Page "Space Shuttle Enterprise" Paragraph 19

In 2003 after the breakup of Columbia during re-entry, the Columbia Accident Investigation Board conducted tests at Southwest Research Institute, which used an air gun to shoot foam blocks of similar size, mass and speed to that which struck Columbia at a test structure which mechanically replicated the orbiter wing leading edge.

They removed a fiberglass panel from Enterprises wing to perform analysis of the material and attached it to the test structure, then shot a foam block at it.

While the panel was not broken as a result of the test, the impact was enough to permanently deform a seal.

Since the reinforced carbon-carbon ( RCC ) panel on Columbia had only 40 % of the strength of the test panel from Enterprise, this result suggested that the RCC leading edge would have been shattered.

Additional tests on the fiberglass were canceled in order not to risk damaging the test apparatus, and a panel from Discovery was tested to determine the effects of the foam on a similarly-aged RCC leading edge.

On July 7, 2003, a foam impact test created a hole 41 cm by 42. 5 cm ( 16. 1 inches by 16. 7 inches ) in the protective RCC panel.

The tests clearly demonstrated that a foam impact of the type Columbia sustained could seriously breach the protective RCC panels on the wing leading edge.