Columbia sensor showed attempt to cut autopilot
Faulty data might be to blame, NASA engineers say
From Miles O'Brien
This image of Columbia in orbit was taken by the U.S. Air Force Maui Optical and Supercomputing Site on January 28, four days before the shuttle's breakup.
HOUSTON, Texas (CNN) -- A sensor aboard the space shuttle Columbia indicated an attempt to disengage its autopilot in the final two seconds before signals from the spacecraft were lost, but NASA engineers say faulty data might have caused the reading.
At the time, the orbiter was spinning wildly -- as fast as 20 degrees a second. Although the sensor could have indicated a last-ditch effort by the flight crew to right the doomed orbiter, at no time did telemetry from Columbia indicate the craft was under manual control.
Manually moving the steering mechanism -- or "stick" -- on a space shuttle automatically disengages the autopilot. But the sensor light, known as a "fault message," could have resulted from a technical failure of some kind, engineers said.
Columbia disintegrated during re-entry over Texas on February 1, just 16 minutes before a scheduled landing at Kennedy Space Center in Florida. All seven crew members on board were killed.
The sensor reading comes to light as NASA engineers continue their effort to decipher garbled data transmitted to the ground 32 seconds after the final radio transmission from Columbia. The data offer about five seconds of information, then a 25-second gap, and then the final two-second spurt.
NASA engineers are combing the data for any additional clues to the disaster. They are expected to release a revised timeline Monday of events on board Columbia during its final minutes.