The explosion occurred at 9:07 a.m. EDT (1307 GMT), as SpaceX was preparing to launch the Amos-6 communications satellite for the Israeli company Spacecom from a pad at the Cape Canaveral Air Force Station on Saturday, Sept. 3. At the time, SpaceX was conducting a static-fire engine test on the Falcon 9. Such tests, which typically precede each SpaceX launch, involve firing the Falcon 9 rocket's first-stage engines while the booster remains secured to the launchpad.
"SpaceX can confirm that in preparation for today's static fire, there was an anomaly on the pad resulting in the loss of the vehicle and its payload," SpaceX representatives wrote in a statement. "Per standard procedure, the pad was clear, and there were no injuries." [SpaceX's Falcon 9 Rocket Explained]
UPDATE: USLaunchReport has released video of the explosion on its YouTube page:
The Amos-6 communications satellite reportedly cost $195 million and was built for Spacecom by Israel Aerospace Industries to serve as a replacement for Spacecom's Amos-2 satellite, which is expected end its mission this year. In October 2015, Facebook and the satellite communications company Eutelsat also announced a $95 million agreement to lease broadband capacity on the satellite from Spacecom, according to SpaceNews.
NASA webcam images of the SpaceX rocket's launch site — Space Launch Complex 40 — at the Cape Canaveral Air Force Station showed a massive plume of black smoke over the pad Thursday morning.
US EVA37: Twitter user Ian Dawson posts this shot: pic.twitter.com/s28GCs10V3— William Harwood (@cbs_spacenews) September 1, 2016
NASA says SpaceX was conducting a test firing of its unmanned rocket when the blast occurred Thursday morning. pic.twitter.com/Bc7kNiq6E0— WESH 2 News (@WESH) September 1, 2016
The Falcon 9 rocket is a two-stage booster designed to launch satellites and SpaceX's Dragon space capsules into orbit. The rocket stands 229 feet tall (70 meters) and uses rocket-grade kerosene and liquid oxygen for propellant.
The first stage of Falcon 9 is powered by nine Merlin rocket engines, while the second stage has a single engine to make the final push into orbit with payloads. It is the first stage of Falcon 9 that SpaceX would have been testing during Thursday's static fire operation.
SpaceX has had a long string of successful missions with the Falcon 9 rocket, with only one major failure. In June 2015, a Falcon 9 carrying a Dragon cargo ship for NASA exploded shortly after liftoff. SpaceX traced the problem to a faulty strut, and made upgrades before resuming commercial and NASA flights.
Editor's note: This story, originally posted at 9:38 a.m. EDT, was updated to include details from SpaceX's official statement on the explosion, which cited a pad anomaly, not the Falcon 9 rocket itself. It was also updated to correct the launch month of SpaceX's Falcon 9 failure to June 2015. An 11:46 a.m. EDT update pinned down the time of the pad explosion as announced by officials with the Cape Canaveral Air Force Station.