An article Saturday about layoffs at the Kennedy Space Center incorrectly described the actions of Planning Research Corp. of McLean. PRC is laying off about one-third of its work force in a move the company said is not related to the space shuttle accident.

Space agency officials announced today that 1,100 space shuttle workers here will be laid off or transferred and thousands more will lose overtime in the largest NASA cutback since the Apollo moon program ended in 1970.

The cutbacks, affecting about 10 percent of the shuttle work force, will hit hardest among the engineers, technicians and others employed by Lockheed Space Operations Center, the shuttle's main contractor. But employes of three other companies that work on the shuttle program here -- McDonnell Douglas Astronautics Co., Boeing Aerospace Operations, and Planning Research Corp. -- will also be affected. PRC, based in McLean, Va., will lay off 150 people, virtually all its staff here.

Officials of the National Aeronautics and Space Administration also said that today's announcement may not be the only economic consequence of the Jan. 28 explosion of the shuttle Challenger. Thomas E. Utsman, deputy director of the Kennedy Space Center here, said there will be layoffs at other NASA centers and that the cutbacks here could become more severe if the investigation of the Challenger explosion delays the shuttle program "significantly" more than a year.

News of the layoffs -- combined with fears of more to follow -- jolted the coastal community surrounding the cape, an area known as the "Space Coast" because of its dependence on the space program. "There's a lot of uncertainty and apprehension," said Truman Scarborough, mayor of Titusville. "There's no question this is going to hurt -- it's only a question of how much."

NASA officials said 650 layoffs were scheduled to occur anyway, after the completion earlier this year of work on a new launch pad. In fact, the officials said, affected workers would have been informed about three weeks ago had it not been for the Challenger disaster.

Instead, those layoffs were delayed and announced today together with 450 cutbacks -- including some by attrition and transfers -- resulting from the Challenger explosion. The twin reductions will reduce the total work force here from about 16,000 to 14,900. Although cutbacks were ordered "across the board," officials said senior engineers and managers probably would be least affected in order that NASA does not lose the technical skills needed to restart the shuttle program.

NASA had planned 14 shuttle launches this year and 19 next year. Though the program has been put on hold, NASA says significant work can be done in the meantime.

"We're essentially going to be processing vehicles, short of flying them," said Robert Sieck, director of shuttle management. "We don't see us polishing doorknobs."