Spectators who gathered across the Central Coast to watch the launch of Firefly Aerospace's Alpha rocket — a privately designed, unmanned rocket built to carry satellites — instead saw it explode midair and debris rain down on nearby areas.

"I saw this thing floating down from the sky ... then another piece, then another, and then hundreds of pieces varying in size were falling," said Mike Hecker, a resident of Solvang who was out mountain biking in the Orcutt Hills with a large group of friends.

"It was surreal to have rocket debris raining down on you," he said.

After a successful liftoff at 6:59 p.m. Sept. 2 from Space Launch Complex-2 at Vandenberg Space Force Base, the ascending Alpha rocket exploded over the Pacific Ocean two minutes and 30 seconds after takeoff when Space Launch Delta 30 terminated its flight, according to Vandenberg Space Force Base range operations.

The explosion, which could be seen for more than 100 miles in the clear evening sky, left a large cloud of smoke and visible debris falling back to Earth.

"I quickly registered that it was debris from the rocket," recalled Hecker, who had separated from his group to ride out of the hills only to find himself in the path of falling wreckage. 

"Some fell as close as 50 feet from me," he said, noting that he quickly sought shelter under a nearby tree to avoid being hit — some pieces were as large as a Volkswagen bug.

Shortly after the incident, Firefly Aerospace Inc., based in Austin, Texas, announced via Twitter that the vehicle had been lost due to an "anomaly" during first stage ascent.

The company also alerted the public to possible debris in the area as a result of the explosion and asked locals to keep at least 50 feet away from pieces of wreckage, which investigators said should be considered unsafe.

Hecker said he has reported the debris he found to Firefly, but before the company's alert, admitted to inspecting the pieces up close.

"It wasn't steaming or glowing," he said, "so I touched it. It's carbon fiber."

Lompoc resident Frank Barna, who witnessed the launch from his front yard with his wife, Becky Barna, said he was at first "confused" by what he saw.

"I knew it wasn't right when I saw the big explosion," he said. "I didn't believe what I saw. But I thought maybe that's how their stages separate."

Barna, who retired last year from nearly 50 years "in the missile business" between the U.S. Air Force and as a contractor with NASA, said it was the first time he had seen such a sight.

Sign up to receive headlines in your inbox!

Breaking News | Local Sports | Daily Headlines | Local Obituaries | Weather | Local Offers

"I've seen a lot of them get aborted while on the pad, but it was the first time I've seen one destroyed in midair," he said.

In reviewing videos online, Barna said he suspects that range operations lost control of the rocket when it began tumbling, forcing the mission to be aborted for safety reasons.

Barna said from what he understands, such an outcome is typical for aerospace companies conducting their first test launch.

"So, it's kind of expected," he said. "I feel bad that it happened, but it was also pretty awesome to watch."

According to Vandenberg Space Force Base officials, no injuries associated with the explosion have been reported and a team of investigators is working to determine the cause of the failure.

090221 Firefly explodes

Firefly Aerospace's Alpha rocket explodes minutes after launch from Vandenberg Space Force Base on Thursday evening.

On Sept. 3, Firefly Aerospace released a statement assuring the public that information gathered from the incident would be applied to future missions as they continue to develop various launch and space vehicles, including a lunar lander.

“While we did not meet all of our mission objectives, we did achieve a number of them: successful first stage ignition, liftoff of the pad, progression to supersonic speed, and we obtained a substantial amount of flight data," Firefly's statement read. 

The rocket was carrying a payload dubbed "DREAM," or the Dedicated Research and Education Accelerator Mission, which consisted of items from schools and other institutions, including small satellites and several demonstration spacecraft.

The Firefly Alpha is designed to become the company's first two-stage rocket — carrying up to 2,200 pounds (1,000 kilograms) of payload — that launches small satellites into Earth orbit twice a month.

Launches would have a starting price of $15 million, according to Firefly.

Lisa André covers lifestyles and local news for Santa Ynez Valley News and Lompoc Record. The Associated Press contributed to this report.