Shuttle program officials Wayne Hale, Linda Ham, Ron Dittemore and Ralph Roe at Kennedy Space Center today. Photo: NASA

Sources close to the investigation told CBS News today that Dittemore, who inspected debris today at the Kennedy Space Center, was not among the names submitted to O'Keefe. Two sources said the list included Linda Ham, a former flight director and the head of NASA's mission management team, and Ralph Roe, a former launch director and manager of the shuttle program's vehicle engineering office at the Johnson Space Center in Houston. It is not yet known if the board requested any additional reassignments.

A source said the request for reassignments was not meant as a reflection on anyone's personal integrity, it was simply in keeping with a desire to ensure the independence of the ongoing investigation.

As chairman of the MMT, Ham ultimately accepted the results of a Boeing analysis of the potential damage to Columbia's left wing from the impact of foam debris from the ship's external tank 81 seconds after launch. The analysis concluded Columbia's wing might suffer significant damage during re-entry, but that even so, the vehicle could safely land.

Ham presumably played a role in a decision not to request a detailed photo survey of Columbia's underside using powerful Air Force telescopes. Wayne Hale, a senior flight director now serving as launch integration manager at the Kennedy Space Center, made inquiries about the possibility of Air Force help inspecting Columbia, but those initial efforts were terminated by senior management.

"The SSP (space shuttle program) did not want any data and in fact there was never a formal MOD (mission operations directorate) request made from the FDOs (flight dynamics officers) or the Flight Director," Steve Stich, a flight director himself, wrote in an email to a colleague.

In an interview today to discuss various aspects of hypersonic flight, Hale declined comment on the matter, saying "I probably ought to wait until I tell the board my story. That's coming up."

In the days following the disaster, Dittemore said the program did not request Air Force assistance inspecting Columbia because engineers did not believe the optical systems, as powerful as they might be, could show enough detail to resolve the kind of damage expected from the foam impact.

But as the investigation wears on, critics of that decision argue (with 20-20 hindsight) that a photographic inspection of Columbia in orbit might have revealed enough detail to at least point investigators toward the area of the wing where the failure originated.