快猫短视频

A CHUNK of fuel tank cladding fired at a replica space shuttle wing blew a whopping great hole in its leading edge last week. The foam easily breached the reinforced carbon composite (RCC) panels of the wing 鈥� a material NASA thought so strong it had barely tested it.

But the Columbia Accident Investigation Board says the impact test 鈥� performed as 快猫短视频 was going to press last week 鈥� did much more than pin the blame for the wing breach on the foam insulation. Carried out at the Southwest Research Institute in San Antonio, Texas, it managed to reproduce with uncanny accuracy at least four different aspects of the events thought to have taken place during Columbia鈥檚 final mission, as revealed by ground images, radar, and the doomed shuttle鈥檚 on-board sensors.

First, the test proved conclusively that a foam insulation block of the size and shape seen in the launch video could indeed cause enough damage to lead to the break-up of the craft when it re-entered the Earth鈥檚 atmosphere. The hole it made was so large (see Picture) that it is unlikely to have been repairable in orbit.

Secondly, the test forced several pieces of the broken leading edge material into the wing cavity, where they could easily have drifted loose once the shuttle arrived in orbit. One of these pieces was of a size and shape that precisely matched those of a 鈥渕ystery object鈥� that was seen floating away from the shuttle in radar images captured on its second day in space.

Further analysis of the wing replica, which used actual RCC panels from the surviving shuttles, revealed that in addition to the hole itself, the impact produced a series of deep cracks in the material, leaving some sections barely attached. These sections could account for the early pieces of debris that were seen falling to the ground as the shuttle passed over California, long before there were any signs of damage on-board.

Finally, the test damaged a seal that joined two panels in such a way that it could flap loose as if hinged at one end, which could have produced the hitherto unexplained pattern of scorching seen on an adjacent panel on debris recovered from Columbia.

But even as the impact test fingered the physical cause of the accident, the board made it clear that the problems they found with the space shuttle system itself 鈥� including some that played no part in this accident 鈥� are only part of the story.

Fully half of its final report, now expected in late August, will deal with the failures in management and communications, which allowed known problems to remain unaddressed and engineering concerns to be swept under the carpet. A cultural overhaul is in prospect for the space agency.

NASA鈥檚 key failure, says board chairman Hal Gehman, was one of attitude. It had begun to treat the shuttle as if it were an operational vehicle, rather than a developmental craft. Among other things, that meant that it was no longer bothering with as much testing and telemetry instrumentation, and it was not taking small anomalies as seriously as it should have.

As accident investigation board member Duane Deal put it at press conference last week: 鈥淭hey should treat each launch as the first launch, and each re-entry as the first re-entry.鈥