The program to redesign the space shuttle's solid-rocket boosters will be over budget by $80 million to $100 million this year if managers do not revise testing, contingency planning, manpower or other areas, a National Aeronautics and Space Administration review reveals.

Shuttle program manager Arnold Aldrich and other officials yesterday confirmed that changes will have to be made in the program but emphasized that this alone would not jeopardize a safe return to flight next summer.

If congressional budget-cutters impose further reductions, however, space shuttle officials said the pace of future shuttle flights could be affected.

"It's a little unsettling to be back in the budget, reassessing it this early in the {fiscal} year," Aldrich said in a telephone interview from Johnson Space Center in Houston.

"But I don't think this alone will affect the schedule for return to flight. . . . This is a projected cost overrun for the year {ahead}, not one that's behind us. It means reworking a plan."

J.R. Thompson, director of Marshall Space Flight Center in Huntsville, Ala., said the $80 million to $100 million overrun of the booster redesign budget, which totaled $250 million, includes everything the contractor, independent experts and others had sought in the budget, plus all contingency plans. "That's not real. The real problem is about $40 million."

The overrun could be cut to $40 million, he said, by eliminating some backup activities initiated before the new design for the boosters had been tested. "It's fortunate that a lot of our test results have come out quite well," he said by telephone from Huntsville.

Thompson said that because shuttle program officials are confident of the new design, work could safely be stopped on alternate designs for seals, joints and other parts of the booster. "It's insurance we bought earlier that we don't need anymore."

The remaining $40 million presumably could be drawn from the shuttle program's contingency fund, he said. There is more than $100 million in the fund, but some is committed to other needs.

For the last three weeks, a team from Marshall, which manages the booster program, has been at Morton Thiokol's Utah plant, where the shuttle boosters are manufactured, reviewing the plan for the current fiscal year.

In addition to the overrun, NASA also faces serious cuts from the federal budget deficit-reduction push on Capitol Hill. If the shuttle program is required to share in the cuts, NASA officials said, they may have to spread out the schedule of future shuttle flights and also delay procuring some hardware.

"My priority is to support first flight, with full safety and not cutting any corners," Aldrich said. "But there could be an impact on the future flight schedule."

Aldrich said decisions on what changes to make will be held off until more is known about the outcome of budget maneuvering in Congress.

The main causes of the unexpected rise in booster program costs, he said, are manpower requirements and hardware procurement.

Morton Thiokol has built up its work force to accommodate the demands of the redesign program, officials said.

A flawed joint design in a shuttle booster caused the January 1986 destruction of the shuttle Challenger and death of seven crew members.

"I don't know if the public realizes the extent of the total recovery program," said a source close to the process, citing the high costs of the new emphasis on safety. "It takes people to look at the enormous amount of paper work generated. It takes engineers to do these reviews."

Some of the increase was the result of safety measures recommended by an independent panel of the National Research Council, set up last year to monitor the redesign effort. "We've taken all their recommendations and done what we thought best," Aldrich said. "We haven't been driven anyplace we didn't want to go."

The research council panel earlier this week recommended that NASA expand its booster test program in the interest of safety.

Thompson said this might be accomplished by building more objectives into a given test and doing "more testing with fewer tests."