From a NASA press release:
Dittemore offered additional and refined information regarding the timeline of events that led to Columbia’s breakup on Saturday (all times CST):
ausing two out of four yaw steering jets in that area of the Shuttle to fire for 1.5 seconds to counteract the increased drag.
Although the investigative teams have a “high interest” in the left hand wheel well area of Columbia, Dittemore cautioned that a temperature increase there does not indicate that a structural problem occurred as a factor in the vehicle’s breakup. In fact, Dittemore said the data suggests that “something else” may have been happening at the time, not indicative of a structural breach.
Responding to inquiries regarding a piece of foam insulation which fell off Columbia’s external fuel tank about 80 seconds after launch that struck the left wing of the Shuttle, Dittemore said imagery analysis showed that the foam measured about 20 inches by 16 inches by 6 inches and weighed about 2.67 pounds. He reiterated that engineering analysis conducted during the flight concluded for NASA managers that although the foam might have caused some structural damage to the wing area, it would not have been sufficient to cause a catastrophic event.
“There is some other missing link contributing to this event,” Dittemore said. “We are extremely interested in seeing any debris that may have fallen upstream of the main impact area,” referring to any additional debris which might be recovered in an area to the west of Texas.