board,” Hart said of the investigation during a briefing earlier Nov. 1. The NTSB had previously been involved in the investigations of the Challenger and Columbia shuttle accidents, but in a supporting role.

Sir Richard Branson, founder of Virgin Galactic, arrived at the spaceport early Nov. 1. In a statement read to reporters, he said that he was determined to find out what caused the accident and to resume the company’s vehicle development efforts.

“We do understand the risks involved and we are not going to push on blindly: to do so would be an insult to all those affected by this tragedy,” he said in the statement. “We are going to learn from what went wrong, discover how we can improve safety and performance, and then move forwards together.”

Asked after the statement what the future of Virgin Galactic was, Branson paused for several seconds before answering. “We’d love to finish what we started some years ago,” he said. “I think pretty much all of our astronauts would love us to finish it so they can go to space.”

Twitter: @jeff_foust

Email: jfoust@spacenews.com

Jeff Foust has more than a decade of experience writing about space policy, entrepreneurial ventures and regulatory affairs. In 2001, he established spacetoday.net to aggregate and summarize the day's space-related news stories. In 2003, he started The...