SpaceX’s third Falcon Heavy rocket is set for liftoff 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 four launch window that opens at 11:30 p.m. EDT Monday (0230 GMT Tuesday) and closes at 3:30 a.m. EDT (0730 GMT).
There are two dozen satellites mounted on top of the rocket awaiting launch into three distinct orbits, which are described in the timeline below.
Mission Status Center for live coverage of the countdown and launch.
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 third mission, and the first Falcon Heavy flight for the U.S. Air Force.
Data source: SpaceX
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+0:00:42: Max Q
The Falcon Heavy rocket reaches Max Q, the point of maximum aerodynamic pressure.
The Merlin 1D engines on the two side boosters shut down a few seconds before booster separation.
T+0:02:31: Booster Separation
The two 15-story-tall side boosters separate from the Falcon Heavy rocket to begin their descent back to Cape Canaveral.
T+0:02:49: 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.
The Falcon Heavy’s nine core stage Merlin 1D engines shut down.
T+0:03:31: Stage Separation
The Falcon Heavy’s center core stage separates from the second stage moments after MECO.
T+0:03:38: 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+0:04:03: 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+0:07:13: 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+0:08:38: SECO 1
The second stage of the Falcon Heavy rocket shuts down after reaching the first of three target orbits on the STP-2 mission, with a perigee, or low point, of 186 miles (300 kilometers) an apogee, or high point, of 534 miles (860 kilometers), and an inclination of 28.5 degrees.
T+0:08:41: 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+0:08:53: 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+0:11:21: Center Core Landing
The Falcon Heavy’s central core stage touches down on “Of Course I Still Love You,” SpaceX’s drone ship positioned nearly 770 miles (1,240 kilometers) east of Cape Canaveral in the Atlantic Ocean.
T+0:12:55: Spacecraft Deployments Begin
The first sequence of satellite separations begins. The Oculus-ASR microsatellite, along with 12 CubeSats, will be deployed in the first orbit on the STP-2 mission.
T+1:12:39: Second Stage Engine Restart
The Falcon Heavy’s second stage Merlin engine restarts to change orbits for the next phase of the mission.
T+1:13:00: SECO 2
The Merlin engine shuts down after a short burn to reach a circular 447-mile-high (820-kilometer) orbit at an inclination of 24 degrees. In this orbit, the mission’s six COSMIC-2 weather satellites, NASA’s Green Propellant Infusion Mission, General Atomics’ Orbital Test Bed satellite, the NPSAT 1 microsatellite from the Naval Postgraduate School, and the Prox-1 microsatellite from Georgia Tech — which contains the LightSail 2 CubeSat — will separate from the Falcon Heavy’s upper stage.
T+2:07:35: Second Stage Engine Restart
The Falcon Heavy’s Merlin upper stage engine reignites to begin climbing into a higher orbit.
T+2:08:04: SECO 3
The Falcon Heavy’s Merlin upper stage engine shuts down.
T+3:27:27: Second Stage Engine Restart
The Falcon Heavy’s Merlin upper stage engine reignites to reach the targeted orbit for the mission’s final payload.
T+3:28:03: SECO 4
The Merlin-Vacuum engine shuts down after reaching an elliptical orbit with a perigee, or low point, of 3,728 miles (6,000 kilometers), an apogee, or high point, of 7,456 miles (12,000 kilometers), and an inclination of 42 degrees to the equator.
T+3:34:09: DSX Separation
The Air Force Research Laboratory’s Demonstration and Science Experiments, or DSX, spacecraft separates from the Falcon Heavy’s second stage. The rocket will complete a “passivation” procedure in the next few hours, in which it will vent leftover propellant overboard. The venting will push the upper stage into a slightly different orbit from DSX.
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