This excerpt from a NASA press release contains an interesting initial reconstruction of the last minutes before Columbia broke up:
Dittemore reconstructed the final minutes of Columbia’s flight before communications was lost. He reiterated the failure of four temperature sensors associated with the shuttle’s left hand elevons at 7:53 a.m. CST Saturday amidst a 20-30 degree rise in left hand bondline and strut temperatures over a five-minute period near the left wheel well of the orbiter. Columbia was flying over California at the time at an altitude of about 220,000 feet traveling 21 times the speed of sound.
One minute later, over the region of eastern California and western Nevada, Columbia’s mid-fuselage bondline temperatures above the left wing experienced an unusual temperature increase. It rose 60 degrees over a five-minute period. No such temperature increase was noted on the right side of Columbia or in the Shuttle’s cargo bay. Columbia was about 212,000 feet above the Earth, flying at Mach 20.
At 7:58 a.m. over New Mexico, telemetry showed a larger than normal drag on the left side of the shuttle, and an indication of an increase in pressure in the left main landing gear tires. Dittemore said the data suggests the tires remained intact. Columbia’s altitude was 209,000 feet.
At 7:59 a.m. over west Texas, the data showed Columbia continuing to react to an increased drag on its left side, trying to correct the movement by rolling back to the right. Dittemore said the response of the orbiter was well within its capability to handle such maneuvers.
At that time, seconds before 8 a.m. CST, all communications was lost with Columbia as it flew at an altitude of 207,000 feet, 18 times the speed of sound.
Dittemore indicated that ground computers may contain an additional 32 seconds of data which could provide additional information in the analysis of Columbia’s breakup.
He added that the loss of some foam insulation from Columbia’s external fuel tank, which struck the shuttle’s left wing about 80 seconds after launch was “inconsequential” based on video imagery review conducted by engineering specialists. However, he said nothing has been ruled out as a possible cause for the accident.
Most interesting is the initial finding that the foam insulation was inconsequential, especially as so many armchair analysts are faulting NASA for failing to inspect the point of impact on the orbiter while they were in space. Also interesting is that they already have so much information on the sequence of events.