GWEN IFILL: These past few days have been sobering ones for the small but growing industry of commercial spaceflight. A pair of accidents, one of which was deadly, are prompting questions about cost, safety, oversight, and even the wisdom of this shift in space travel.

NewsHour science correspondent Miles OBrien has the story.

MILES OBRIEN: Federal investigators are still combing through wreckage, as well as multiple data and video streams, in the wake of a deadly test flight high over Californias Mojave Desert.

Virgin Galactics SpaceShipTwo broke apart in flight on Friday, scattering debris over five miles. Investigators now believe the ships feathering system, which rotates the tail boom to create drag and slow descent, deployed early, and apparently without a command from the pilots.

The National Transportation Safety Boards chair, Christopher Hart, spoke last night.

CHRISTOPHER HART, Acting Chairman, National Transportation Safety Board: The spaceship was released normally, and after it was released, shortly after it was released, the rocket engine ignited. About nine seconds after the engine ignited, the telemetry data told us, showed us that the feather parameters changed from lock to unlock.

MILES OBRIEN: A two-man crew was on board. The co-pilot, Michael Alsbury, was killed. Pilot Peter Siebold, who parachuted to the ground, is hospitalized with serious injuries, but hes expected to recover.

It was the fourth powered flight for SpaceShipTwo, the first using a fuel derived from nylon. But the engine and the fuel and oxidizer tanks show no sign of an explosion. While there is no doubt that feathering during ascent would cause the vehicle to breakup, the NTSB will spend months trying to determine precisely what caused it to happen and what other factors might have contributed.

CHRISTOPHER HART: We will be looking at training issues. We will be looking at, was there pressure to continue testing? We will be looking at safety culture. We will be looking at the design, the procedure. We have got many, many issues to look into much more extensively before we can determine the cause.

MILES OBRIEN: Virgin Galactic says it has more than 700 customers on a waiting list, willing to part with as much as $250,000 for the short suborbital trip to the edge of space.

Follow this link:

Investigating crash, NTSB considers safety culture of commercial space flight Part 1