Video: SpaceX rocket explodes at Cape

CAPE CANAVERAL, Fla. – A SpaceX Falcon 9 rocket exploded on its pad during a test Thursday morning at Cape Canaveral Air Force Station. No one was injured.

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Witnesses reported seeing a fireball, hearing multiple explosions, feeling shock waves in buildings several miles away at Kennedy Space Center and seeing a plume of smoke rising from Launch Complex 40 just after 9 a.m.

SpaceX CEO Elon Musk said around 1 p.m. that a failure occurred while the rocket was being fueled for a test-firing of its main engines, part of preparations for a planned early Saturday launch of a commercial communications satellite in which Facebook had a stake.

"Originated around upper stage oxygen tank," Musk said on Twitter. "Cause still unknown. More soon."

Earlier, SpaceX confirmed that the Amos-6 communications satellite owned by Spacecom, an Israeli company, also was destroyed.

Facebook had planned to use some of the satellite's capacity to expand its Internet.org initiative in Africa. CEO Mark Zuckerberg was in Africa promoting the satellite's benefits ahead of the upcoming launch.

"I'm deeply disappointed to hear that SpaceX's launch failure destroyed our satellite that would have provided connectivity to so many entrepreneurs and everyone else across the continent," said Facebook CEO Mark Zuckerberg, who was in Africa promoting the satellite's benefits, in a post on his Facebook page. "We remain committed to our mission of connecting everyone, and we will keep working until everyone has the opportunities this satellite would have provided."

Facebook had partnered with French company Eutelsat, which also planned to use the Amos-6 satellite to expand broadband Internet access in sub-Saharan Africa.

The so-called "static fire" test is a standard pre-launch milestone that SpaceX performs. It serves as a countdown rehearsal that fuels the rocket and is intended to culminate in a brief firing of the rocket's nine Merlin main engines, while the rocket remains held down on the pad.

The pad at Launch Complex 40 was cleared of personnel for the hazardous operation.

The accident comes just over a year after SpaceX suffered its only in-flight failure by a Falcon 9, about two minutes into a launch of International Space Station supplies for NASA.

That failure was attributed to a broken strut that caused the upper-stage oxidizer tank to rupture, resulting in the rocket breaking apart.

SpaceX returned the Falcon 9 to flight six months later, and had completed nine successful launches since December, including eight by an upgraded, more powerful version of the rocket.

The company has made headlines during that period for landing six Falcon boosters, part of Musk's effort to develop reusable rockets.

While the cause of the latest mishap is unknown, it almost certainly will result in months of delays to a SpaceX launch schedule that was already behind, causing consternation among its backlogged customers.

In addition to an investigation into any problems with the rocket, it was not immediately clear if the launch pad suffered significant damage.

The Volusia County Sheriff's Office said it received several 911 calls to report the explosion heard from as far as Edgewater.

"I'm down here in Edgewater and we heard a huge, loud ... um, noise that was almost like what you would heard when a shuttle would goes over," the caller told dispatchers. "I mean it was like a loud noise ... and then I saw these emergency vehicles go by ... do you know what's going on?" 

Video courtesy of Michael Folds showed the smoke pluming into the air across the waterway from the launch pad.

The accident also came a year before SpaceX hoped to launch a first test flight with astronauts to the International Space Station as part of NASA's Commercial Crew Program.

Boeing is competing with SpaceX to fly the first crew. Boeing plans to fly its CST-100 Starliner capsule on United Launch Alliance's Atlas V rocket, which has not suffered a major failure in more than 60 missions.

Brevard County Emergency Management Director Kimberly Prosser said Thursday morning that the incident posed “no hazards to the general public.”

“We’re monitoring the situation, but there have been no requests for assistance,” she said.

KSC's Emergency Operations Center personnel were monitoring the situation and standing by to assist if required, while the environmental health office monitored air quality to ensure it is safe for employees, said spokesman Mike Curie.

In a statement, U.S. Sen. Bill Nelson said the accident was a reminder that spaceflight is risky.

“As we continue to push the frontiers of space, there will be both triumphs and setbacks," he said. "But at the end of the day, I’m confident that our commercial space industry will be very successful.”

SpaceX's eight successful launches so far in 2016 were its most yet in any calendar year, and the company had hoped to complete at least as many more before the end of the year. The upcoming missions potentially included the debut of a heavy-lift Falcon rocket from a different launch pad at Kennedy Space Center.

At the Titusville Area Chamber of Commerce the explosion startled the staff.

“We were sitting here and all of a sudden it sounded like a sonic boom and the building started to shake,” said Denny Waktins of the chamber. “There were a couple of minor booms after that and then we went outside and saw the smoke plume. It was a well-defined plume, not like a controlled burn.”

An administrator at Titusville High School, just across the Indian River from Cape Canaveral Air Force Station, said those at the school felt the effects of the explosion, but it was pretty similar to what they experience during a launch.