A Falcon 9 rocket missing its payload fired its nine Merlin 1D main engines at 8:30 p.m. EDT Thursday (0030 GMT Friday). Credit: SpaceX

Six days after SpaceX fired its last Falcon 9 rocket from NASAs Kennedy Space Center, another launcher rolled to historic pad 39A and ignited its nine Merlin 1D engines at sunset Thursday in preparation for a commercial satellite delivery mission Sunday for Intelsat.

The two-stage rocket rolled out to pad 39A from SpaceXs nearby hangar Thursday, and ground teams lifted it vertical on the pads launch mount around 1 p.m. EDT (1700 GMT). A few hours later, SpaceXs launch crew loaded super-chilled, densified RP-1 kerosene and liquid oxygen propellants into the rocket.

The nine Merlin 1D engines affixed to the base of the first stage ignited at 8:30 p.m. EDT Thursday (0030 GMT Friday), a few minutes after sunset at Cape Canaveral. The engines ramped up to full throttle around 1.7 million pounds of thrust and fired for around seven seconds, sending a plume of exhaust into the air and a dull rumble across the Florida spaceport.

SpaceX confirmed the test on Twitter a few minutes later, and the hotfire keeps the companys next mission on track for liftoff Sunday at 7:36 p.m. EDT (2336 GMT), weather permitting.

Engineers will review data from Thursday nights test before clearing the Falcon 9 rocket for flight in a launch readiness review.

The flight will loft the Intelsat 35e communications satellite on a trip toward geostationary orbit, a perch nearly 22,300 miles (35,800 kilometers) over the equator. Built by Boeing, the Intelsat 35e spacecraft is set for a 15-year service life covering the Americas, the Caribbean, the Atlantic Ocean, Europe and Africa for Intelsat.

SpaceXs technicians will remove the Falcon 9 rocket from pad 39A as soon as Friday and roll it back to the hangar a quarter-mile away, where workers will connect the Intelsat 35e satellite and its protective payload fairing to the two-stage launcher.

The U.S. Air Force weather team predicts iffy conditions could prevent the Falcon 9 from launching Sunday. Anvil clouds and cumulus clouds from storms expected across Central Florida have a 60 percent chance of violating weather criteria for a launch, forecasters said.

If the Falcon 9 is able to blast off Sunday, it will be the third launch by SpaceX in less than 10 days.

A Falcon 9 rocket took off June 23 from Kennedy Space Center with the BulgariaSat 1 communications satellite, then another Falcon 9 launched June 25 from Vandenberg Air Force Base in California with 10 voice and data relay spacecraft for Iridium. Both missions were successful and featured landings of the Falcon 9s first stage on platforms at sea.

BulgariaSat 1s booster made its second flight after SpaceX recovered, inspected and refurbished the stage following its first liftoff in January.

SpaceX does not plan to recover the first stage after Intelsat 35es launch due to the satellites heavy weight. The booster is not fitted with the landing legs or grid fins needed for a landing.

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Next SpaceX launch on track for Sunday after hold-down firing at pad 39A - Spaceflight Now