The space agency needs all three of its orbiters to support the international space station. Thus, when it returns to flight, NASA must have far greater confidence in the reliability of the system than at any time since flights began in 1981.
"To the public, the astronauts are still heroes," Loeb said. "It is important to this country. And there are questions about whether we should have manned versus unmanned spaceflight. Therefore, there is a need to determine what happened."
To make that determination, the Columbia Accident Investigation Board, the formal group appointed to determine the cause, has said it is "leaving no stone unturned." It is reviewing millions of pages of documents, sending members to manufacturing plants and government laboratories all over the country, and ordering a range of laboratory tests. It is also holding a series of public hearings to take testimony and gather evidence.
The board has not given an overall cost estimate or a timetable for its investigation, said spokeswoman Laura Brown. In many conversations that retired Adm. Harold W. Gehman Jr., who is heading the investigation, has had with members of Congress, they have expressed support for the board's efforts, Brown said.
"The admiral is very conscious of cost issues," Brown added.
The board is operating with $10 million from a $50-million appropriation by Congress after the Feb. 1 accident. The other $40 million is being held by NASA to cover its costs. The money, however, is not paying for the salaries of government employees assigned to the investigation. The board includes a number of high-ranking military officers and civil service employees, whose salaries are borne by their own services.
As the investigation pushes forward, the federal government must bear the expense of maintaining the program, with its nationwide workforce of 17,000, while the shuttle remains grounded -- a tab that could run as much as $10 million per day. Many of those employees are continuing their normal activities that involve maintaining the orbiters and preparing for future missions, said NASA spokesman James Hartsfield.
The total cost also does not include potentially expensive modifications to the space shuttle and institutional changes at NASA that may result from the board's recommendations. Nor does it include the loss of the orbiter itself, which originally cost about $2 billion to manufacture nearly 25 years ago.
