Falcon 9 launch timeline with DART

November 23, 2021 Stephen Clark

A SpaceX Falcon 9 rocket is set for liftoff from Vandenberg Space Force Base, heading southeast over the Pacific Ocean with NASA’s DART asteroid deflection experiment.

The 229-foot-tall (70-meter) rocket is poised for takeoff from Space Launch Complex 4-East at Vandenberg Space Force Base, California, at 10:21:02 p.m. PST on Nov. 23 (1:21:02 a.m. EST; 0621:02 GMT on Nov. 24).

The payload for the mission is NASA’s Double Asteroid Redirection Test, or DART, mission. The first-of-its-kind mission will take aim on a binary asteroid next September, guiding itself to strike the smaller of the pair.

The target asteroid, named Dimorphos, is about the size of a football stadium. Scientists will use ground-based telescopes to measure how much the kinetic impact from DART changed the orbit of Dimorphos around its larger companion, named Didymos.

The experiment will demonstrate how a future spacecraft could be launched to nudge an asteroid off of a collision course with Earth. Didymos and Dimorphos, the asteroid system targeted by DART, do not pose any near-term threat to our planet.

DART was developed by the Johns Hopkins University Applied Physics Laboratory, and funded by NASA. The entire mission costs $330 million, according to NASA.

The Falcon 9 first stage booster set to launch the DART mission has two previous flights to its credit. It first flew in November 2020 with the Sentinel-6 Michael Freilich oceanography satellite, then launched again in May with 60 Starlink internet satellites.

The second stage will perform a “dogleg” steering maneuver, or a left turn, early in its burn to align with the proper track for DART’s launch. The trajectory allows SpaceX to position its drone ship for the first stage landing a proper distance away from Isla Guadalupe, a Mexican island west of Baja California.

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

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 the SLC-4E launch pad at Vandenberg Space Force Base.

T+0:01:00: 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+0:01:12: 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+0:02:33: MECO

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

T+0:02:36: 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+0:02:44: 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-Vacuum engine ignites for a five-and-a-half-minute burn to put the rocket and DART spacecraft into a preliminary parking orbit. The second stage will perform a “dogleg” maneuver early in its burn to align with the proper track for DART’s launch.

T+0:03:11: 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+0:06:40: Stage 1 Entry Burn Begins

A subset of the first stage’s Merlin 1D engines begin an entry burn to slow down for landing. A final landing burn will occur just before touchdown.

T+0:08:06: 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 around Earth. The upper stage and DART begin a coast phase scheduled to last more than 20 minutes before the second stage Merlin Vacuum engine reignites.

T+0:08:52: Stage 1 Landing

The Falcon 9 rocket’s first stage booster touches down on SpaceX’s drone ship “Of Course I Still Love You” in the Pacific Ocean.

T+0:28:37: 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 DART spacecraft on an Earth escape trajectory.

T+0:29:30: 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 53-second burn to put the DART spacecraft on the proper trajectory to escape Earth’s gravity.

T+0:55:40: DART Separation

NASA’s 1,358-pound (616-kilogram) DART spacecraft separates from the Falcon 9 rocket’s second stage.

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