HOUSTON - The NASA official who ran shuttle management meetings during the fatal Columbia mission said yesterday that she did not hear the continuing worries of engineers about debris that had struck the shuttle.
In her first public statement, Linda Ham, chairwoman of the mission management team, defended NASA and its staff with passion, and at times with tears. But her account also depicted a space agency in which internal communications broke down, whether because of a failure of process or of courage.
"I was never alerted to the concerns that were expressed by the engineers working the issue, neither the severity, the potential severity some of them felt about the damage, nor the fact that they wanted the on-orbit image," she told reporters at a briefing here.
She insisted that throughout the mission, managers "were basing our decisions on the best information that we had at the time." Ultimately, she said, "I don't believe anyone is at fault for this."
The National Aeronautics and Space Administration held the briefing on the same day that it released transcripts from the management team's meetings during Columbia's last flight. Those transcripts show that managers quickly embraced an optimistic analysis that suggested the foam insulation could not seriously damage the spacecraft and that they dismissed the issue.
In a crucial meeting Jan. 24, Ham cut off a NASA engineering manager, Don L. McCormack Jr., while he was presenting uncertainties and unknown risks from the piece of foam that struck the shuttle about 80 seconds into the launch. Ham repeatedly emphasized in the discussion after that one that the foam posed "no safety of flight" concern and "no issue for this mission."
"Nobody on this team believed that foam could hurt the orbiter, could hurt the RCC at all," said a person who has worked with the investigation, referring to the leading-edge panels of the wing, which are made of a brittle composite, reinforced carbon-carbon, also known as RCC. "They had one fundamentally flawed understanding: that foam couldn't harm RCC, and that colored everything else."
Because of the conclusion that the foam posed no safety threat to the shuttle, officials decided not to pursue requests to have outside agencies try to get pictures of the shuttle using spy satellites or powerful ground-based telescopes - which might have helped find the damage to the wing during the mission.
But Ham, despite being head of the mission management team, said she was never officially notified of these requests. Yesterday, Ham said she had "absolutely no reluctance to ask for outside assistance."
She said she had heard informally about a request for getting images of the shuttle from other agencies, but when she spent the better part of a day asking within NASA and at the chief shuttle contractor, United Space Alliance, trying to discover who made the request, she found no one. "It never came up again. Never. Not in a hallway, not in the mission management team," she said.
Previously released NASA documents show that other agency officials canceled at least two requests for outside photography during the mission.
In the briefing, Ham said top managers had to rely on the assessments of others. "I don't have the engineering expertise, nor do I have the tools, to do that kind of analysis," she said.
But to a NASA engineer who works closely with the mission management team, Ham's arguments sounded like an attempt to plead ignorance as a defense, which he called "unbelievable."
Ham became tearful as she described the effects of the Columbia disaster on her family and community. "We were all trying to do the right thing," she said. Ham, who is married to an astronaut, said members of the crew "are our friends. They're our neighbors. We run with them, work out in the gym with them."