NASA Complacency, Missteps Cited

NASA had come to accept foam debris falling off the external tank and striking the space shuttle during launches, even though the agency had originally considered such impacts a safety risk, Columbia accident investigators said Tuesday.

The complacency about the foam debris incidents has striking similarities to the space agency’s behavior before the Challenger accident in 1986, when it knew there were serious defects with the solid rocket motors but failed to address them.

Sally Ride, the first American woman in space and a member of the Columbia Accident Investigation Board, said Tuesday at a news conference in Houston that she hears an “echo” of the management errors that led to the Challenger accident. Ride also served on the Challenger investigating commission.

In the Challenger era, NASA accepted known defects in the solid rocket motors because they had not caused problems.

“You survived the first time, so now it becomes normal,” said Ride, a faculty member at UC San Diego. “I think we’re trying to understand whether that same thinking crept in with the foam off the tank.”

The board has not yet reached a verdict on what caused Columbia’s destruction on Feb. 1, but it continues to zero in on the foam debris gravely damaging the leading edge of the orbiter’s left wing.

NASA officials had failed to take any number of steps during the mission that might have alerted them to the risks the seven-member crew faced when the shuttle reentered Earth’s atmosphere, the board said.

Engineers quickly recognized that a large piece of foam had fallen off the external tank 81 seconds after liftoff Jan. 16 and struck the orbiter. Five days later, more than 20 engineers assessed that event at a meeting at Johnson Space Center, Ride said.

The panel included photographic, aerodynamic and thermal protection experts, all of whom had key roles in determining whether the foam could have damaged the orbiter. Panel members concluded that there were too many uncertainties and that fresh photographs of Columbia could help, Ride said. Such photos would be taken either from Defense Department ground telescopes or spy satellites.

But the request never went forward, Ride said.

“Now the question is why didn’t that request make it to program managers and up into the system,” she said. “It is too early to characterize all the places that broke down.”

Ride said missed communications and a failure of some officials to understand the importance of photographs played a role in the breakdown.

The errors in recognizing the peril facing Columbia continued, as NASA relied on a flawed computer model, known as Crater, to assess the potential damage to thermal protection tiles from foam debris.

“Neither NASA nor the board is satisfied with the model,” board Chairman Harold W. Gehman Jr. said. “It has a lot of limitations. It is not a computation model. It is not a predictive model.”

Boeing Co. engineers were also called into the analysis and they produced a report that predicted a “safe return” for Columbia. That flawed recommendation then “flavored” all of the subsequent decisions that NASA made in deciding that the orbiter had not been damaged. Regardless of the outcome of the investigation, it now appears that Boeing’s conclusions were incorrect, Gehman said.

“Obviously, it was wrong, but that is hindsight,” he said.