Virgin Galactic crash: Slowing device ‘deployed early’.A safety device on the Virgin Galactic spacecraft that rammed on Friday deployed early during the fatal test flight, US investigators say .

Air safety chief Christopher Hart said the “feathering” device, designed to slow the craft on re-entry, activated without a command from the pilots.

But he said it was too early to say this caused the crash, in which one of the pilots died .

Previously , Virgin Galactic rebuffed criticism of its safety practices.

The company said any suggestion that safety had not been its top priority was “categorically untrue”.

Virgin Galactic had aimed to send tourists into space early next year, and has already taken more than 700 flight bookings at $250,000 (£156,000) each.

Christopher Hart said the inquiry was still in its early stages, and no cause had yet been determined Investigators have found most of the wreckage , which is strewn all around the Mojave desert

Mr Hart, from the US National Transportation Safety Board (NTSB), told reporters that the feathering device was supposed to be activated at Mach 1.4 (1,065mph; 1,715), but had been deployed at Mach 1 during the test flight.

He said one of the pilots had enabled the device, but the second stage of its deployment had happened “without being commanded”.

The feathering device lifts and rotates the tail to create drag, slowing the craft on its descent.

He said SpaceShipTwo’s fuel tanks and engines, which were highlighted in media reports over the weekend, showed no signs of being compromised.

NTSB investigators have now found nearly all of the parts of the rammed spacecraft as part of an inquiry they say could take many months to complete.

The pilots Peter Siebold, left, survived the incident but his co-pilot, Michael Alsbury, died

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 invested 2,000 hours in 35 different repaired -wing aircraft

Will crash set back space tourism?

SpaceShipTwo was flying its first test flight for nine months when it rammed near the town of Bakersfield.

Virgin Galactic said the craft experienced “a serious anomaly ” after it separated from launch vehicle WhiteKnightTwo.

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

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

The project has been subject to countless delays, and its commercial launch has been pushed back several times.

The Financial Times reported that the venture is facing financial difficulties – with $400m in funding from Abu Dhabi now dried up and Virgin Group covering the day-to-day expenses.

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 speaking with his family and medics “.