Titan Booster Falls, Bursts Into Flames : Accident: One feared dead and nine are injured in incident at Edwards Air Force Base. Mushroom cloud of smoke was visible for miles.

A section of a Titan 4 rocket booster fell off a crane and burst into flames Friday at a testing laboratory here, leaving one worker missing and presumed dead, injuring nine others and sending a mushroom-shaped cloud of smoke thousands of feet into the air, officials said.

Nearby test areas on this sprawling Mojave desert base were evacuated, a portion of a state highway was shut temporarily and Air Force firefighters and “disaster-response teams” battled for an hour to extinguish the blaze at the hilltop laboratory.

“It was a giant ball of fire with pure white smoke going up into a mushroom,” said Jack Tiger, a sales representative for a Palmdale company that supplies heavy equipment to the test site, a laboratory that has figured prominently in the development of the nation’s rocketry for decades.

The Titan 4, the largest unmanned space booster being developed by the Air Force, is designed to carry almost as much payload into orbit as the space shuttle and was intended to free the military from its dependency on the troubled shuttle program. But the Titan program, which costs $200 million per launch, is over budget and behind schedule and also has been plagued with malfunctions and other problems.

After the fire broke out, hospitals throughout the Antelope Valley were put on alert to prepare for patients from the base, but the casualty toll by late Friday held at nine injured, including one who suffered chemical burns and another whose elbow was fractured. Five workers were treated for smoke inhalation and released.

Names of the victims were not disclosed, but officials said three were believed to be civilian workers employed by an aerospace contractor.

One worker was still missing late Friday. Lt. Col. Jan Dalby said the base’s disaster response team was searching for him. But, he added, “We assume that he is dead.”

Some damage to surrounding buildings was also reported. The intense fire curled the metal siding on some structures, officials said.

The accident occurred at 10:45 a.m. as the rocket booster was being moved at the base’s Astronautics Laboratory. It forced several hundred employees to be evacuated from the facility, a 65-square-mile complex north of the base’s Test Flight Center and known as “The Rock.”

Mechanics said sections of the 112-foot rocket booster were being moved to an outdoor test stand where they would be further assembled. The procedure, called “stacking,” involves attaching the first and second stages to the bottom, largest section.

As the bottom section of one solid-fuel booster was being hoisted to the stand by a 900-ton crane, it became dislodged and fell 100 feet, igniting upon impact, Air Force Maj. Dick Cole said.

The piece that fell and caught on fire is the motor unit section of a Titan Advanced Solid Rocket booster, Air Force spokesmen said. Two such solid-fuel boosters are strapped to the sides of the middle section, or “core vehicle,” of a Titan 4 rocket and used to give the rocket initial liftoff. The liquid-fueled core vehicle, which carries the payload, then fires shortly after the boosters separate.

The segment that toppled from the crane was being tested to determine whether the Air Force wanted to purchase additional units, Cole said.

The crane, which stood more than 100 feet tall and could be seen for miles around, fell onto concrete blocks at the test stand. Air Force officials said the missing worker may be buried under the rubble, complicating recovery of the body.

“All I could see was that the crane fell over and a bunch of smoke went up,” said David Calta, a civil engineer who works at the Astronautics Laboratory. “(The crane) was like the landmark around here. It’s visible from quite a distance and now it’s not there anymore.”

Air Force officials emphasized the booster component did not explode but produced a sudden, large “flash fire.”

“It looked much like fireworks from the Fourth of July when you have a sparkler,” Ranney Adams, a spokesman for the Astronautics Laboratory, said.

There were conflicting accounts from witnesses, some of whom reported hearing a blast and others who did not.

“I heard a small boom and the next thing I know they were telling us to get out,” said a mechanic working at the base who spoke on condition of anonymity. “The security police said, ‘Ladies and gentlemen get off The Rock. Now!’ ”

The mechanic said there was a massive tie-up of cars leaving the base, and at least five ambulances passed him, going toward the lab.

Though the cloud of smoke, which billowed several thousand feet into the air, contained trace amounts of potentially toxic chemicals, such as hydrochloric acid, Air Force officials said it at no time posed a threat to surrounding communities in the sparsely populated desert area. It wafted northward, then dissipated, but could be seen up to 30 miles away.

No nuclear-delivery system was involved in the accident, officials said.

As the cloud drifted, the California Highway Patrol closed a 30-mile stretch of California 58 as a precaution. The road was opened about 40 minutes later.

