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.
The SpaceShipTwo rocket disintegrated in mid-flight after a key lever was moved earlier than it should have been, the acting head of the US National Transportation Safety Board (NTSB) has said.
Chris Hart explained that the ship featured two sections at its back known as "feathers", which are designed to rotate to create more drag as the ship re-enters the earth's atmosphere.
To allow 'feathering' to take place, two handles have to be moved - one which locks and unlocks the feathers, and the other which moves them into position.
However, Mr Hart said data recovered from SpaceShipTwo showed that the 'lock/unlock' handle was moved but the second lever, known as the 'feathering handle', was not.
Mr Hart also said the 'unlock' handle was released at a speed of Mach 1.0, below the required speed of Mach 1.4
However, he emphasised strongly that investigators were still far from establishing the cause of the ship's disintegration.
"We are a long way from finding cause, we still have months and months of investigations to do, a lot that we don't know. We have extensive data sources to go through," he said.
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.