Launch of giant rocket in Southern California heard for miles

With a thunderous roar heard for miles around, the tallest rocket ever launched from Vandenberg Air Force Base blasted into outer space, hurtling over the Pacific Ocean as it cut across the afternoon sky.

At 1:10 p.m. Pacific time, the 23-story Delta IV Heavy rocket lifted off from the base northwest of Santa Barbara. A white plume trailed the massive rocket as it ascended.

Standing 235 feet tall, the rocket was so large that the blast reportedly was heard as far away as 50 miles. According to aerospace experts, the booster was carrying a top-secret spy satellite for the National Reconnaissance Office — the covert federal umbrella agency that operates spy satellites.

The rocket hit speeds of about 17,500 mph as it climbed toward space. About six minutes after launch, the first stage of the rocket broke away — later splashing down in the Pacific.

Because the rocket was so large, it was visible from much of the Southland after its launch, but it was difficult to see because the launch was in the middle of the day.

“Someone not looking for the launch probably wouldn’t have noticed it,” said Brian Webb of Thousand Oaks, who runs the website SpaceArchive.info, which monitors rocket launches.

Standing with binoculars on a bluff overlooking Highway 101 about three miles east of Santa Barbara, Webb said moments afterward that he could see “two or three very closely spaced orange points of light.”

“Below me, vehicles were pulling off and stopping on the southbound shoulder of Highway 101 before the launch,” he said. “Some of them were outside of their vehicle or vehicles.”

The rocket lifted off from the base’s Space Launch Complex 6, known on base as “Slick Six.” The launch pad was built in the 1960s.

The Delta IV Heavy was built by United Launch Alliance, a joint venture of Lockheed Martin Corp. and Boeing Co. The rocket’s three massive engines were built by Pratt & Whitney Rocketdyne in Canoga Park.

william.hennigan@latimes.com