The Columbia Accident Investigation Board (CAIB) report said a piece of foam that broke off during take off pierced the shuttle's protective skin causing the overheating that led to the breakup as Columbia re-entered the Earth's atmosphere on February 1.

All seven astronauts on board, including the first Israeli in space, were killed.

But the board's report highlighted "organizational compromises" and managerial oversights at the National Aeronautics and Space Administration (NASA) that failed to heed alarm bells.

"We are convinced that the management practices overseeing the Space Shuttle Program were as much a cause of the accident as the foam that struck the left wing," the report said.

Too few staff, budgetary constraints and dated equipment also contributed to the disaster, the report concluded.

Despite the cricitisms, the CAIB said the shuttle program should resume as soon as new safety recommendations have been carried out.

"The shuttle program remains central to US ambitions in space," said the 13-person board led by Harold Gehman, a retired admiral.

Gehman said there had been no pressure put on the committee to conclude that the space shuttle had to continue.

The CAIB found concerns expressed by NASA engineers about pending doom on the space shuttle were ignored by senior managers.

It said shuttle managers ignored incidents of pieces of foam flying off on prior missions and that there was inadequate camera observation of Columbia's launch.

The report said this time, Columbia's left wing was pierced by a chunk of rogue foam during take-off on January 16.

The hole in the wing caused by the foam's impact allowed super-hot gases to enter the wing as the shuttle returned to Earth. The gas tore the shuttle apart as it entered the earth's atmosphere.

Shortly after Columbia's launch, some technicians requested that a spy satellite survey the shuttle after they had spotted a foam shard hitting Columbia's left wing in launch videos.

"There were three clear requests for better imagery that were ignored," the report said.

Foam shards, from a bipod that linked an external fuel tank to Columbia and other shuttles, had fallen off before during prior launches, and this "conditioned" managers not to see it as safety threat.

Shuttle managers had "become conditioned over time to not regard foam loss or debris as a safety-of-flight concern," the report said. NASA managers thus failed to follow their own rules for investigating potential fatal incidents.

"NASA has not followed its own rules and requirements on foam-shedding."

The inquiry said another shuttle, Atlantis, could have been readied for a rescue mission if it had been realized that Columbia was badly damaged, before day seven of Columbia's mission.

"The Board concludes that NASA's current organization does not provide effective checks and balances, does not have an independent safety program and has not demonstrated the characteristics of a learning organization," it found.

As a consequence, the report recommends Congress establish a permanent, fully-independent, safety team to oversee future NASA shuttle launches.

Aside from calling for improved safety management, the CAIB has also made a series to technical recommendations to Congress in a bid to avoid another disaster.

NASA has already guaranteed that the CAIB's recommendations will be carried out as it strives to get the shuttle program back on course and revive its image.

Columbia was the second shuttle to be lost after the Challenger exploded just after takeoff in 1986.

The report was sent to Congress, the White House, NASA and the families of the seven dead astronauts.

SPACE.WIRE