spacetoday.net: Investigators consider wind shear, weakened wing in Columbia probe

Posted: Thu, Mar 13, 2003, 9:02 AM ET (1402 GMT)
STS-107 patch (NASA)

Members of the Columbia Accident Investigation Board (CAIB) said this week that they are considering a number of factors that could have led to the loss of the shuttle, including a strong wind shear the shuttle encountered during launch. Investigators said that Columbia flew through an unusually strong wind shear about one minute after launch, just seconds after passing "max Q", the moment of maximum dynamic pressure on the orbiter. That shear, combined with compensating thrust from the left solid rocket booster, could have placed additional stress on the shuttle's left wing, making it more susceptible to damage from falling foam. CAIB members also said they were investigating pre-launch repairs to the bipod area of the external tank, from where the foam that struck the orbiter fell. The CAIB said it is making progress on the investigation, but doesn't believe it is moving "rapidly", noting that the root cause remains elusive. Even pilot error has not been ruled out, SPACE.com reported, although the CAIB believes it to be unlikely.