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.
Sir Richard Branson has paid tribute to Michael Alsbury - the test pilot who died in Friday's accident in the Mojave Desert in California.
A memorial fund has been set up to raise money for the pilot's wife and family.
He wished the other pilot who was injured in the incident a "speedy recovery".
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.