CAPE CANAVERAL - A NASA timeline offers a conflicting glimpse inside shuttle Columbia's cockpit, where some data indicate the astronauts may have tried to take the ship off autopilot and fly manually in the final seconds of the doomed flight.
Other data, pieced together from the last two seconds of garbled information beamed down from the ship, suggest Columbia remained on computer control.
"We don't know for sure whether the commander or pilot tried to take control, but it certainly wouldn't be unheard of," said a Johnson Space Center manager, who asked not to be named. "We may never know."
The conflicting signals are part of the Feb. 27 timeline obtained by the Orlando Sentinel that painstakingly documents Columbia's plunge from orbit to its eventual destruction over Texas on Feb. 1.
Information from the last two seconds paints a picture of a heavily damaged ship, possibly missing some or all of its left wing and its left-side maneuvering rocket pod.
Instruments showed Columbia's nose veering left at 20 degrees per second, the maximum the shuttle's sensors could measure. The actual tumble rate may have been greater, meaning Columbia was in a slow downward spiral, taking no more than 18 seconds to complete a revolution.
The timeline also indicates a master alarm went off inside the cockpit at 8:59 a.m. It was a minute later when the data hint at the possibility that either Commander Rick Husband or pilot Willie McCool grabbed the stick, as if to fly Columbia manually. It is also possible the signals were in error.
Regardless, the timeline clearly shows the astronauts would not have been able to control the ship, which had suffered severe damage to some parts of the left side by that point. A leading theory is that the left wing was breached along its leading edge, allowing hot gases to get inside and destroy the wing from within.
"In the time period that we're talking about, the wing is disintegrating," said a source close to the Columbia Accident Investigation Board that is overseeing the search for the accident's cause.
While things were clearly happening on the left side, the rest of the shuttle was intact and many major systems were working normally. Investigators have pinpointed the start of Columbia's breakup at 9:00:21.