CAPE CANAVERAL, FLA., FEB. 8 -- A Delta rocket thundered toward orbit today carrying an array of exotic sensors and satellites to be ejected and watched from space in the most complex "Star Wars" space test ever attempted.

The 116-foot unmanned NASA rocket, called Delta 181, lifted off at 5:07 p.m. EST from the Cape Canaveral Air Force Station.

The $250 million flight was NASA's first major mission since last March 26 when an Atlas-Centaur rocket carrying a military communications satellite was destroyed by lightning during launch in a thunderstorm.

The Delta 181 mission was delayed from last Thursday because of problems with ground equipment.

The rocket's second stage carried a complex 6,000-pound instrument package, the heaviest payload ever carried by a Delta rocket, loaded with sensors and 15 small subsatellites that were to be ejected in space during the planned 12-hour, eight-orbit mission.

The flight, the second in a series of "Star Wars" Delta missions, was considered the most complex mission ever attempted by the Strategic Defense Initiative, the multibillion dollar effort to develop a space-based defense against Soviet missiles. Another SDI Delta flight is planned for later this year.

The mission's primary goal is to determine how well the space sensors can distinguish between the small satellites, which were designed to masquerade as Soviet nuclear warheads and potential warhead decoys. Making such distinctions is considered crucial to the success of a "Star Wars" missile defense, because space-based weapons will be unable to shoot at everything they detect.

Army Col. Raymond Ross, a top SDI official, said the payload "will perform over 200 complex maneuvers while conducting sensing operations . . . related to the detection and tracking of ballistic missiles."

Ross said the mission was within the bounds of current treaties with the Soviet Union.

Some 100 ground-based radars and aircraft around the world are primed to monitor the mission.