The investigation into what caused the Virgin Galactic test flight to crash could take as long as 12 months, lead investigator Chris Hart has said.
Mr Hart, who is acting head of the National Transportation Safety Board, also told reporters that his team would interview injured co-pilot Peter Siebold when he was ready.
Investigators in America say a safety device on the Virgin Galactic spacecraft had been deployed too early when it crashed on Friday.
But they say they can't yet work out why the device had gone wrong.
ITV News reporter Sejal Karia has the latest:
Faced with a five-mile debris trail and masses of technical data, the team investigating the crash of SpaceShipTwo have their work cut out.
The loss is a tragedy for this small tight-knit team that dreams of making the trip into space accessible to travellers not just astronauts.