Washington ? The 1 1/2-pound chunk of foam insulation that tore a gaping hole in an old shuttle wing section struck with such force it would have broken even brand new panels, eliminating age as a major player in the Columbia disaster, investigators say.

“We exceeded the original design values of this material by 50 percent or more,” said Scott Hubbard, the Columbia Accident Investigation Board member who directed the foam-impact experiments.

Hubbard said Friday, four days after the dramatic test, that the aging of NASA’s space shuttle fleet and especially the thermal shielding on the wings “may well be a long-term maintenance issue.”

But he noted: “At least in this test with this particular foam block, we had more than enough force to break something even if it was fresh off the factory floor.”

The test Monday in San Antonio not only demonstrated the catastrophic effect of breakaway foam insulation but provided compelling evidence about the identities of a mysterious object that floated from Columbia in orbit and the many parts that peeled away from the shuttle as it flew toward its disintegration over Texas.

Those shedding pieces probably were fragments of the wing panel that had been damaged on takeoff two weeks earlier, Hubbard said.

“This single test, together with what else we know, is really allowing us to really connect the dots even further and draw some lines between various pieces of evidence,” he said.

The 16-inch hole created in the foam-strike test probably was larger than the gap in Columbia’s left wing where scorching gases entered during re-entry Feb. 1, said James Hallock, a physicist on the investigation board. An opening that big would have let in so much heat all at once that the shuttle would have broken apart much sooner than it did.

“Columbia would not have made it to the state of Texas,” he said.

Hallock said the hole in the leading edge of Columbia’s wing was probably 6 inches to 10 inches in size, based on thermal and other calculations.

The board’s chairman, retired Navy Adm. Harold Gehman Jr., said Monday’s test would enable him and the 12 other board members to use stronger language when describing the accident’s cause. They plan to release their final report by the end of August, a month later than planned.

Their investigation will have cost as much as $20 million by the time it’s completed, Gehman said.

The chunk of foam from Columbia’s external fuel tank broke off 81 seconds after liftoff in January and smashed into the vulnerable leading edge of the left wing at more than 500 mph.