HUNTINGTON BEACH, Calif. - Veteran Boeing engineers say their company falsely led NASA to conclude that the space shuttle Columbia was safe to land because top managers assigned the task of assessing damage to employees who had never done that type of analysis for NASA.
"I think they wanted to paint a rosy picture, and they did," said a thermal systems engineer who did this kind of analysis for 10 years in California before Boeing shifted the work to its Houston offices last year.
Interviews with engineers at the Boeing plant here bolster outside experts' claims that the company grossly erred in its evaluation of wounds the shuttle might have suffered when debris slammed into its left wing during liftoff.
In one internal e-mail circulating among engineers here, an unnamed employee speculated that NASA is playing down the debris strike to fend off criticism that it might not have done enough to get the astronauts back safely.
"The NASA boys are 'back-pedaling' on the original theory of debris impact," the Boeing employee wrote. "I think they are trying to build a case to protect their asses for running with faulty thermal analysis."
Several engineers here began conducting their own analysis after the crash - using the same data and procedures that were used in Houston during the flight. Their results are not only different, but they also indicate that NASA had an emergency on its hands.
"We're redoing the analysis because we think it needs to be done differently," said another longtime shuttle engineer, an expert at calculating debris impact. "The re-analysis is finding things to be more harsh than the original."
It is not clear what caused the shuttle to disintegrate over the U.S. Southwest. An independent panel investigating the disaster has determined only that some type of breach allowed searing gases to enter the shuttle and melt its aluminum frame.
One possible cause of this is that the orbiter's thermal-protective tiles were damaged or missing, leaving the ship's thin aluminum skin vulnerable to a "burn-through."
When debris sloughed off the external fuel tank 81 seconds into launch and hit the wing, engineers began focusing on this possibility. With Columbia still in orbit, Boeing was asked to evaluate whether the damage could flare up into a burn-through during re-entry.
The engineers at Boeing's plant in Huntington Beach, Calif., say they had done these analyses for 20 years. But this year, they were not asked to.
The reason, they say: Boeing transferred shuttle jobs to Houston in a consolidation that cost the company scores of its most experienced shuttle engineers during the past two years - including some of those who invented the methodology for debris damage and thermal analysis.
Of 1,300 jobs in Boeing's shuttle program nationwide, 500 were transferred last year from California, officials said. Only 100 people made the move; scores of veteran engineers left the company or stayed behind, doing other work, said Boeing spokeswoman Kari Allen.
So as the clock was ticking toward Columbia's re-entry, Boeing managers relied on a Houston-based team of engineers who had never done this type of analysis in a real situation.
"This was their first flight," said the Boeing thermal systems engineer. "This was the first time they took over."
Allen said Friday she didn't know if that was true. "There's a whole lot of people who put that analysis together. Just because there were four names on the front doesn't mean there weren't many other people," she said.
The Houston team analyzed numerous scenarios, ultimately predicting a "safe return." Boeing executives have defended that analysis as the "best answers possible" from the "best technical minds." On Friday, Allen said the company "absolutely" stood by that statement, even as new e-mails released from NASA last week suggested some inside the agency voiced strong doubts.
The California engineers for Boeing - who have not only done this kind of number-crunching for years but helped invent the process - say the Boeing team in Houston grossly mis-analyzed the data.
"Basically, they just didn't interpret the numbers right," the thermal systems engineer said. "They never properly identified the risk."