Virgin Galactic's experimental VSS Enterprise SpaceShipTwo prototype broke apart in a test flight on Oct. 31, 2014. Early interest is focused on the ship's twin tail booms, which were deployed into their braking position too early.
Here's what investigators with the National Transportation Safety Board have announced as of Nov. 3, 2014:
Sequence of Events on Oct. 31, 2014
Takeoff: SpaceShipTwo is carried to 50,000 feet altitude (15.5 kilometers) by its White Knight Two carrier aircraft. The two vehicles took off from the Mojave Air and Spaceport at 9:20 a.m. PDT (12:20 p.m. EDT).
Separation: The craft separates normally from its carrier airplane and the hybrid rocket motor is fired as planned. SpaceShipTwo separates from WhiteKnightTwo at 10:10 a.m. PDT (1:10 p.m. EDT) to officially begin its fourth rocket-powered test flight. It is the 55th test flight of SpaceShipTwo. [Related: Virgin Galactic's Test Flight Milestones]
Anomaly: Nine seconds into the 70-second rocket burn, SpaceShipTwo's "feathering" system unexpectedly deployed, raising its twin tail booms up into a feathered position earlier than planned as the rocket continues to accelerate. The feathering system is designed to serve as a braking system during SpaceShipTwo's descent.
Breakup: Two seconds later, the SpaceShipTwo breaks apart, with debris crashing down to the Mojave Desert floor. According to the NTSB, the debris field covers an area 5 miles long.
SpaceShipTwo pilot Peter Siebold, director of flight operations for the spacecraft's builder Scaled Composites, managed to descend on his parachute and survived with minor injuries.
Co-pilot Michael Alsbury, a veteran Scaled test pilot, died in the accident.
Investigation: On Nov. 1, the NTSB begins its investigation in earnest, as a Go-Team arrives on site at the Mojave Air and Space Port. The investigation could last up to a year to pin down the cause of the accident.