VIDEO: NTSB news conference on start of SpaceShipTwo investigation

Four-and-a-half years after an initial sub-orbital test flight, Richard Branson’s Virgin Galactic is finally ready to begin commercial operations with the launch Thursday of a six-man crew, including three Italian researchers, on an up-and-down flight to the edge of space aboard the company’s winged spaceplane.

Investigators have plenty of evidence to sift through as they look into the cause of the fatal crash of a Virgin Galactic rocket plane, but the acting chair of the National Transportation Safety Board said the inquiry may take up to a year to complete.

Virgin Galactic launched its suborbital spaceplane “Unity” on its first crewed flight in two years Thursday, carrying two pilots and four company astronauts to the edge of space in a final test flight before paying customers begin suborbital jaunts in June.