Morton Thiokol officials - apparently caught off guard by NASA's announcement that the firm's Utah facility will be phased out of the space shuttle booster business sometime between 1994 and 1997 said Friday that the cost of shifting booster construction elsewhere may not be justifiable.

Admiral Richard H. Truly, NASA's associate administrator for space flight, and J.R. Thompson, Marshall Space Flight Center director, made it clear Thursday that the space agency intends to build the next generation of space shuttle boosters somewhere other than at Morton Thiokol's Wasatch Division plant in Utah's Box Elder County.Modernizing Thiokol's facilities to make the shuttle's new advanced solid rocket motor is not an option, they told the House Space Science Committee.

Thiokol, Utah and Box Elder County officials seemed surprised and vowed to fight.

In a brief prepared statement, John Thirkill, vice president of Morton Thiokol's Space Operations said, "While we cannot respond in detail until we have seen the complete text of Admiral Truly's comments, Morton Thiokol believes that an expenditure of $500 million cannot be economically justified when it dupli-cates production capacity that al-ready exists in the solid propulsion industry."

Gov. Norm Bangerter promised to battle to protect Morton Thiokol's interests.

"This is certainly news to me and probably to Morton Thiokol as well," Bangerter said through an aide. The governor vowed to use every avenue available including the offices of Utah's congressional delegation as well as his own to see that NASA's plan doesn't become a reality.

Box Elder County Commissioner Frank Nishiguchi said he is shocked by NASA's stance. "Morton Thiokol has been a tremendous contractor for the Defense Department and NASA itself. I cannot understand this kind of attitude being put forth by them. Morton Thiokol has been a good citizen of Box Elder County and a good contributor to the lifestyle in Box Elder County. I can't help but be disappointed."

Nishiguchi said he hopes NASA will reconsider its decision in light of the efforts Morton Thiokol has made to promote the space program. "We would hope this type of effort would not be overlooked."

Tremonton Mayor Gil Smart said there is no question that such an action would affect the Box Elder County area. "Thiokol has definitely been an important part of our area; the shuttle is and has been an important part of Thiokol. Anything that affects Thiokol affects our area and the entire state."

Tremonton citizens should get behind Thiokol, he said.

Sen. Jake Garn, R-Utah, said he will fight plans to make the new plant a government-owned facility, no matter where it is finally located.

"I haven't thought for a long time that there was any chance it would go at Wasatch," Garn said. "I'm not just protecting Utah. What I'm fighting is too much government."

Sen. Orrin Hatch, R-Utah, received a promise from James C. Miller III, Office of Management and Budget director, that he would "direct Jim Fletcher (NASA's director) to examine thoroughly and pursue vigorously commercial opportunities for the (advanced solid rocket motor) production facility."

Truly made it plain to committee members Thursday that Morton Thiokol's facility 25 miles west of Brigham City doesn't fit in with NASA's plans to produce a new generation of solid rocket motors that will carry future shuttles into space.

"Putting the (new) plant at the Morton Thiokol Wasatch Division is not an option," Truly told the committee.

All indications are that the new generation of motors, which will be designed to carry heavier payloads, will be manufactured at a new site on the Gulf Coast, close enough to Cape Canaveral that big booster engines can be shipped there by water. Thompson, director of the space flight center in Huntsville, Ala., said the three leading sites were at Cape Canaveral, Fla.; Yellow Creek, Miss.; and the National Space Technology Lab, also in Alabama.

Local officials for Hercules Inc. declined to comment on what impact NASA's preference for a Gulf Coast plant might have on the new generation of shuttle boosters being built at their facility in the western Salt Lake Valley.

During their testimony Thursday, the slim, gray-haired Truly and the gruff, pipe-smoking Thompson were questioned sharply by members of the House subcommittee but gave no ground and justified their decision on the basis of safety, economy and control over the advanced solid rocket motor contractor.

NASA plans to issue a request for proposals for the new plant in June and select a contractor in January 1989, Truly said. The plant itself will cost between $200 and $300 million, with machinery and equipment pushing the cost to at least $450 million. He admitted under questioning from Rep. David Nagle, D-Iowa, that the agency will build the facility under a cost plus $1 contract that may be subject to overruns.

The agency has $27 million in its fiscal year 1989 budget for design and initial construction of the new advanced solid rocket motor plant, Truly said, and will seek $65 million next year to continue the project.

NASA would like to build a government-owned, contractor-operated plant so the agency could easily remove a contractor that did not live up to its requirements. That plan flies in the face of the Reagan administration's policy of privatization, or using private industry rather than government organizations.

Both Truly and Thompson conceded that Fletcher had received orders from the White House to "thoroughly examine and vigorously pursue . . . commercial options for the (advanced solid rocket motor) facility."

The Deseret News obtained a copy of a letter from the OMB to Fletcher that said OMB would "withhold apportionment of (advanced solid rocket motor) facility funds until this is done satisfactorily."

Thompson, however, said after Thursday's hearing that he expects the OMB order to be "disposed of . . . within days . . . by some wordsmithing."

OMB Associate Director Robert K. Dawson directed the NASA officials to include commercial options in their testimony before the subcommittee, chaired by Rep. Bill Nelson, D-Fla. While they did that, both Truly and Thompson left no question that they believe the government will own the new plant.

Nelson questioned whether using government money up front for the plant would be wise in light of possible budget problems that might force NASA to cut back other space programs in the future.

The plant NASA wants would be heavily computer-operated, eliminating present "1950s technology" handwork that Thompson said is less reliable.

He added, in response to a reporter's question, that "We haven't had any political pressure at all. I don't think we would pay any attention to it if we did."

Hercules recently joined forces with the Virginia-based Atlantic Research Corp. to compete for development and production of the new booster design. Others among the five large solid-fuel manufacturing companies, including United Technologies Co., Aerojet-General and Hercules Inc., will also be invited to bid.

Production of redesigned solid rocket motors at the Wasatch Division will continue until about 1996, with the last flight of that motor scheduled for 1997.

The advanced motors will give the space shuttle a payload boost of about 12,000 pounds per mission. They are to have joints that tend to close rather than open when the motor is fired, eliminating a cause of leakage. They will have fewer joints and more welded seams. By being more strongly built, the shuttle's main engines will not have to be throttled back at peak dynamic pressure during a flight.