Last year, 31.10.2014,  SpaceShipTwo crashed on rocket powered test flight. It was estimated just after the accicent that the cause was human error, which has now been officially confirmed, (NTSB report 28.07.2015). Even good and trained pilot might make a mistake.

Co-pilot released the opening mechanism for the wings14 seconds too early, which caused the accident. Before this the flight went according to the plan. This accident has delayed the project, but now it can resume to the normal stage once the official report is released. The report does not put the blame on Virgin Galactic at any point. The second SpaceShipTwo will soon start the actual test flights. Virgin Galactic has kept us well-informed all the time of the accident investigation.

Virgin Galactic made an animation that explains why the accident occurred -> link.

News on BBC.COM -> link