At a news conference late yesterday, 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.
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."
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.
A rubber-based fuel was previously used.
