The 229-foot-tall Falcon 9 rocket, according to one source, was not the one that is supposed to carry the SES-10 satellite into orbit later this year.
But eyewitnesses on Twitter are reporting the test ended in calamity on a launch pad in Cape Canaveral, Florida: with a huge explosion sometime after 9 a.m. EDT on Thursday, Sept. 1, 2016.
Rocket engineer Ian Dawson has shared one of the closest views of the launch pad so far, which clearly shows a core of flames beneath a tower of billowing smoke:
I hope everyone is OK at #SpaceX. pic.twitter.com/HFN5jiGDDf
- Ian Dawson (@PointyEndUp) September 1, 2016
Scott Gustin, the national content editor for Tribune Broadcasting, also had a crisp view of the huge launch pad blaze:
Wow. Photo shows one of the explosions at #SpaceX: https://t.co/xZvJk9tc1i (Reddit/mtrevor123) pic.twitter.com/bzsy9ATvIy
- Scott Gustin (@ScottGustin) September 1, 2016
One eyewitness reported the blast shook his office building:
Wow, SpaceX rocket just blew up on pad. Shook our whole bldg. pic.twitter.com/PMxZA4v4IV
- SpaceCoastTiger (@TigernBear) September 1, 2016
@murphypak @SpaceX @NASASpaceflight @CwG_NSF felt it at work too...static fire was scheduled...
- Julia Bergeron (@julia_bergeron) September 1, 2016
Harvard astronomer Jonathan McDowell alleges the rocket test was not the rocket that SpaceX plans to reuse for its upcoming launch of SES-10:
Note that the Falcon 9 that just exploded was NOT the reused one - that was scheduled for next month, but of course will be delayed now
- Jonathan McDowell (@planet4589) September 1, 2016
Users are starting to post video of the flames and smoke:
Just got this from KSC @WFTV pic.twitter.com/vK2FfLdrIC
- Martha Sugalski (@MarthaSugalski) September 1, 2016
The smoke is so thick that it's showing up on local weather radar:
Significant smoke plume coming from the Cape Canaveral Space X launch pad in Florida, seen on radar. #Spacex pic.twitter.com/43FiZKMIXB
- Brad Panovich (@wxbrad) September 1, 2016
Wow. You can see the smoke from the #SpaceX explosion in Cape Canaveral on radar. pic.twitter.com/IWqL7IGpU4
- Jesse Hawila (@JesseHawilaKCTV) September 1, 2016
Business Insider spoke with a representative at NASA's Kennedy Space Center in Cape Canaveral, but she did not have any details about the explosion.
We also contacted SpaceX for details about the blast, but representatives for the aerospace company did not immediately respond.
It's unknown at this time if anyone was hurt by the incident.
Keep checking this page; we'll update it as soon as we learn more.
Lauren Friedman and Rebecca Harrington contributed to this post.