spacetoday.net: CAIB releases working scenario for Columbia accident

Posted: Wed, May 7, 2003, 6:11 PM ET (2211 GMT)
STS-107 patch (NASA)

The Columbia Accident Investigation Board (CAIB) published Tuesday a "working scenario" for the shuttle accident that blames the accident on a hole in the leading edge of the left wing, but stops just short of blaming the hole on falling foam during launch. According to the scenario, a hole on the leading edge of the wing, likely in the vicinity of reinforced carbon-carbon (RCC) panels 8 and 9, allowed hot plasma to enter the wing during reentry, creating damage to the wing and aerodynamic drag that eventually caused the orbiter to break up. The scenario also noted that foam from the external tank struck the same general area of the left wing 81 seconds after liftoff, but the CAIB has yet to conclude that the foam impact indeed caused the hole to form. The scenario also notes that debris floating away from the orbiter as seen on radar a day after launch is consistent with it being a T-seal or section of RCC panel, but noted that there was no "conclusive evidence" that the debris was either. The CAIB in continuing to investigate the accident with a series of tests and other studies to refine the details of the scenario, and the board leaves open the possibility of revising the scenario depending on the results from further work. A final report is still scheduled to be published this summer.