Billionaire Virgin Galactic founder Richard Branson vowed on Saturday to find out what caused the crash of his prototype space tourism craft that killed one of two test pilots.

He said that while he remains committed to civilian space travel, "we are not going to push on blindly".

In grim remarks at the Mojave Air and Space Port, where the craft known as SpaceShipTwo was under development, Branson gave no details of Friday's accident and deferred to the US National Transportation Safety Board, whose team had just arrived to start an investigation.

"We are determined to find out what went wrong," he said, asserting that safety has always been the top priority of the program.

"Yesterday, we fell short," he said. "We'll now comprehensively assess the results of the crash and are determined to learn from this and move forward."

The pilot killed in the test flight was identified on Saturday as Michael Tyner Alsbury, 39, of nearby Tehachapi. The surviving pilot is Peter Siebold, 43, who parachuted to safety and was hospitalized.

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 said at Mojave Air and Space Port.

"This will be the first time we have been in the lead of a space launch (accident) that involved persons onboard," said Hart, adding that the NTSB took part in investigations of the Challenger and Columbia space shuttle disasters.

Virgin Galactic was set up to take wealthy tourists, six at a time, to the edge of space for a brief experience of weightlessness and a view of Earth.

The company - owned by Branson's Virgin Group and Aabar Investments of Abu Dhabi - plans to fly passengers to altitudes more than 100 kilometers above Earth. The company sells seats on each prospective journey for $250,000.

The company says "future astronauts", as it calls customers, include Stephen Hawking, Justin Bieber, Ashton Kutcher and Russell Brand. The company says it has received $90 million from 700 prospective passengers.

Show of support

On Saturday, Branson said none of that money has been spent and that anyone who wanted a refund could get it. However, he said, no one has asked, and instead someone signed up on the day of the accident in a show of support.

SpaceShipTwo was 18.3 meters long and featured two large windows for each of up to six passengers, one on the side and one overhead. Branson originally planned to begin passenger flights by 2007. Last month, he talked about traveling on the first flight with his son next spring.

Friday's test flight was the 55th by SpaceShipTwo. The accident was the second this week involving private space flight. On Tuesday, an unmanned commercial supply rocket bound for the International Space Station exploded moments after liftoff in Virginia.

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.

Three people died in a blast at the Mojave Air and Space Port in 2007 while testing a rocket motor for SpaceShipTwo.

(China Daily 11/03/2014 page12)