Top NASA officials made it clear Thursday that Morton Thiokol's Wasatch Operations will be phased out of the space shuttle booster business sometime between 1994 and 1997.

Adm. Richard H. Truly, shuttle program director, told the House Space Committee that NASA expects to choose a contractor by January 1989 to produce an advanced design of the solid rocket motors that will carry future shuttles aloft.But Morton Thiokol's Wasatch Operations apparently does not figure into the equation. "Putting the plant at the Morton Thiokol Wasatch Division is not an option," Truly told committee members.

Morton Thiokol spokesman Rocky Raab said company officials were not prepared to comment on NASA's intentions Thursday morning.

In a recent interview, however, John Thirkill, vice president of Morton Thiokol's Space Operations, did criticize NASA's plans to build a new booster rocket facility.

"It's just not a smart thing to do," Thirkill said. "I think it would be a step toward nationalizing our industry . . . . My sense is that they (NASA) would just like to be in control."

All indications are that the redesigned motors will be manufactured at a new sight on the Gulf Coast. J.R. Thompson, director of the Marshall Space Flight Center in Alabama, said the three leading sites were at Cape Canaveral, Fla., itself; Yellow Creek, Miss., and the National Space Technology Lab in Alabama. All have access to gulf waters.

The controversy over whether the new booster plant is owned by the government or by the contractor is still under review by the Office of Management and Budget and a decision is expected within days, Thompson said.

He estimated the cost of the new facility at $450 million, including the plant and its equipment. But he stressed the government would be committed to building the new facility whatever the cost. "NASA is committed to a new facility," Thompson said.

About 2,500 employees are currently employed in Morton Thiokol's booster rocket program at Wasatch Operations, 25 miles west of Brigham City.

Truly said $27 million in the fiscal 1989 NASA budget, which NASA officials originally earmarked for review of booster plans, is now committed for design and initial construction of the new booster plant. He said the agency expects to add $65 million from next year's budget to fund the project.

Truly said a request for proposals to build the plant will be issued in June and a contractor selected in January.