SpaceX targeting Friday for Falcon Heavy test fire at KSC

Update: See live updates of Falcon Heavy's status here.

Update, 11 a.m. Wednesday:

SpaceX is now targeting no earlier than 3:30 p.m. Friday for a test fire of its Falcon Heavy rocket at Kennedy Space Center. Teams have six hours, or until 9:30 p.m., to briefly fire the 27 Merlin engines.

Original story:

SpaceX teams at Kennedy Space Center fueled the company's highly anticipated Falcon Heavy rocket Thursday, paving the way for a brief test fire of its 27 engines as soon as Friday. 

Thursday's test was scheduled during a six-hour window that opened at 1 p.m., but was delayed due to unspecified reasons. Vapors were visible around the rocket and pad 39A just before the window opening, indicating that the 230-foot-tall rocket had at least been fueled for the first time.

SpaceX will target 10 a.m. to 6 p.m. for the next test fire attempt on Friday.

When Falcon Heavy does finally fire its 27 Merlin engines for about 12 seconds, teams will analyze results from the operation before the rocket's first-ever flight around the end of January, according to CEO Elon Musk. 

[Launch schedule: Upcoming Florida rocket launches and landings]

[SpaceX denies Falcon rocket caused Zuma mission failure]

Falcon Heavy will officially become the most powerful operational rocket in the world when it lifts off from the historic pad with more than 5.1 million pounds of thrust.

And if the test fire and demonstration flight are successful, SpaceX's manifest will open up to new capabilities thanks to its ability to take heavier payloads to orbit. The company has signed at least two contracts – with Inmarsat and Arabsat – to launch payloads on the Heavy.

At neighboring Cape Canaveral Air Force Station, meanwhile, a military missile warning satellite was hoisted atop a United Launch Alliance Atlas V rocket ahead of a planned liftoff next Thursday. The spacecraft, part of Air Force's Space Based Infrared System, or SBIRS, is scheduled to vault off the pad at Launch Complex 41 at 7:52 p.m.

Contact Emre Kelly at aekelly@floridatoday.com or 321-242-3715. Follow him on Twitter and Facebook at @EmreKelly.

By the numbers: Falcon Heavy

• Height: 230 feet
• Width: 40 feet
• Cores: Three Falcon
• Engines: 27 Merlin
• Thrust: More than 5 million pounds at liftoff
• Payload to low Earth orbit: 140,000 pounds
• Landing Legs: Installed on all three cores