Along with the technical causes of the shuttle's demise, the board's final report, expected this summer, will include details of the agency's flawed processes and recommendations for eliminating future oversights.
Harold Gehman, head of the 13-member panel tasked to investigate the fatal Feb. 1 accident, said his team had found examples of other potentially dangerous problems that had not set off NASA's safety alarms.
Columbia's destruction is thought to have been caused by a piece of foam insulation that fell off the shuttle's fuel tank at launch and damaged the leading edge of the spacecraft's left wing. Sixteen days later, as the shuttle and its seven-member crew began re-entering the atmosphere for landing, superheated air penetrated the wing through a breach, melting its aluminum structure from the inside. The wing deformed and the ship was torn apart by atmospheric forces.
During its investigation, the Gehman commission found foam had broken off and hit the shuttle on every launch, with each orbiter returning from space with an average of 30 impacts on its heat-resistant tiles that are at least an inch in diameter.
On at least six occasions including Columbia's last launch, part or all of the hand-formed slope of foam that covers the tank's bipod area broke off, but NASA's safety system failed to see a dangerous trend. Investigators have said the actual number of times the tank shed bi-pod foam likely is much higher, because NASA has no data on dozens of launches that took place at night or when viewings of the bi-pod area were blocked.
"The real question is why did we permit a process that allowed any strikes? That is what we're doing a lot of soul-searching over now," NASA administrator Sean O'Keefe said before the Senate Committee on Commerce, Science and Technology.
Gehman, who was seated next to O'Keefe during hearing, said it is his personal theory NASA failed to spot the trends because its safety and engineering teams do not have the people, money and resources to develop data, rationales and other scientific evidence to support their positions. In the engineering world, he noted, data are currency and without data, technical considerations are difficult if not impossible.
Senate committee chairman John McCain, R-Ariz., icily pointed out that last year $167 million was diverted from NASA's budget to fund pet projects by his fellow Congressmen.
He asked Gehman to include in his report how budget issues factored into the accident.
"We will," he promised. "One-hundred million dollars will buy a whole lot of safety engineers."