Cape Canaveral, Fla. ? NASA’s redesigned space shuttle fuel tanks should no longer shed dangerous pieces of foam when launches resume next spring, officials said Thursday.

But if a shuttle wing is gouged by insulating foam or some other debris during liftoff, astronauts still will not be able to fix a hole the size of the one that brought down Columbia.

Speaking on the one-year anniversary of the Columbia accident investigation report, shuttle program manager Bill Parsons said he and others warned from day one that finding a way to repair the reinforced carbon edges of the wings in orbit would be a technical challenge.

“I mean, it’s just not something that you’re going to go out and come up with some kind of material that can deal with the return environment of up to 3,000 degrees and be able to just say, ‘OK, we can just do this repair and there you go,”‘ Parsons said.

Added NASA’s spaceflight chief, Bill Readdy: “The first priority is fix the tank, fix the tank, fix the tank and make sure that we don’t have a debris environment that would cause something like that.”

As for fixing the cultural problems that contributed to the Columbia disaster, NASA is making progress, said Thomas Krause, chairman of Behavioral Science Technology Inc., the California company hired to help transform the space agency.

There is strong evidence that employees are not as afraid to speak up at meetings; bosses encourage dissenting opinions and don’t interrupt as much, Krause said.

So far, NASA has complied with five of the 15 return-to-flight recommendations set forth by the Columbia Accident Investigation Board on Aug. 26, 2003.

The remaining 10 must be completed by December for NASA to launch Discovery to the international space station by mid-March to mid-April, the space agency’s goal.

“It’s been a hard year, but we’ve made significant progress in getting this vehicle ready for return to flight,” Parsons said.

Discovery’s external fuel tank should be delivered from Lockheed Martin Corp.’s assembly plant in New Orleans to Kennedy Space Center by early November. That is an essential step in meeting a spring 2005 launch date, Parsons said.

The tank will no longer have thick foam insulation on the spot where it tore off Columbia at liftoff. New heaters will be there instead, to prevent ice buildup when the tank is filled with super-cold fuel.