Follow the key events of the Falcon 9 rocket’s ascent to orbit with the fourth set of 10 next-generation satellites for Iridium’s voice and data relay fleet.
The 229-foot-tall (70-meter) rocket will lift off Friday at 5:27 p.m. PST (8:27 p.m. EST; 0137 GMT) from Vandenberg Air Force Base in California.
SpaceX will not attempt to recover the first stage on Friday’s mission.
Data source: SpaceX
T-0:00:00: Liftoff
After the rocket’s nine Merlin 1D engines pass an automated health check, the Falcon 9 is released from Space Launch Complex 4-East at Vandenberg Air Force Base, California.
T+0:01:14: Max-Q
The Falcon 9 rocket reaches Max Q, the point of maximum aerodynamic pressure. The first stage’s nine Merlin 1D engines produce about 1.7 million pounds of thrust.
T+0:02:33: MECO
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.
T+0:02:38: Stage 2 Ignition
The second stage Merlin 1D vacuum engine ignites for an approximately 6-and-a-half-minute burn to inject the Iridium Next satellites into a parking orbit.
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.
T+0:09:00: SECO 1
The Merlin 1D vacuum engine turns off after placing the Iridium satellites in a temporary parking orbit, beginning at 43-minute coast in space.
T+0:51:54: Stage 2 Restart
The Falcon 9’s second stage engine ignites again for an 11-second burn to circularize its orbit.
T+0:52:05: SECO 2
The Merlin 1D vacuum engine shuts down after reaching a target orbit about 388 miles (625 kilometers) high with an inclination of 86 degrees.
T+0:57:05: Begin Iridium Deployments
The 1,896-pound (860-kilogram) Iridium Next satellites begin deploying from their two-tier dispenser on the Falcon 9 rocket’s second stage, separating at intervals of approximately every 90 seconds.
T+1:12:00: End Iridium Deployments
The last of the 10 Iridium Next satellites will separate from the rocket.
The U.S. Air Force on Monday certified the latest version of SpaceX’s Falcon 9 rocket, featuring higher-thrust engines, enlarged fuel tanks and a super-chilled propellant mixture, for launches of the military’s most valuable satellites.
An unexpected reading from a ground sensor prompted SpaceX to scrub the planned launch of a Falcon 9 rocket Thursday with 60 more Starlink broadband satellites. It was the second last-minute abort of a rocket launch on Florida’s Space Coast in less than 10 hours, following a hold Wednesday night just before engines ignited on a United Launch Alliance Delta 4-Heavy rocket.
The long queue of satellites waiting on launches aboard SpaceX’s Falcon rockets — a backlog the company says is worth $7 billion — will stay grounded while investigators determine what caused a Falcon 9 booster to disintegrate after liftoff Sunday.
