'Feathering system' involved in SpaceShipTwo crash

Mojave - Investigators say Virgin Galactic's experimental spaceship broke apart in flight over California's Mojave Desert after a device to slow the craft's descent prematurely deployed.

National Transportation Safety Board acting chair Christopher Hart said on Sunday that while no cause for Friday's crash has been determined, investigators found the "feathering" system was activated before the craft reached the appropriate speed.

The system requires a two-step process to deploy. The co-pilot unlocked the system but Hart said the second step occurred "without being commanded".

Hart said the SpaceShipTwo's fuel tanks and engines showed no signs of being compromised.

The co-pilot was killed. The pilot parachuted to the ground and is hospitalised.

This online footage shows the result of the crash which killed one crew member.