“It looked like a thunderhead, a big plume of smoke curling into the air,” said a mechanic who works in a nearby laboratory. “Oh jeez, it was a half-mile in diameter. I have never seen anything like that.”

He added that workers were alerted to the emergency by an alarm system.

“I never heard any noise or explosion,” he said. “I was in another building. They came over the alert system saying, ‘We have a major emergency, all haz mat (hazardous material) and rescue teams go to your posts. This is not a drill. We have an emergency on hand.’ ”

Two inspectors from Cal/OSHA, the state job safety agency, arrived at the test site Friday afternoon. Officials from the Air Force Space Division, which oversees the Astronautics Laboratory, were also expected to join an investigation of the accident.

Sen. Pete Wilson (R-Calif.) also urged the Pentagon to investigate, saying the accident may have exposed “unknown deficiencies in Air Force procedures for moving, storing and installing” Titan 4 components.

Edwards, located in the western Mojave Desert about 100 miles north of Los Angeles, is home of the Air Force Flight Test Center, the country’s premier aerospace test and research facility. Nearly every aircraft in the Air Force inventory over the last 45 years has been tested and evaluated by the Air Force Flight Test Center, which is 17 miles south of the Astronautics Laboratory where Friday’s accident occurred.

The Astronautics Laboratory, the largest tenant at Edwards, represents the space and missile arm of the Air Force. With a 1989 budget of $137 million, it is charged with conducting advanced research and development involving space systems and rocket propulsion technologies, including solid propellant rocket motors.

The Titan 4 is the newest and largest unmanned space booster being developed by Air Force Systems Command’s Space Division. Built by the Martin Marietta Corp., it is designed to carry payloads equivalent in size and weight to those carried by the space shuttle.

Past Titan rockets have carried spy payloads. The first was launched on June 14, 1989, boosting what analysts said was either a missile-warning satellite or an electronic eavesdropping satellite. The second Titan 4, worth $173 million, was launched June 8 from Cape Canaveral, Fla., carrying a secret surveillance satellite into orbit.

Ten launches were planned during 1990-91, but six were postponed because of delays in preparing launch sites and taking delivery of the rockets. As of June, the Air Force said it planned two more Titan 4 launches this year.

The Pentagon also has said it plans to launch 10 Titan 4s annually by 1995.

The Air Force initially planned to build only 10 Titan 4s to complement the space shuttle as a way to launch heavy payloads. But the 1986 explosion that destroyed the shuttle Challenger and killed seven crew members prompted the Pentagon to decide to obtain many more.

Two Titan 34D rockets, the immediate predecessor to the Titan 4, failed during launch attempts at Vandenberg Air Force Base in 1985 and ’86. Also in 1986, a Titan 34D exploded at Vandenberg, injuring 58 people.

Times staff writers Glenn F. Bunting, Jack Cheevers, Michael Connelly, Marita Hernandez, Victor Merina, Alan C. Miller, Bob Pool, George Ramos and Jocelyn Stewart contributed to this story.

FACTS ABOUT THE TITAN $ ROCKET

A Titan 4 rocket booster fell and burned at a testing laboratory at Edwards Air Force Base. The accident occured at 10:45 a.m. on Friday as the rocket was being moved at the base’s Astronautics Laboratory. Dimensions: Consists of a two-stage, liquid-fueled rocket that is about 200 feet tall, plus 112-foot-tall, stap-on, solid-fueled booster rockets. The boosters are 10 feet in diameter and weigh 771,000 pounds each. Launch cost: Approximately $200 million. Payload: Can lift a 39,000-pound cargo into low Earth orbit or a 10,000-pound payload to a fixed orbit 22,300 miles high. By comparison, the space shuttle can put a 52,000-pound payload into orbit. Contractor: Martin Marietta was awarded the $7.3-billion Air Force contract to build 41 Titan 4s. Engines: Two solid-propellant rockets (boosters) made by Martin Marietta. Two liqid-fueled main engines plus an upper stage Centaur rocket, made by General Dynamics. Fuel: Hydrazine and nitrogen tetroxide propellants for the solid rocket boosters and liquid oxygen/hydrogen for the liquid rockets. Launch sites: There are four Titan pads, two at Vandenberg Air Force Base and two in Cape Canaveral in Florida. Potential launch capability: Up to 20 per year. Compiled by editorial researcher Michael Meyers