The Columbia Accident Investigation Board included in its 29 recommendations fundamental changes in NASA's way of doing business.
The board found NASA's culture highly resistant to change, and cited parallels between the causes of the space shuttle Challenger disaster 17 years ago and the fateful end on Feb. 1 to the Columbia mission.
NASA had pledged to change, and did for a time, but eventually drifted back to its old ways, the report found.
By the time Columbia was launched last January, "NASA retained too many negative. . . aspects of its traditional culture," according to the report.
Some of those negative aspects included flawed decision-making and a tolerance by managers of abnormal events, such as the shedding of foam insulation from the shuttle's external fuel tank during launch, according to the report.
Communication was stifled in NASA, and the safety program often was "silent" because engineers with safety concerns were intimidated into silence, the report said.
"We get it," NASA Administrator Sean O'Keefe said in response to the report. "We've got to take great heart and stock" in the board's point that top NASA managers must do a better job communicating that safety is still their number one priority, he said.
The board's chairman, Retired Navy Admiral Harold Gehman, Jr., said the culture change recommendations require both leadership and organization reforms, and are harder to do than the technical repairs that must be made on the space shuttle.
NASA officials have set a goal of resuming shuttle missions next spring, but they admit their timetable might be overly optimistic given the investigation board's scathing critique.