SpaceX rocket explodes on launch pad during simulated countdown

CAPE CANAVERAL, Fla. - A SpaceX Falcon 9 rocket exploded on its Florida launch pad today during a dress rehearsal for a satellite launch, which had been scheduled for this weekend.

Thick black smoke and flames could be seen billowing from Launch Complex 40 at Cape Canaveral Air Force Station earlier this morning.  Social media users in the area reported hearing and feeling several consecutive blasts from the direction of the pad just after 9 a.m.

There was no word of any injuries, according to a statement released by SpaceX.

It's common for launch providers like SpaceX to simulate a full countdown in the days leading up to each launch, a test known as a wet dress rehearsal because the tanks are actually filled with fuel, then drained. SpaceX is unique, though, in their procedure to finish the rehearsal with a brief test-firing of the engines.  

The rocket was scheduled to launch the AMOS-6 communications satellite at 3 a.m. Saturday on behalf of a group that includes social network company Facebook.  The Israeli-built satellite would have provided internet access to under-developed nations in Africa.

The Falcon 9 rocket had suffered only one other significant failure, an in-flight breakup that was later blamed on a tank over-pressurization.  The rocket has made nine successful launches and even some first-stage landings since that accident.

SpaceX was planning to use the Falcon 9 to begin flying astronauts to the space station as soon as next year.  It was not immediately clear what effect today's explosion would have on the timeline for those plans, though any damage to the launch pad would likely delay the company's next few commercial launches.