Speaking with reporters at NASA headquarters, Sean O'Keefe said that sort of review would be premature since investigators haven't determined whether concerns among engineers about heat damage during Columbia's fiery descent actually related to the cause of the accident.
"We're not sure what it is that caused this," O'Keefe said, citing the investigation by the board. "When they have decided that, that's when that question gets an answer, with clarity rather than someone's opinion."
NASA has acknowledged previously that these concerns, expressed largely in e-mails and telephone calls during the mission's final days, were never sent to senior mission controllers. The agency has said they were part of an informal "what-if" exercise among some midlevel engineers.
"Is that something to be concerned about? We'll see," said O'Keefe, adding that the context of some of those e-mails is in dispute and can't be resolved until the investigation board announces its conclusions.
"That may put new light on that context that we don't have know," O'Keefe said. "Until then, whatever conclusions you want to draw are based on assumption, theory, how you read it, what the words say."
O'Keefe said he personally discussed the concerns with at least one employee who participated in the e-mail discussions. O'Keefe said the employee, whom he declined to identify, told him engineers were not waving red flags about the imminent destruction of Columbia.
"Nothing could be further from the truth," O'Keefe quoted the employee as saying. O'Keefe bristled when pressed to identify the employee, saying it would "add another log to the fire" and expressing regret that he even mentioned the exchange. O'Keefe on Feb. 25 visited NASA's Langley research facility in Hampton, Va.
William Readdy, the NASA official responsible for the shuttle program, said that in the days since Columbia's breakup, all those who participated in the debate have informally considered how their concerns were handled. But he said there was no formal review by NASA about its decision process.
On Monday, O'Keefe told CBS's "Early Show' the agency "would have spared nothing" to try to save the crew, had any problems been detected with shuttle Columbia.
But he said there was nothing "that supported the concern that something was imminent."
"Had there been any evidence – had there been a sensor that had gone wrong or something - any indication on orbit during the course of that 16-day mission that would have suggested that this was a tragedy in the making we would have spared nothing in order to find a way to avert his disaster," O'Keefe told CBS.