HOUSTON A data processing foul up by the U.S. Air Force prevented early flagging of a mystery object falling off Columbia in orbit an object that may be tied to why the space plane disintegrated en route to Earth.

During Columbias second day in Earth orbit, Air Force Space Command ground radar observed a large piece of structure floating free of the space plane. It remained in orbit for a little over two days before nose-diving into Earths atmosphere.

But no one in the Department of Defense or NASA knew about the discovery of the fairly large object until days after the loss of Columbia and its seven-person crew.

SPACE.com has learned that a data processing issue meant that analysts did not recognize the object for what it was a piece drifting away from Columbia. Meanwhile, the shuttle crew continued onward in its science-gathering mission, apparently unaware of the incident.

If NASA had known that the piece was cast off early in Columbias 16-day mission, a campaign to better characterize the object would have swung into high gear including use of ground and space-based assets of military and intelligence agencies.

Proper identification of the mystery object might have also spurred a judgement that Columbia was unfit for return to Earth. That knowledge, sources here say, would surely have kicked off an Apollo 13-style action plan to rescue the space planes crew.

The Columbia Accident Investigation Board (CAIB) is attempting to identify the mystery object.

The object in question could be a RCC panel that came loose, said James Hallock, a CAIB member and Chief of the Aviation Safety Division for the Department of Transportation at the Volpe Center in Cambridge, Massachusetts.

Hallock said at a CAIB press gathering March 18 that a shuttles rumble into orbit "is a wild ride."

"Im surprised a lot of things dont come loose," Hallock said. Once a shuttle settles into orbit, the environment is much milder, he added.

But given that mildness, would unfastened parts of the shuttles heat-thwarting hardware just fall off?

Hallock said that spinning around Earth, Columbia went through cycles of heat and cold that could contribute to some part of the space planes thermal protection system finally being set free.

CAIB chairman, Admiral Harold Gehman, added that just prior to the object being picked up by radar, Columbia performed a side-to-side maneuver. That motion could have set adrift the shuttle piece, he said.

Brigadier General Duane Deal, Commander of the Air Force 21st Space Wing told SPACE.com that tests are underway using 28 sample pieces of shuttle hardware to help determine what separated from Columbia and pinpoint the true nature of the object.

Radar signatures of the test specimens, Deal said, are to be contrasted to Air Force Space Command radar reflections of the mystery space object.

Deal said that the piece from Columbia was discovered after the accident versus while the shuttle was in orbit. "This [object] was not something being tracked while it was on orbit," he said, although several thousand radar observations were made to keep track of Columbias whereabouts while circling Earth.

Gehman told SPACE.com that the CAIB isnt specifically looking into NASA and contractor readiness in rescuing stranded astronauts. "Thats too narrow a hypothetical for me. I would look at that and look at ten other things too," he said.

On-orbit repair and inspection, even taking a lap around the International Space Station so its crew can survey a shuttle are worthy of consideration, Gehman said.