The space station can still be completed in time given, an administrator said.
The next space shuttle launch will probably be delayed at least until March to give NASA more time to make engineering changes aimed at reducing the craft's ongoing foam-shedding problem, agency officials said Thursday.
The delay will also give officials a chance to consider an independent report, commissioned by the agency and released Wednesday, which analyzed NASA's efforts to correct organizational failings that contributed to the loss of shuttle Columbia in 2003.
That 220-page assessment, by a 26-person committee of experts, is mostly positive. But it includes a highly critical "minority report" signed by seven committee members who claim the agency continues to ignore certain risks to get the shuttle program aloft again.
"It appears to us that lessons that should have been learned have not been," the minority asserted, noting a "cycle of smugness substituting for knowledge."
Speaking to reporters Wednesday at NASA headquarters, NASA administrator Michael Griffin said he had not yet fully studied the report but made clear he wasn't afraid to consider the criticisms. Toward the end of the committee's deliberations, he said, its leaders told him that some members had dissenting opinions and asked whether those should be included in the report or distributed separately. Griffin said to include them, he recalled.
"We welcome the advice ... in the spirit of openness and honest acceptance," he said Wednesday.
Griffin denied charges leveled by some critics that the agency is being overly driven by a face-saving desire to complete most of the international space station before the aging shuttle fleet is mothballed.
There's been a "change of thinking," Griffin said. "We are not trying to get a specific number of flights out of the shuttle system. We are working toward an expeditious but orderly retirement of the shuttle," he acknowledged. But "we believe that, absent major problems, we can essentially complete the space station in the time we have available."
Griffin and William Gerstenmaier, the agency's new director of manned space operations, said engineers are still analyzing data from the recent flight of Discovery, whose successful mission was flawed by the loss of one large piece of foam and several smaller ones. A similar incident precipitated Columbia's disintegration upon re-entry.