Follow the key events of the Falcon 9 rocket’s ascent to orbit with the second set of 10 next-generation satellites for Iridium’s voice and data relay fleet.
The 229-foot-tall (70-meter) rocket will lift off Saturday at 1:25:14 p.m. PDT (4:25:14 p.m. EDT; 2025:14 GMT) from Vandenberg Air Force Base in California.
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+0:01:09: 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+0:02:24: MECO
The Falcon 9’s nine Merlin 1D engines shut down.
T+0:02:28: Stage 1 Separation
The Falcon 9’s first stage separates from the second stage moments after MECO.
T+0:02:35: 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+0:03:16: 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+0:05:48: Stage 1 Entry Burn
A subset of the first stage’s Merlin 1D engines ignite for an entry burn to slow down for landing. A final landing burn will occur just before touchdown.
T+0:07:45: Stage 1 Landing
The Falcon 9 rocket’s first stage booster touches down on SpaceX’s drone ship in the Pacific Ocean.
T+0:09:04: 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+0:52:06: Stage 2 Restart
The Falcon 9’s second stage engine ignites again for a 3-second burn to circularize its orbit.
T+0:52:09: 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+0:57:10: 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.
For the second consecutive day, SpaceX called off a Falcon 9 launch attempt at Cape Canaveral on Thursday evening, this time to complete a software update on the first 60 satellites for the company’s Starlink network to provide high-speed Internet service from orbit.
Acting NTSB Chairman Christopher Hart briefs the news media on Saturday, soon after arriving at the Mojave Air & Space Port to begin an investigation into the loss of Virgin Galactic’s SpaceShipTwo.
United Launch Alliance fired an Atlas 5 rocket into space from Cape Canaveral at 9:14 a.m. EDT (1314 GMT) Sunday with the U.S. Air Force’s X-37B spaceplane, an automated reusable mini-space shuttle designed to host experiments for years in orbit, then return to Earth and land on a runway. A launch attempt Saturday was scrubbed by bad weather.
