NASA administrator Richard H. Truly told a new panel on the space program's future yesterday that his agency has serious problems -- but they are not what most outsiders think they are.

"All is not well," Truly told the Advisory Committee on the Future of the U.S. Space Program. But he and his top lieutenants vigorously defended the National Aeronautics and Space Administration's recently overhauled management structure, a primary focus of the new group.

Truly said the real problems, from his perspective, include his need for more authority and flexibility to run the program and "a better match" between NASA's programs and its resources. He cited "government-wide management practices" that limit managers' ability to move money and people and to procure services needed to carry out programs.

He also said he is concerned that the public does not understand the purpose of the proposed Space Station Freedom, NASA's most controversial project.

The well-publicized technical problems such as power and weight excesses uncovered by NASA engineers during the summer, he said, "are either solved or on the way to a solution" and, after a period of serious management instability, the program is now run by "one of NASA's best big-program managers."

"Yet public understanding is to the contrary," he said.

In a marathon that stretched from 8 a.m. to around 7 p.m., the panel's sometimes-pointed questioning focused on NASA's complicated -- some say Byzantine -- management structure, which has been a target of concern for many in the aerospace community and has been blamed by some for problems ranging from the space station's troubles to the shuttle hydrogen leaks.

Panel chairman Norman Augustine, chief executive officer of Martin Marietta Corp., indicated the panel will zero-in on NASA's preliminary design and systems engineering practices, and on the independence of its costs and scheduling assessments.

Yesterday's session, and those planned today and Saturday, were described as "fact-finding" discussions to provide the panel with a common perspective on where NASA stands today.

Augustine promised that the panel's approach will be "very broad, very penetrating, very independent and constructive, and forward-looking."

Although there is broad support for the space program, he said, "it seems no two people support the same space program. So the challenge is to do what we think is right, and let the chips fall where they may."

Augustine's point about the lack of consensus on the space program was illustrated repeatedly during the debate at NASA headquarters. Frequently, the panel members -- including representatives of the scientific community, industry, the Defense Department and academia, as well as former NASA officials -- disagreed with each other, as well as with Truly and his deputies.

The committee was created as the result of concern in the Bush administration about NASA's credibility in the wake of a series of problems this summer, including a major flaw discovered in the Hubble Space Telescope and the halt of space shuttle flights since April by a plague of hydrogen leaks.

The committee's value has been questioned because it is made up primarily of aerospace veterans and will report first to Truly, then to the National Space Council chaired by Vice President Quayle.

But some insiders say the panel is under pressure to produce constructive results because the president, who has invested a good deal of political capital on an ambitious space exploration program, wants a space agency that can carry it out.

Mark Albrecht, Space Council staff director, fielded questions from the panel about the sometimes conflicting roles of NASA and the council, which advises the president on space policy.

"The president has asked all of us to think big and challenge the system," he said, in order to prepare for a new era of "sustained operations in space. The era of brief space encounters is ending."