Soviets Mull O.C. ‘Star Wars’ Visit : Arms: Pentagon awaits formal reply on invitation to tour TRW facility outside San Clemente. Showing a delegation the key ‘alpha’ laser might be a problem.

Soviet officials have responded favorably to an invitation from the U.S. government to tour a top-secret “Star Wars” laser research facility in South Orange County, a military official said Tuesday.

However, the Department of Defense does not expect a formal reply until after President Bush and Soviet leader Mikhail S. Gorbachev meet in an informal superpower summit next month, government officials said.

“The way the State Department has described it to me is that the Soviets responded favorably, but they have not given us a (formal) answer yet,” said Lt. Col. Alan R. Freitag, spokesman for the Strategic Defense Initiative Organization at the Pentagon. SDI is commonly known as the Star Wars space defense plan.

Privately, several officials said they anticipate that an official Soviet response to the 2-month-old invitation will await the conclusion of the meetings between Bush and Gorbachev on Dec. 2 and 3 aboard ships in the Mediterranean Sea off the coast of Malta.

Described as informal and unstructured, the meetings are intended to pave the way for a formal summit meeting next year focusing on arms control.

Despite the uncertainty over the Soviet response, the Pentagon is proceeding with plans for a visit by Soviet scientists and technicians to the laser research unit operated by TRW Inc. on a 2,000-acre site on Avenida Pico just outside San Clemente, north of Interstate 5.

“We’re working out the details” in anticipation of a visit, Freitag said.

Among the problems to be resolved, he said, is the difficulty of accommodating a delegation of scientists, with interpreters, in a “clean room” at the SDI facility that is designed to handle fewer than five people at a time.

The room is the home of a small but powerful “alpha” laser that is a centerpiece of the Star Wars program. “That poses a serious challenge,” Freitag said.

TRW is conducting laser research at the facility under a contract with the Department of Defense estimated to be worth about $200 million. TRW officials were not immediately available for comment.

As proposed by former President Ronald Reagan in 1983, SDI would include a shield of satellite-based lasers to deflect and destroy incoming ballistic missiles carrying nuclear warheads.

However, in recent months members of the Bush Administration have lowered significantly the official expectations for the program. Instead of covering the nation with an impenetrable blanket, such officials as Secretary of Defense Dick Cheney now acknowledge that SDI would offer only partial protection against invading missiles.

But even partial protection would be invaluable, Cheney said in August, because it would complicate the job of Soviet war planners who would not know how many or which of their missiles would reach their targets.

In addition to touring the South County laboratory--which is on county land but is called TRW Systems Group-Capistrano Facility--the Soviets have also been invited to tour another SDI research facility at Los Alamos Laboratory in New Mexico. The invitation was extended by Secretary of State James A. Baker III during a meeting with Soviet Foreign Minister Eduard Shevardnadze in Jackson Hole, Wyo.

The invitation was extended with the hope that the Soviets would reciprocate, a top U.S. arms control negotiator said at the time.

“These aren’t just any two laboratories,” said one government official who asked not to be named. “These are two that the Soviets were specifically interested in and had concerns about.”

Congress has approved a Department of Defense spending bill that cut money for the SDI program from $4.1 billion in the 1989 fiscal year to $3.8 billion this year. Of that, $3.57 billion goes to the Pentagon’s Strategic Defense Initiative Organization, while the balance will pay for SDI work at the Department of Energy.

It is too early to say whether the cuts will affect the San Juan Capistrano research unit, Freitag said.

“There are meetings going on as we speak,” he said. “It started in earnest last week. Now we’re getting down to some very specific funding decisions.”