NASA announced yesterday the abrupt retirement of Lawrence B. Mulloy, the proud, unrepentant career manager who took the brunt of the criticism in the Rogers Commission report on the Challenger accident.

Mulloy plans to retire Friday after more than 30 years of government service, the space agency said.

The 52-year-old veteran of the National Aeronautics and Space Administration was in charge of the faulty solid rocket boosters that destroyed Challenger on Jan. 28. He was among those who argued the night before the launch that cold weather was not a significant factor and pushed for a "go" over the objections of engineers.

The report of the presidential commission headed by William P. Rogers repeatedly faulted Mulloy's judgment and his failure to correct the boosters' known design and performance problems. It suggested that the commissioners believed that Mulloy lied in his testimony to them. Mulloy has strenuously denied the charge.

Mulloy's decision to retire came after NASA Administrator James C. Fletcher had decided to move him from Marshall Space Flight Center in Huntsville, Ala., to Washington headquarters as deputy director of the propulsion, power and energy division office of aeronautics and space technology. "The agency decided the job in Washington would make the best use of his talents," said NASA spokesman Ed Medal at Marshall. "He has a wealth of experience and has certainly been regarded as a very capable manager."

Mulloy declined the job, officials said. Two months ago, in what officials described as a "lateral transfer," Mulloy had been moved from his post as head of the rocket program to another job at Marshall.

This week, he and NASA were named in a $15.1 million negligence claim by the family of one of the seven crew members killed in the accident.

Mulloy, who has spent his entire career sending U.S. rockets into space, maintained a defiant posture from the moment of the accident.

His long, jargon-filled answers to simple questions often exasperated commission members, who questioned him with increasing anger. They also said that he and others at Marshall were uncooperative in providing documents the commission requested. Long after investigators had requested "everything" related to the accident, they discovered Marshall documents indicating that Mulloy had grounded the shuttle because of booster problems, then signed a waiver for each flight.

More than four months after the accident, and two days after the commission released its findings, Mulloy acknowledged for the first time in an interview that his actions were mistaken. "Looking back in hindsight, there is a point . . . where I think we took a step too far," he told The Washington Post, adding that he just "wasn't smart enough" to perceive the gravity of the booster problems.

But he also defended himself to the end, arguing that he had "functioned responsibly" and that he should not be held individually responsible for his decisions because they were subject to "three other levels" of management review. He noted, as did the commission, that his superiors also failed to respond effectively to knowledge available to them.

He is the third Marshall manager to retire after being involved in key decisions about Challenger. Marshall Space Center Director William R. Lucas, who was told of engineers' objections to the launch, and George B. Hardy, a senior engineer who argued in favor of launching, retired recently.

Mulloy would be eligible for regular retirement in three years and his early departure "reduces his annuity somewhat," Marshall officials said. Mulloy began his government career in the Army after graduating from high school and later obtained degrees in engineering and public administration.

Officials said Mulloy gave no reason for his decision and took sick leave yesterday, declining to talk to reporters.

Special correspondent Charles Fishman contributed to this report.