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 Enterprise 's 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 by cm ( by in) 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.