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.
Boeing specialists working inside a former space shuttle hangar in Florida started fueling the company’s first spaceflight-ready Starliner capsule this week ahead of the ship’s rollout to its launch pad later this month. The fueling milestone is a major step in the Starliner launch campaign, and comes after engineers concluded that human error led to a parachute deployment malfunction during a crew capsule abort test Monday.
Seven astronauts and cosmonauts are gearing up for launches April 9 and April 22 to the International Space Station, replacing seven outgoing crew members set to land in Kazakhstan and off the coast of Florida on April 17 and April 28.
SpaceX scrubbed the planned launch of its next set of Starlink satellites Friday. A Falcon 9 rocket is awaiting liftoff from pad 39A at the Kennedy Space Center in Florida with 57 Starlink Internet satellites and two commercial Earth-imaging microsatellites for BlackSky.
