December 13, 2019

Launch timeline for Falcon Heavy’s second flight


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EDITOR’S NOTE: Updated after SpaceX scrubbed Wednesday’s launch attempt.

SpaceX’s second Falcon Heavy rocket is set for liftoff Thursday from NASA’s Kennedy Space Center in Florida, and the heavy-lift launcher will head on an easterly course over the Atlantic Ocean atop more than 5 million pounds of thrust.

The 229-foot-tall (70-meter) rocket is poised for launch from pad 39A at NASA’s Kennedy Space Center in Florida during a launch window Thursday that opens at 6:35 p.m. EDT (2235 GMT) and closes at 8:31 p.m. EDT (0031 GMT).

The payload mounted atop the Falcon Heavy rocket is Arabsat 6A, a communications satellite built by Lockheed Martin for Arabsat, an operator based in Saudi Arabia.

Read our Mission Status Center for live coverage of the countdown and launch.

Credit: SpaceX

The graphic above illustrates the paths of the Falcon Heavy’s two side boosters, center core stage, and second stage during the rocket’s launch and landing operations. Four different components of the Falcon Heavy will follow trajectories toward different landing zones, or toward Earth orbit.

The timeline below outlines the launch sequence for the Falcon Heavy’s second mission — and first commercial flight.

Data source: SpaceX

T-0:00:00: Liftoff

The Falcon Heavy’s engine controllers will command nine Merlin 1D engines on each of the rocket’s three first stage boosters to ignite at T-minus 2 seconds. Hold-down clamps will open to release the Falcon Heavy from launch pad 39A as the countdown clock reaches zero, once the vehicle passes an automated health check.

T+0:01:09: Max Q

The Falcon Heavy rocket reaches Max Q, the point of maximum aerodynamic pressure.

T+0:02:30: BECO

The Merlin 1D engines on the two side boosters shut down a few seconds before booster separation.

T+0:02:34: Booster Separation

The two 15-story-tall side boosters separate from the Falcon Heavy rocket to begin their descent back to Cape Canaveral.

T+0:02:51: Side Cores Begin Boostback Burn

After flipping around to fly tail-first, the Falcon Heavy’s two side boosters each reignite three of their engines to begin their return to Cape Canaveral for landing.

T+0:03:31: MECO

The Falcon 9’s nine Merlin 1D engines shut down.
The Falcon Heavy’s nine core stage Merlin 1D engines shut down.

T+0:03:35: Stage Separation

The Falcon Heavy’s center core stage separates from the second stage moments after MECO.

T+0:03:42: First Ignition of Second Stage

The second stage Merlin 1D vacuum engine ignites for a five-minute burn to put the rocket and its payload into a preliminary parking orbit.

T+0:04:07: Fairing Jettison

The 5.2-meter (17.1-foot) diameter payload fairing jettisons once the Falcon Heavy rocket ascends through the dense lower atmosphere. The 43-foot-tall fairing is made of two clamshell-like halves composed of carbon fiber with an aluminum honeycomb core

T+0:06:11: Side Boosters Begin Entry Burn

The Falcon Heavy’s two side boosters reignite a subset of their Merlin engines for an entry burn prior to touchdown.

T+0:07:00: Center Core Begins Entry Burn

The Falcon Heavy’s center core stage begins its entry burn targeting SpaceX’s drone ship “Of Course I Still Love You” in the Atlantic Ocean.

T+0:07:51: Side Booster Landings

The Falcon Heavy’s two side boosters touch down at Landing Zone 1 and Landing Zone 2 at Cape Canaveral Air Force Station.

T+0:08:48: SECO 1

The second stage of the Falcon Heavy rocket shuts down after reaching a preliminary low-altitude orbit. The upper stage and and its payload — the Arabsat 6A communications satellite — begin a coast phase scheduled to nearly 19 minutes before the second stage Merlin vacuum engine reignites.

T+0:09:48: Center Core Landing

The Falcon Heavy’s central core stage touches down on “Of Course I Still Love You,” SpaceX’s drone ship positioned a few hundred miles east of Cape Canaveral in the Atlantic Ocean.

T+0:27:34: Second Ignition of Second Stage

The Falcon 9's second stage Merlin engine restarts to propel the SES 9 communications satellite into a supersynchronous transfer orbit.
The Falcon Heavy’s second stage Merlin engine restarts to head into a higher orbit around Earth.

T+0:29:00: SECO 2

The Merlin engine shuts down after a short burn to put the SES 10 satellite in the proper orbit for deployment.
The Merlin engine shuts down after a short burn to inject the Arabsat 6A communications satellite into a supersynchronous transfer orbit ranging between 124 miles (200 kilometers) and 55,923 miles (90,000 kilometers) in altitude, with an inclination of 23 degrees to the equator.

T+0:34:02: Arabsat 6A Separation

The SES 9 satellite separates from the Falcon 9 rocket in an orbit with a predicted high point of about 39,300 kilometers (24,400 miles), a low point of 290 kilometers (180 miles) and an inclination of 28 degrees. Due to the decision to burn the second stage nearly to depletion, there is some slight uncertainty on the orbital parameters based on the exact performance of the launcher.
The 14,252-pound (6,465-kilogram) Arabsat 6A communications satellite separates from the Falcon Heavy rocket into an elliptical supersynchronous transfer orbit, on the way to a perch in geostationary orbit.

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Follow Stephen Clark on Twitter: @StephenClark1.


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