The space agency's acting chief has dismissed the top-ranked professional approved by the White House to handle the day-to-day operation of NASA during the search for a new administrator, apparently in an effort to consolidate his hold over the agency during the probe of the Challenger disaster.

Acting NASA administrator William R. Graham announced Saturday night that Philip E. Culbertson, a 20-year veteran, has been relieved of duties as general manager of the National Aeronautics and Space Administration, effective immediately.

And in a new development in the search for debris from the space shuttle explosion, NASA officials at Cape Canaveral said yesterday they believe that "components of the right solid rocket booster" have been found by a minisub searching the ocean bottom. Photos taken at 1,200 feet by the submarine will be compared with prelaunch photos of the SRB, the prime suspect in the Jan. 28 explosion that killed seven astronauts and destroyed the $1.4 billion shuttle.

As the investigation continued, Kennedy Space Center officials said that several members of the NASA inquiry board may be eliminated from the Challenger investigation by Saturday's decision of a presidential commission to exclude personnel who helped decide to launch the shuttle. NASA sources said the agency has no idea how many other senior managers may be barred from participating in the Challenger inquiry at any level.

William P. Rogers, chairman of the commission, said Saturday that the decision to launch the shuttle "may have been flawed," and that any officials who participated in the launch decision should be barred from participating in NASA's internal probe. But spokesmen refused to elaborate on that statement yesterday.

Four members of the eight-member NASA "interim investigation team" -- Jesse W. Moore, associate administrator for space flight; Arnold Aldridge, manager of the shuttle program; Richard G. Smith, director of the Kennedy Space Center, and William Lucas, director of the Marshall Space Flight Center -- had directly participated in the decision to launch Challenger, space agency officials said. They are now believed to be ineligible to participate in the probe as a result of Rogers' statement.

In addition, hundreds of NASA and private contractor engineers and technicians in various locations -- the Kennedy Space Center at Cape Canaveral, Mission Control at the Johnson Space Center in Houston, and the Marshall center in Huntsville, Ala. -- would have played some role in the launch decision. At Canaveral itself, more than 100 people -- including officials of NASA and Lockheed, the shuttle's prime contractor -- sit in the "firing room" where the final green light for launch is given.

"There's a certain amount of confusion," said NASA spokesman George Diller. "We don't know how far down in the agency this is supposed to go . . . . Ultimately, there could be hundreds of people affected by this, or it could be as few as a dozen."

Diller said the agency's confusion was compounded because Rogers' statement was issued late Saturday afternoon on a three-day holiday weekend with many NASA officials out of town.

Further highlighting the rising sense of embattlement and conflict within NASA was Graham's ouster of Culbertson, who was widely respected by the professional rocketeers, designers and engineers who have spent their working lives in the space program.

In a brief statement, Graham declared that the position of general manager that Culbertson had filled for two months has "not proved effective." Graham said he will take sole responsibility for all daily and long-range decisions from now on.

"The program managers now will report to the acting administrator directly," the statement said. It said the Challenger explosion had altered the agency's needs, requiring the administrator to consolidate decision-making on such matters as budget needs, launch and payload rescheduling, and the Challenger probe as well.

"A two-tiered senior management structure was proving too cumbersome and slow in the new environment," said the statement, which was released Saturday night by NASA.

Graham was named acting agency head shortly after James M. Beggs, NASA's administrator since 1981, took a leave of absence last December to face charges of fraud unrelated to his NASA activity.

Culbertson was named general manager in a move approved by the White House, which appeared to guarantee Beggs' imprint on the agency and limit Graham's power. Graham, 48, is a NASA neophyte who worked as a Rand Corp. analyst and then headed the White House Advisory Commission on Arms Control and Disarmament.

For the first time in several days, NASA reported progress in the effort to recover pieces of the shuttle and its solid rocket boosters.

A four-man submarine located what agency officials say they believe to be components of the right-hand solid rocket booster -- potentially the most crucial piece of evidence in determining the cause of the explosion.

Pictures of the debris, located 1,200 feet under water about 40 miles northeast of Cape Canaveral, were flown back to the Kennedy Space Center so NASA engineers can compare them with pictures of the booster taken just before the launch. If positive identification is made, the Navy will begin an expensive salvage operation later in the week.