Morton Thiokol will become surprisingly - a major subcontractor in the $1.1 billion, seven-year project to build a new generation of boosters for the space shuttle, NASA announced Friday.

The new Advanced Solid Rocket Motors - which NASA says is needed to carry heavier payloads necessary to build the space station and launch missions toward Mars - will replace the boosters now made by Morton Thiokol in Brigham City, and will be built at a government-owned plant in Yellow Creek, Miss.NASA announced Friday that Lockheed Missile Systems of Sunnyvale, Calif., will become the main contractor to design, build and operate that plant - but Morton Thiokol is among six major contractors who will participate in the project.

NASA officials, however, could not provide details of exactly what type of work Morton Thiokol will perform nor how much money it may mean for the Brigham City operations.

Morton Thiokol chose not to bid to become the main contractor itself for the new boosters, focusing its attention instead on the redesign of the present motors - required after the 1986 Challenger disaster. Morton Thiokol will continue to build the present boosters through the mid-1990s.

Last month, NASA's independent Aerospace Safety Advisory Panel said NASA would be wiser to continue to use the present boosters than to build new ones.

The panel said the new Mississippi boosters could take years and billions of dollars to achieve the reliability of the Morton Thiokol boosters. But NASA officials said they had debated the issue at length already, and determined the new boosters are needed.

The good news for Morton Thiokol on Friday was bad news for Hercules in Magna.

Hercules had teamed with Atlantic Research, Martin Marietta's Michaud unit and Bechtel as the major bidding group against Lockheed for the $1.1 billion contract.

Hercules' director of public affairs, Jack DeMann, said Hercules and its bidding partner, Atlantic Research Corp., Gainesville, Va., naturally are disappointed and will seek a meeting as soon as possible with NASA to find out why they lost.

Even if Hercules and Atlantic had won the contract, most of the jobs would have been created outside Utah, because NASA decided after the Challenger disaster to construct its own plant in Mississippi rather than have the new boosters built at a contractor site, DeMann noted.

The Hercules spokesman said he doesn't know yet whether his company will be able to get any of the subcontracts for the advanced solid rocket motor boosters.

But Thiokol will be a major subcontractor for the winning Lockheed-Aerojet contractors.

"We've been selected as a subcontractor to the Lockheed-Aerojet team for nozzle production - nozzle fabrication," said Rocky Raab, Thiokol manager of external affairs. "We will also be responsible for engineering test-firings and the initial training of manufacturing and test personnel for those firings."

He said the dollar value of the subcontract and the number of jobs it will produce are not clear yet, but the majority of the work will be done outside Utah.

Thiokol announced last June it would not bid on the overall booster contract. But Raab said that several weeks after the announcement, Lockheed and Aerojet approached the company about being a subcontractor, and Thiokol submitted a proposal.

Raab said the dollar value of the proposal is considered proprietary information until after Hercules and Aerojet finish negotiating with NASA and then with the subcontractors.

NASA said Friday the first contract with Lockheed will be to design, develop, test, evaluate and build 12 advanced solid rocket motors, and to construct the Mississippi plant.

It will also include an option for production of up to an additional 88 advanced motors.

Lockheed's prime subcontractor is Aerojet Space Booster Co. of Sacramento, Calif.

Other subcontractors include Morton Thiokol, Brigham City; Aerojet Solid Propulsion Co., Sacremento; Babcock and Wilcox, Barberton, Ohio; Lockheed Austin Division, Austin, Texas; and Rust International.

Besides building the main facility in Yellow Creek, NASA said additional facilities for the booster are planned at the John C. Stennis Space Center near St. Louis, Miss., for ground testing.

NASA said schedules call for the delivery of the first advanced boosters in 1994. It plans to phase them in over a three-year period, when the new boosters will be tested during six different missions.