A large section of one of the shuttle Columbia's wings has been found near Fort Worth, a NASA official said today, but it's not yet clear whether it's the right wing or the left, the one that suffered a catastrophic structural problem during the ship's re-entry Saturday.

Michael Kostelnik, a senior NASA administrator in Washington, said the debris marked a "significant recovery," describing it as a "piece of the leading edge of the reinforced carbon carbon composite."

The leading edge of the left wing is the subject of an article in Aviation Week & Space Technology's Feb. 10 issue. The story quotes sources saying Air Force tracking cameras were able to detect major structural problems with the leading edge of Columbia's left wing one minute before the ship broke up. The appearance of the carbon carbon panels making up the left wing's leading edge was described as "jagged."

Any degradation at the protective leading edge panels, designed to reject the fierce heat of re-entry, likely would set up a fatal chain of events, leading to further structural damage and increasing aerodynamic drag.

Telemetry from the shuttle is consistent with this scenario, reflecting temperature-related sensor failures in the left wing's main landing gear wheel well, elevated temperatures along the left side of the fuselage above the wing and increasing aerodynamic drag that pulled the shuttle's nose to the left. It appears that drag ultimately exceeded the flight control system's ability to counteract, leading to the structural breakup of the vehicle.

"We do have a large piece of one of the wings," said Kostelnik. "It is not clear which wing this is, but obviously given the anomalies we have on the descent coming through the left wing, obviously this structure is very important."

As for the Air Force imagery, Kostelnik said "it is a long range optical photo taken by an Air Force laboratory and this optical photo, which is very poor resolution, you could draw a lot of (conclusions), but this photo was taken during the descent in between the start of these anomalies on the California coast and before the termination.

"So I can't really make a judgment on what the image actually shows. ... Clearly, this is the type of information the (independent investigation) board will make these judgments on and what it means. But it is during the time period when we're getting these anomalies on the ground. So whatever is happening, it's probably consistent with what that photo shows."

Kostelnik said he was not aware of any high-resolution military imagery of Columbia's left wing.

The Air Force told CBS News imagery from Kirtland Air Force Base in New Mexico was turned over to NASA for analysis. Kirtland operates powerful telescopes in Hawaii and the continental United States, including the Starfire Optical Range in New Mexico that would have been well-positioned to follow Columbia's fiery plunge through the atmosphere.

The Starfire facility includes several sophisticated telescopes, including a 1.5-meter instrument and a large 3.5-meter telescope, the largest in the world equipped with adaptive optics to counteract atmospheric shimmer. Whether one of these instruments produced the high-resolution imagery noted by Aviation Week is not yet known.

Otherwise, Kostelnik said debris recovery is continuing at full throttle as NASA's internal investigation makes the transition from leading the probe to serving the independent Columbia Accident Investigation Board in a support capacity.

As of this writing, no confirmed shuttle debris has been found west of Fort Worth. Debris recovered in California may or may not be shuttle related and is currently under analysis.

Kostelnik said nearly 1,500 men and women from a wide variety of agencies are participating in the search. About 220 NASA personnel are involved, some 800 National Guard troops in Texas and Louisiana, about 400 state troopers, 25 horse-mounted officers, dive teams, dog teams and 36 game wardens.