SpaceX’s Falcon 9 rocket is set for liftoff from Cape Canaveral early Thursday, heading due east over the Atlantic Ocean to deliver the Inmarsat 5 F4 communications satellite into orbit 32 minutes later.
The 229-foot-tall (70-meter) rocket is poised for launch from pad 39A at NASA’s Kennedy Space Center in Florida at 7:21 p.m. EDT (2321 GMT) Thursday at the opening of a 49-minute launch window.
Perched atop the rocket is the Inmarsat 5 F4 communications satellite, a spacecraft made by Boeing, ready to join Inmarsat’s Global Xpress network providing broadband connectivity to airline passengers and maritime crews. The rocket will place the satellite into a high-altitude “supersynchronous” transfer orbit.
The timeline below outlines the launch sequence for the Falcon 9 flight with Inmarsat 5 F4. On this mission, SpaceX does not plan to attempt a recovery of the rocket’s first stage booster due to the high performance required to place the heavy Inmarsat 5 F4 spacecraft into a high-altitude orbit.
The Falcon 9 does not carry landing legs or grid fins, which are not required for the expendable mission.
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 pad 39A.
T+0:01:13: Mach 1
The Falcon 9 rocket reaches Mach 1, the speed of sound, as the nine Merlin 1D engines provide more than 1.5 million pounds of thrust.
T+0:01:17: Max Q
The Falcon 9 rocket reaches Max Q, the point of maximum aerodynamic pressure.
T+0:02:45: MECO
The Falcon 9’s nine Merlin 1D engines shut down.
T+0:02:49: Stage 1 Separation
The Falcon 9’s first stage separates from the second stage moments after MECO.
T+0:02:56: First Ignition of Second Stage
The second stage Merlin 1D vacuum engine ignites for a nearly 6-minute burn to put the rocket and Inmarsat 5 F4 into a preliminary parking orbit.
T+0:03:35: 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.
T+0:08:38: SECO 1
The second stage of the Falcon 9 rocket shuts down after reaching a preliminary low-altitude orbit. The upper stage and Inmarsat 5 F4 begin a coast phase scheduled to last more than 18 minutes before the second stage Merlin vacuum engine reignites.
T+0:26:59: Second Ignition of Second Stage
The Falcon 9’s second stage Merlin engine restarts to propel the Inmarsat 5 F4 communications satellite into a supersynchronous transfer orbit.
T+0:27:55: SECO 2
The Merlin engine shuts down after a short burn to put the Inmarsat 5 F4 satellite in the proper orbit for deployment.
T+0:31:48: Inmarsat 5 F4 Separation
The Inmarsat 5 F4 satellite separates from the Falcon 9 rocket in a supersynchronous transfer orbit. Due to a 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.
SpaceX’s Falcon 9 rocket lifted off Wednesday at 10:29 a.m. EDT (1429 GMT), launching with two Boeing-built communications satellites for Eutelsat and Asia Broadcast Satellite.
A Minotaur 4 rocket made up of five solid-fueled rocket motors delivered a U.S. military satellite tracking craft into an equatorial orbit early Saturday after lifting off from Cape Canaveral.
Arianespace’s third Ariane 5 launch of the year was set liftoff Friday from Kourou, French Guiana, but an issue with a sensor on the rocket’s first stage liquid hydrogen tank caused officials to scrub the launch attempt. The Ariane 5 is poised to carry three U.S.-built commercial satellites into orbit, while testing a few rocket upgrades, including a modified fairing needed for the launch of the James Webb Space Telescope next year.
