Cape Canaveral, Fla. ? NASA managers vowed on Tuesday to fully implement recommendations from the board probing the Columbia disaster as the shuttle fleet prepares to return to flight next year.

Because of the expected changes, agency officials conceded that resuming launches by NASA’s tentative target date of next March may be too optimistic.

“We understand that, one, we don’t have the Columbia Accident Investigation Board final report in front of us, so there will likely be adjustments there,” said Bill Readdy, NASA’s associate administrator for spaceflight. “Two, we also understand that perhaps March may be success-oriented. But we need to have something to get the team all marching in step on. … Is March ambitious? Probably.”

NASA Deputy Administrator Fred Gregory said the space agency was making “excellent” progress on five recommendations handed down so far by the investigation board. They include improving inspections of thermal panels on the leading edges of the shuttles’ wings, taking images of the ships in space to look for damage, developing techniques to inspect and repair the orbiters’ heat armor in orbit, and improving photo coverage of launches.

Several of the proposed changes would correct problems that may have contributed to Columbia’s breakup over central Texas while returning home Feb. 1.

A suspected hole in the left wing’s leading edge allowed blowtorch-like gases to enter and destroy the shuttle while re-entering Earth’s atmosphere. Investigators are convinced the hole was caused by foam insulation from the ship’s external fuel tank that broke free and struck the wing during launch.

Gregory pledged that NASA was committed to following all of the board’s eventual findings. The board’s final report is expected to be published in late August.