Investigators: Virgin Galactic Crash Caused By Brake System Error

A Virgin Galactic test flight crash that killed a co-pilot in October was caused by a structural failure when one of the crew triggered the spacecraft’s brake system early, The National Transportation Safety Board said on Tuesday.

The private space company hoping to one day fund commercial spaceflight was testing its SpaceShipTwo craft over the Mojave Desert 10 months ago when it crashed, killing one pilot and severely injuring the other.

The crash occurred because one of the pilot’s unlocked the braking system at Mach 0.92 instead of Mach 1.4, according to the Verge. Because there was no failsafe in place, the brakes were applied early, and the craft broke up and crashed in the desert below.

More technical details, per the Verge:

The vehicle’s two tail wings are supposed to move when the spacecraft hits a certain speed, a maneuver known as “feathering.” This repositioning helps to increase drag in order to slow the vehicle down for reentry. The NTSB found that the co-pilot Michael Alsbury — who died in the crash — unlocked the feathering system early, doing so at Mach 0.92 instead of the intended speed of Mach 1.4. This triggered the feathering maneuver to occur prematurely, which ultimately caused the vehicle’s “catastrophic structural failure,” said Lorenda Ward, the NTSB investigator in charge of the SpaceShipTwo crash.

“Many of the safety issues that we will hear about today arose not from the novelty of a space launch test flight, but from human factors that were already known elsewhere in transportation,” NTSB chairman Christopher Hart said, according to the Associated Press.

Virgin Galactic is building another craft for testing, and hopes to eventually be able to carry six passengers more than 62 miles above the earth’s surface.