Focuses on Picking Real Warheads From Soviet Decoys : Satellite Orbited in Key ‘Star Wars’ Test

The Defense Department on Monday successfully lofted into orbit a major “Star Wars” experiment, a $250-million test that is vital to the early deployment of a missile defense system, Pentagon officials said.

The Pentagon called the experiment, code-named Delta 181, “one of the most complex unmanned Earth orbit space missions ever attempted by the United States.”

A Delta rocket lifted a 6,000-pound satellite complex off a launch pad at Cape Canaveral Air Force Station in Florida late Monday afternoon. Within an hour, officials said they had received early signs that the satellite’s sensors had begun to operate on schedule.

Thousands of Pictures

In 12 hours of intense space maneuvers to follow the launch, the test was intended to gather crucial data in the form of thousands of pictures. The satellite complex will expel mock warheads and photograph them in an effort to gather information on what Soviet nuclear warheads would look like as they hurtle through space.

Such information is critical for a weapon that is the Reagan Administration’s leading candidate for early deployment in the program to establish a missile defense. The weapon, known as a “kinetic kill vehicle,” is essentially a shard of metal fired at a nuclear warhead.

The launch was the second major “Star Wars” project to be lofted into space on a Delta rocket. The first experiment, conducted in September, 1986, involved a test of the kinetic kill vehicle’s homing device, firing at a target in space.

Today’s experiment will further refine the earlier project, enabling the weapon to distinguish decoy warheads that the Soviets could mix with real ones. The ability to identify and destroy nuclear warheads outside the atmosphere “is the long pole in the tent” of strategic defenses, said a Pentagon official who spoke on condition of anonymity.

Charge Breach of Limits

Critics of the Administration’s anti-missile program, known formally as the Strategic Defense Initiative, have charged that some space tests, such as that launched Monday, have breached the legal limits of the U.S.-Soviet Anti-Ballistic Missile Treaty, which has restricted the development or deployment of missile defenses since 1972.

The Defense Department, however, said that the Delta 181 experiment is in full compliance with the superpower accord.

Maj. William O’Connell, a Pentagon spokesman, said that a special Defense Department group, as well as other federal agencies, had reviewed the experiment to ensure that it complied with all current treaties. Congress was notified of plans for the experiment and filed no formal opposition.

A successful test of the system’s sensors would keep the project on track toward phased deployment of a missile defense system, an approach championed by Defense Secretary Frank C. Carlucci and his predecessor, Caspar W. Weinberger.

Many conservatives in the Administration and in Congress are pressing deployment of missile defense systems as soon as each phase is technically feasible, rather than waiting to deploy all stages at once. They hope that a “Star Wars” project that has already gotten under way will discourage future administrations from abandoning or dismantling the program.

Seen as Prelude to Lasers

In the longer run, the information gathered by Delta 181 also could provide crucial information for more ambitious “Star Wars” technologies, such as lasers intended to intercept Soviet warheads just after they have left the Earth’s atmosphere.

“It’s key that we have that data,” the Pentagon official said.

The test originally was planned for last Thursday but was scrubbed after the Delta rocket developed technical problems.