WASHINGTON - An Atlas 5 rocket lifted off from Cape Canaveral Space Force Station at 12:30 a.m. Eastern on July 2, carrying 29 Amazon Leo satellites in what turned out to be the vehicle's final satellite-delivery mission. The satellites began deploying 21 minutes after liftoff, with all 29 safely released 16 minutes later.

With this launch, Amazon Leo now has over 390 satellites in orbit. “Still lots of work ahead - including raising all these new satellites to their assigned altitude - but we’ve completed enough launches for initial service this year,” said Chris Weber, Amazon Leo vice president, in a social media post that manages to sound both busy and optimistic.

This was the last of nine Atlas missions Amazon purchased from United Launch Alliance in 2021 for its broadband constellation, originally called Project Kuiper. The first launch carried prototype satellites in 2023; the other eight delivered operational satellites starting in April 2025. Amazon had also signed up for 38 Vulcan Centaur launches in 2022, but Vulcan has been delayed by development issues and an anomaly with a solid-rocket booster on its most recent flight in February. So Atlas 5, the old reliable, got the call.

“Atlas 5 has played a critical role in the early deployment phase for Amazon Leo, launching 224 satellites with a 100% success rate across all eight missions,” said Melissa Wuerl, Amazon Leo director of launch systems. She then added, with the confidence of someone who hasn't yet had to rely on Vulcan, “We’re excited to build on that foundation with ULA as we transition to Vulcan.”

Amazon has also flown three times on Arianespace’s Ariane 6 and SpaceX’s Falcon 9. Wuerl noted that “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.”

This launch was the final Atlas 5 flight to carry satellite payloads. The remaining six Atlas 5 vehicles in storage are reserved for Boeing’s CST-100 Starliner, a spacecraft that has had enough technical problems to make its launch schedule, if any, uncertain. The Atlas 5 has now flown 110 times since its introduction in 2002, with a perfect success rate except for one 2007 mission where the Centaur upper stage decided to nap early, leaving a spy satellite in a lower orbit than planned (though still usable).

The Atlas name dates back to the dawn of the Space Age, when it was developed as an intercontinental ballistic missile. Now it's retiring from satellite delivery, leaving the heavy lifting to newer, more finicky rockets. Progress, everyone.