Associated Press
July 7, 2003

A chunk of foam insulation fired at shuttle wing parts Monday blew open a gaping 16-inch hole, yielding what one member of the Columbia investigation team said was the "smoking gun" that proves what brought down the spaceship. The crowd of about 100 watching the test gasped and cried, "Wow!" when the foam hit -- the impact so violent that it popped a lens off one of the cameras recording the event.

THE FOAM STRUCK roughly the same spot where insulation that broke off Columbia's big external fuel tank during launch smashed into the shuttle's wing. Investigators had speculated that the damage led to the ship's destruction during re-entry over Texas in February, but Monday's test offers the strongest proof yet.

"We have found the smoking gun," Columbia Accident Investigation Board member Scott Hubbard said of the seventh and final foam-impact test by the board.

The 1.67-pound piece of fuel tank foam insulation shot out of a 35-foot nitrogen-pressurized gun and slammed into a carbon-reinforced panel removed from shuttle Atlantis.

The countdown boomed through loudspeakers, and the crack of the foam coming out at more than 500 mph reverberated in the field where the test was conducted.

Sixteen high-speed cameras captured the impact, and hundreds of sensors registered movements, stresses and other conditions. The impact was so strong that it damaged one of the gauges.

"There's a lot of collateral damage," Hubbard said.

Hubbard also said he believed the test showed that it would have been very difficult, if not impossible, to repair the foam damage during orbit.

NASA will continue gathering more information about the poorly understood pieces that line the vulnerable leading edges of shuttle wings, board member Scott Hubbard said.

One month ago, another carbon shuttle wing panel -- smaller and farther inboard -- was cracked by the impact, in addition to an adjoining seal. This time, the entire 11½-inch width of the foam chunk -- rather than just a corner during previous tests -- hit the wing, putting maximum stress on the suspect area.

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