VIDEO-1.8 BILLION DOLLARS-Virgin Galactic crash: Company defends safety record

Virgin Galactic insists safety has always been central to its operations, following the crash of its experimental spacecraft in the US on Friday.

The company said that principle "has guided every decision we have made over the past decade, and any suggestion to the contrary is categorically untrue".

SpaceShipTwo broke up in mid-air during a test flight in California's Mojave Desert, killing one of the two pilots.

Virgin Galactic hopes to sends tourists on suborbital flights.

An investigation into the crash could take about a year, the head of America's National Transportation Safety Board (NTSB) has said.

In a statement responding to criticism in the media about its approach to safety, Virgin Galactic said "everything we do is to pursue the vision of accessible and democratised space - and to do it safely".

It added: "Just like early air or sea travel, it is hard and complicated, but we believe that a thriving commercial space industry will have far reaching benefits for humanity, technology and research for generations to come.

"Now is not the time for speculation. Now is the time to focus on all those affected by this tragic accident and to work with the experts at the NTSB, to get to the bottom of what happened on that tragic day."

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Virgin Galactic founding astronaut Per Wimmer: "Space is difficult"

Virgin Galactic founder Sir Richard Branson has said he is "determined to find out what went wrong" and learn from the tragedy.

NTSB head Christopher Hart said on Sunday that the agency would be examining evidence at the scene for four to seven days.

He said the craft's debris was spread over an area measuring five miles (8km) from end to end.

He told a news conference the test flight had been "heavily documented" and his team would have to trawl through "extensive data", which was why the full investigation could take "about 12 months or so".

He said there were six cameras on the craft itself, with another three on its launcher, an aircraft called WhiteKnightTwo, although it was unclear whether SpaceShipTwo's cameras had been found.

Michael Alsbury

• Aged 39
• Married with two children
• 15 years of flying experience
• First flew in SpaceShipTwo in 2010
• Flew craft's first rocket-powered run in April 2013

Peter Siebold

• Aged 43
• Married with two children
• Received pilot's licence when just 16
• Started working for Scaled Composites in 1996
• Had spent 2,000 hours in 35 different fixed-wing aircraft

Will crash set back space tourism?

Virgin Galactic had hoped to launch commercially in 2015. It has already taken more than 700 flight bookings at $250,000 (£156,000) each, with Sir Richard pledging to travel on the first flight.

The spacecraft was flying its first test flight for nine months when it crashed near the town of Bakersfield.

Virgin Galactic said SpaceShipTwo had experienced "a serious anomaly" after it separated from WhiteKnightTwo.

The spacecraft was using a new type of rocket fuel never before used in flight, although officials said it had undergone extensive ground testing.

The co-pilot who died when SpaceShipTwo disintegrated shortly after take-off was 39-year-old Michael Alsbury.

Scaled Composites, the company employing both pilots, said surviving pilot Peter Siebold, 43, was "alert and talking with his family and doctors".