spacetoday.net: Foam impact cracks shuttle panel in test

Posted: Sat, Jun 7, 2003, 10:48 AM ET (1448 GMT)
STS-107 patch (NASA)

A shuttle leading edge wing panel suffered at least two cracks after being hit by a chunk of foam like the one that hit Columbia during launch in January, investigators revealed Friday. In a test Friday at the Southwest Research Institute in San Antonio, engineers fired a chunk of foam at a reinforced carbon-carbon (RCC) panel taken from the shuttle Discovery. While the impact of the 0.76-kg chunk, hitting the panel at about 845 kmph, appeared to do no obvious damage, later inspection turned up a crack 7.5 cm long on the panel and a second crack on the T-seal that separated the struck panel from an adjacent one; the panel and adjacent T-seals also shifted position from the force of the impact. The test is seen by many as strong evidence in support of the leading hypothesis for the Columbia accident, namely, that the foam impact during launch damaged the panel and/or T-seal, allowing hot gases into the wing during reentry. Investigators said that while they couldn't reach such a conclusion yet, they noted that had such damage been noted to a panel during a preflight inspection, the affected shuttle likely would not be allowed to fly. Investigators are considering performing an additional impact test similar to Friday's test later this month.