A special U.S. space agency task force Thursday begins overseeing NASA's efforts to get the grounded space shuttle fleet flying again after the Columbia disaster. The panel's job is to advise NASA on how to carry out recommendations soon to be made by accident investigators.

The independent investigators are expected to issue their report later this month recommending technical and bureaucratic improvements NASA can make to return shuttles to flight more safely.

The outside group that will help the agency implement those recommendations is led by former astronauts Thomas Stafford and Richard Covey. They are backed by aerospace and safety experts as well as former high-level military and civilian government officials.

The Stafford-Covey task force holds its first meeting at the shuttle launch center in Florida on Thursday. In the next few weeks, it will become acquainted with current shuttle operations and meet members of the Columbia Accident Investigation Board.

The investigators have already issued five proposals to help NASA get an early start on returning shuttles to flight. But without having seen the rest of the suggestions yet, NASA officials are not promising to follow them precisely. Still, the agency's deputy administrator, Fred Gregory, says they will not challenge them, either.

"I think that we will be responding almost to the letter the recommendations of the board. Now, the board has not published the report yet and I may have to back off a little bit," he pointed out. "But what we will do is the right thing. That's why we have the Stafford-Covey team there independently assessing our response to the board."

NASA has set March as a potential time to re-launch shuttles. But Mr. Gregory indicates that this is not a firm deadline. He stresses that the agency will be guided not by the calendar but by the work it must do to carry out the investigators' recommendations.

"We're going to be listening extremely carefully to the Stafford-Covey task group. We will not fly until we are ready to, [until] we have had assurance from the task group that we are headed down the right road, that we have not missed anything," he said.

The five proposals that the Columbia accident board has already issued call on NASA to get better pictures of shuttles during launch and in flight, develop a system for astronauts to inspect and repair damage in orbit, and improve inspection of shuttle wings between missions.

The board believes it was wing damage that doomed Columbia. It says hard insulating foam that broke away from the shuttle's external fuel tank at launch smashed through the brittle front edge of the left wing. This allowed searing atmospheric gases to penetrate and melt the wing upon re-entry.

NASA has begun taking steps to ensure foam never endangers another shuttle. The agency official in charge of human space missions, Bill Readdy, says the material will be removed from the region on external fuel tanks where it peeled away and will be replaced by heaters. This is necessary to prevent ice formation on the tanks. The tanks are cold because frigid temperatures are needed to keep their hydrogen and oxygen fuel in liquid form.

"You have very, very cold temperatures and the moist air here in Florida," said Mr. Readdy. "If ice were to form, then as it sheds during ascent, that would be a problem, impacting the vehicle potentially.

Mr. Readdy says other changes recommended by the investigators will make the shuttle program smarter, stronger, and safer.