New Orleans ? The space shuttle Columbia fought to stabilize itself after losing contact with controllers on the ground, NASA investigators said Saturday.

Two control jets fired after Mission Control lost contact with the shuttle, indicating that Columbia was plummeting out of control for as long as 15 to 20 seconds between the loss of contact with flight controllers and the shuttle’s breakup, NASA investigators said. The last voice communication from the shuttle’s seven astronauts came as Columbia streaked across New Mexico on Feb. 1.

It is not clear whether the new information will help in the search for the cause of the accident, but it means the seven astronauts may have had longer to understand what was happening. The new information comes from 32 seconds of “junk” telemetry data that were transmitted after voice contact was lost. The data were automatically discarded by NASA’s computers as “junk.”

NASA program officials had said efforts to recover the data were proving more difficult than anticipated.

Asked about the “junk” data, retired Adm. Harold W. Gehman Jr., chairman of a panel investigating the disaster, said “it’s too early” to assess its meaning. A spokesman for the panel said he was not aware that any conclusions had been reached about what the astronauts knew after losing contact with controllers.

The news Saturday came as NASA investigators also found a single tile 20 miles west of Fort Worth, possibly providing insight into the early stages of the spacecraft’s disintegration.

Most wreckage from the shuttle has been found in east Texas, but investigators have said pieces found farther west could provide evidence of what happened at the beginning of Columbia’s breakup.

“It tends to confirm the visual evidence that we have that the orbiter was shedding things before it got into the Fort Worth area,” Gehman said.