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Update July 2, 1:30 a.m. EDT (0530 UTC): ULA confirms deployment of the 29 Amazon Leo satellites.
United Launch Alliance closed a big chapter in the company’s history. Thursday morning’s predawn launch from Cape Canaveral Space Force Station in support of Amazon Leo’s satellite constellation was the final flight of an Atlas 5 rocket flying in a 551 configuration.
The rocket carried 29 broadband internet satellites onboard as part of the Atlas 5 Amazon Leo 8 mission, which was also referred to as Leo Atlas 8 (LA-08) by Amazon.
Liftoff from Space Launch Complex 41 happened 12:30:15 a.m. EDT (0430:15 UTC). The rocket flew on a north-easterly trajectory upon leaving the pad.
“Atlas 5 has played a critical role in the early deployment phase for Amazon Leo, launching 224 satellites with a 100 percent success rate across all eight missions, and we’re excited to build on that foundation with ULA as we transition to Vulcan,” said Melissa Wuerl, Amazon Leo Director of Launch Systems, in a statement. “With hundreds of flight-ready satellites standing by at the Cape and a new, dedicated vertical integration facility ready to support Leo Vulcan 1 and subsequent missions, we have a clear path to increase launch and deployment cadence, helping us quickly expand network coverage following an initial service rollout later this year.”
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The 45th Weather Squadron forecast an 85 percent chance for favorable weather during the 29-minute launch window. Meteorologists are tracking a small chance for interference from cumulus clouds.
After completing a launch readiness review on Tuesday, countdown to launch began at 7:49 a.m. EDT (1149 UTC) on Wednesday. Teams prepared to roll the 205-foot-tall (62.5 m) rocket from the Vertical Integration Facility – Government (VIF-G) to the launch pad.
Riding atop the Mobile Launch Platform (MLP), the Atlas 5 cruised down a set of train tracks about a third of a mile away to the launch pad. Once the “go to roll” call was granted at about 10 a.m. EDT (1400 UTC), the 1.9-million-pound (862,000 kg) MLP and Atlas 5 rocket began moving.
The MLP was lowered onto the launch pad piers at 11:11 a.m. EDT (1511 UTC), which established the status of “hard down.” After attaching the necessary umbilicals to the rocket and payload fairing, and removing the support cars, ULA began loading the rocket’s booster with RP-1, a rocket grade kerosene, at about 2:30 p.m. EDT (1830 UTC), which was complete an hour later.
United Launch Alliance rolled its final Atlas 5 551 rocket to the pad at Space Launch Complex 41 and is preparing to launch the Leo Atlas 8 mission at 12:24 a.m. EDT (0424 UTC) on July 2. Fuel loading (RP-1) on the Atlas booster began at 2:30 p.m. EDT (1830 UTC).
Timelapse:… pic.twitter.com/aHppLTtFn4
— Spaceflight Now (@SpaceflightNow) July 1, 2026
The rocket bears the company designation AV-114 from ULA and will be the 110th Atlas 5 rocket launched to date.
The 551 configuration denotes the fairing size (five meters), the number of solid rocket boosters, and the number of Centaur upper stage engines. There have been 22 Atlas 5 551 launches to date with the first supporting NASA’s New Horizon’s mission to Pluto, which launched on Jan. 19, 2006.
Following Thursday’s launch there will be just six Atlas 5 rockets remaining. All of those are reserved to fly Boeing’s CST-100 Starliner spacecraft.
Those rockets fly in the N22 configuration and are the only variant of an Atlas 5 rocket that feature a dual-engine Centaur upper stage. After the 2024 Crew Flight Test of Starliner in 2024 experienced several issues resulting in NASA declaring a Type A mishap, the cargo-only Starliner-1 launch date is in question.
Moving to the next chapter
Amazon Leo’s constellation of satellites is launched to space using a variety of launch providers in addition to ULA. It has flown three missions with each Arianespace and SpaceX, using their Ariane 6 and Falcon 9 rockets respectively.
The company also purchased 38 launches using ULA’s Vulcan rockets and 27 launches with Blue Origin’s New Glenn rockets. However, both of those launch vehicles remain grounded as they go through their own anomaly investigations.
Prior to the launch of the most recent Amazon Leo mission on an Ariane 6 rocket earlier this month, Steven Metayer, the vice president of Production Operations at Amazon Leo, said that there would be one more Ariane 6 launch supporting this constellation this year, but didn’t specify when in the next six months.
He said the first Vulcan flight of Amazon Leo satellites is expected to take place sometime in the third quarter of 2026. ULA stacked its Vulcan rocket inside its new VIF-A hangar and plans to conduct a wet dress rehearsal tanking test following the LA-08 launch.
After the launch, there will be 396 Amazon Leo satellites in low Earth orbit. The company aims to roll out early commercial service by the end of the year, but hasn’t stated how many satellites will be needed to begin this initial offering.
The tech giant has lined up a number of corporate clients, including most recently a deal with Hitachi Construction Machinery, which was announced on June 24.
“Under this agreement, Hitachi Construction Machinery will deploy portable Amazon Leo antennas at construction sites in the United Kingdom and Germany beginning in 2026, using satellite connectivity for critical service workflows including machine health reports, downloading service manuals in the field, receiving real-time maintenance alerts and uploading inspection reports,” Hitachi said in a press release.
