United Launch Alliance sent its final Atlas 5 rocket in a 551 configuration into the sky early Thursday, lifting 29 Amazon Leo broadband internet satellites from Cape Canaveral Space Force Station and closing out a version of the vehicle that had been part of the company’s launch lineup for nearly two decades.
Liftoff from Space Launch Complex 41 came at 12:30:15 a.m. EDT on July 2, 2026, after a countdown that began Wednesday morning and a day of final launch preparations that moved from the Vertical Integration Facility – Government to the pad, then through fueling and hold points before flight. The rocket flew north-easterly after leaving the pad, and ULA confirmed deployment of the satellites at 1:30 a.m. EDT.
The mission, called Atlas 5 Amazon Leo 8 by ULA and also known as Leo Atlas 8 or LA-08, was the company’s eighth Amazon Leo flight on Atlas 5. Melissa Wuerl said the rocket had now launched 224 satellites across those eight missions with a 100 percent success rate, a tally that underlines why this launch mattered beyond the single payload on board. For Amazon Leo, 29 more spacecraft now join the constellation as it pushes farther into service.
The numbers around the flight explain why the launch drew attention. The 45th Weather Squadron had given the window an 85 percent chance of favorable weather, and ULA used the 551 version of Atlas 5, a configuration defined by its five-meter fairing, five solid rocket boosters and a Centaur upper stage with one engine. This was the 22nd Atlas 5 551 launch, starting with New Horizons on Jan. 19, 2006, and the 110th Atlas 5 flight overall.
But the end of one chapter does not mean the rocket family is finished. Six Atlas 5 rockets remain reserved for Boeing’s CST-100 Starliner spacecraft, and those fly in the N22 configuration, the only Atlas 5 variant with a dual-engine Centaur upper stage. That leaves the 551 as the configuration that just ended, even as the broader Atlas 5 line still has work left to do.
Amazon Leo has said it will move to Vulcan for future missions, which makes this flight a handoff as much as a finish. The company has already said the next phase is meant to increase launch and deployment cadence, but no date for the next Vulcan flight was given in connection with this launch.
