May 24, 2018

Falcon 9 launch timeline with GovSat 1

SpaceX’s Falcon 9 rocket is set for liftoff from Cape Canaveral on Tuesday, heading due east over the Atlantic Ocean to deliver the GovSat 1 communications satellite into orbit around 32 minutes later.

The 229-foot-tall (70-meter) rocket is poised for launch from pad 40 at Cape Canaveral Air Force Station in Florida at 4:25 p.m. EST (2125 GMT) Tuesday at the opening of a 141-minute launch window.

Perched atop the rocket is the GovSat 1 communications satellite, a spacecraft manufactured by Orbital ATK for a public-private joint venture named LuxGovSat founded by SES and the government of Luxembourg. GovSat 1’s military-grade X-band and Ka-band communications payload will support defense and security missions by Luxembourg and its NATO allies across Europe, Africa, the Middle East and adjacent waters.

The Falcon 9 rocket will fly with a reused first stage booster recovered after a launch May 1, 2017, with the National Reconnaissance Office’s classified NROL-76 payload. SpaceX does not plan to recover the Falcon 9’s first stage on the GovSat 1 mission.

The timeline below outlines the launch sequence for the Falcon 9 flight with GovSat 1.

Data source: SpaceX

T-0:00:00: Liftoff

After the rocket’s nine Merlin engines pass an automated health check, hold-down clamps will release the Falcon 9 booster for liftoff from Complex 40.
After the rocket’s nine Merlin engines pass an automated health check, hold-down clamps will release the Falcon 9 booster for liftoff from pad 40.

T+0:01:10: Mach 1

The Falcon 9 rocket reaches Mach 1, the speed of sound.
The Falcon 9 rocket reaches Mach 1, the speed of sound, as the nine Merlin 1D engines provide more than 1.7 million pounds of thrust.

T+0:01:18: Max Q

The Falcon 9 rocket reaches Max Q, the point of maximum aerodynamic pressure.
The Falcon 9 rocket reaches Max Q, the point of maximum aerodynamic pressure.

T+0:02:38: MECO

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

T+0:02:40: Stage 1 Separation

The Falcon 9’s first stage separates from the second stage moments after MECO.
The Falcon 9’s first stage separates from the second stage moments after MECO.

T+0:02:41: First Ignition of Second Stage

The second stage Merlin 1D vacuum engine ignites for an approximately 6-minute burn to put the rocket and SES 9 into a preliminary parking orbit.
The second stage Merlin 1D vacuum engine ignites for a six-minute burn to put the rocket and GovSat 1 into a preliminary parking orbit.

T+0:03:44: Fairing Jettison

The 5.2-meter (17.1-foot) diameter payload fairing jettisons once the Falcon 9 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.
The 5.2-meter (17.1-foot) diameter payload fairing jettisons once the Falcon 9 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+0:08:35: SECO 1

The second stage of the Falcon 9 rocket shuts down after reaching a preliminary low-altitude orbit. The upper stage and SES 9 begin a coast phase scheduled to last more than 18 minutes before the second stage Merlin vacuum engine reignites.
The second stage of the Falcon 9 rocket shuts down after reaching a preliminary low-altitude orbit. The upper stage and GovSat 1 begin a coast phase scheduled to last more than 18 minutes before the second stage Merlin vacuum engine reignites.

T+0:26:40: 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 9’s second stage Merlin engine restarts to propel the GovSat 1 communications satellite into a supersynchronous transfer orbit.

T+0:27:48: 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 put the GovSat 1 satellite in the proper orbit for deployment.

T+0:32:19: GovSat 1 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 GovSat 1 satellite separates from the Falcon 9 rocket in a supersynchronous transfer orbit.

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