Probe of crash may take 'a year'

Authorities who carried out their first full day of investigation into a US spacecraft crash that killed one pilot and seriously injured another have said probing the incident could take a year.

At a news conference late on Saturday, National Transportation Safety Board (NTSB) acting chairman Christopher Hart said debris from the SpaceShipTwo rocket crash was strewn over an area eight kilometres long, indicating a likely in-flight breakup, and would be part of an investigation lasting up to 12 months.

British tycoon and Virgin chief Richard Branson meanwhile insisted earlier in the day that he was undeterred and that his dream of commercial space travel was still alive. The doomed Virgin flight - the 35th by SpaceShipTwo, which is meant to carry tourists on short but expensive trips to space - marked the first time the spaceship had flown on a new kind of plastic-based rocket fuel mixture. A team of federal investigators launched a probe of the causes of Friday's accident, which dealt a devastating setback to commercial space tourism.

Although piecing together the facts and analysis surrounding the accident would be lengthy, Hart said the on-site investigation would last four to seven days.

Hart earlier told reporters that investigators were entering unknown territory since it was "the first time we have been in the lead of a space launch that involved persons on board".

However, he sounded a positive note late Saturday adding that as a test flight, the spaceship "was heavily documented in ways we don't usually see with normal accidents". That included six cameras on the vehicle and three on WhiteKnightTwo - the bigger aircraft that had carried the spaceship.

There was also extensive telemetry data and a long-range camera at nearby Edwards Air Force Base, among other sources of input, he said.

The crash was the second disaster to rock the private space industry in the space of a few days, after an Antares rocket carrying supplies to the International Space Station exploded after take-off in Virginia on Tuesday.

Early theories about the causes of the latest crash have focused on the fuel, amid reports the company was repeatedly warned of concerns about its safety.

A rubber-based fuel was previously used.