The US space shuttle programme, still reeling from February's tragic demise of the Columbia orbiter, has been hit by a major management shake-up, amid indications NASA officials may have failed to act on signs the spaceship was in trouble soon after liftoff.
With key congressional overseers demanding action, the National Aeronautics and Space Administration announced on Wednesday that Ralph Roe, the man in charge of shuttle engineering at the Johnson Space Center in Houston, Texas, is being shipped off to another job.
He is heading to Hampton, Virginia, where he will serve as special assistant to the director NASA's Langley Research Center, a civilian aeronautics laboratory with only a supporting role in the space exploration programme.
The space agency took great pains to avoid any appearance of a demotion, praising Roe as "a success" on all of his previous jobs.
But congressional officials made clear that his departure resulted from direct pressure from the Senate Committee on Commerce, Science and Transportation, whose leaders had demanded that NASA take responsibility for the fiery crash of Columbia, which killed all seven members of its crew.
Although no official announcement has been made, US media reports said on Thursday that also leaving Houston will be Linda Ham, who headed the mission management team during the ill-fated Columbia flight.
The changes follow last month's departure from the Johnson Centre of Ron Dittemore, the shuttle programme manager, and the reassignment of General Roy Bridges, director of the Kennedy Space Center in Florida who was in charge of Columbia's post-liftoff damage assessment. He was dispatched to run the Langley facility.
Columbia disintegrated over the US state of Texas on February 1 as it was headed for landing at Cape Canaveral, Florida, after a mission to the International Space Station.
Investigators believe the tragedy was likely caused by a piece of foam that separated from the external fuel tank after launch and damaged the left wing of the craft.
The damage allowed hot gases to pierce the shuttle's protective shield during descent and ultimately caused its disintegration, according to that theory.
Pictures of the foam hitting Columbia were reviewed by mission managers, but they did not believe the situation warranted any emergency measures.
A panel investigating the Columbia demise also said Tuesday that long-range cameras installed at the Kennedy Space Center were inadequate to provide the best possible data on shuttle launches, which hampered damage evaluation.
As heads rolled, NASA brought in five new managers in the hope that new blood will allow it to quickly restore the wounded manned spaceflight programme to its former splendour.
"This is a critical time for the agency and the shuttle programme and I believe these changes and additions to my staff prepare us to return to flight as soon as possible and, most importantly, as safely as possible," said Bill Parsons, the new programme manager who took over from Dittemore.
Replacing Roe will be Steve Poulos, a specialist in thermal systems who has been with NASA since 1989, the announcement said.
Wayne Hale, one of the experts from the Kennedy Space Center who tried and failed to persuade his superiors to enlist the military in helping NASA make high-resolution pictures of Columbia to assess possible damage from the foam, has become deputy manager of the shuttle programme.
Also joining the management team will be Edward Mango, a specialist from the Kennedy center, John Shannon, a liaison between NASA and Columbia crash investigators, and John Muratore, one of the top engineers in Houston.