Atlas V Sends Amazon's Twelfth Group of Leo Satellites Into Orbit
Amazon's Leo space-based internet constellation has been expanded again today, with the launch of its twelfth group of satellites.
Departing at 23:53 pm Universal Coordinated Time on May 29th from Space Launch Complex 41 in Florida, Atlas V headed towards low Earth orbit via the power of five solid rocket boosters and an RD-180 engine, bringing 29 Leo satellites from Amazon with it. The five boosters burned for a little over ninety seconds, while the RD-180 kept running for another three minutes afterwards. To continue ascent into orbit, the RL-10-powered Centaur upper-stage ran for about fourteen minutes to attain the customer's desired.
Deployment of the satellites began twenty-one minutes after launch, and occurred over sixteen and a half minutes, releasing all 29 Leo spacecraft.
The United Launch Alliance Atlas V rocket heads to space carrying 29 broadband satellites for @AmazonLeo, a network that will bring fast, reliable internet to customers and communities around the world. This is the Atlas V's seventh mission to help deplpy the Leo constellation. pic.twitter.com/tXsRbBBwN7
— ULA (@ulalaunch) May 30, 2026
With this deployment, Amazon now has 331 satellites to provide space-based internet services in orbit through twelve launches, from three providers. United Launch Alliance has performed the bulk of those with six previous missions, while SpaceX has performed three dedicated launches and Arianespace has conducted two.
Today's and previous groups are heading toward, or operating in, an orbital altitude of around 630 kilometers to prepare to provide internet services to customers. Following the deployment of further satellites, services from Leo are planned to be available later this year at speeds of up to one gigabit per second, something already demonstrated.
Of the now 331 satellites, United Launch Alliance has deployed the majority of them, releasing 197, to which Vice President of Atlas and Vulcan Gary Wentz shared:
"ULA has been a trusted launch partner since the beginning of the Amazon Leo program. Each mission we fly brings Amazon closer to enabling global connectivity, and we are proud to be a strategic partner launching the foundation of the commercial architecture for the Amazon Leo constellation."
Next time Leo satellites are placed into orbit by Atlas V, sometime in July, it will be the final time the launch vehicle has non-human spaceflight cargo. The remaining four flights, set to conclude before 2030, are dedicated to Boeing's Starliner.
The following flight after today's was set to have Amazon's largest group of Leo satellites to date launched, 48 of them, carried atop of Blue Origin's partially reusable New Glenn. On May 28th, however, the launch vehicle exploded during a qualification static fire. Leo's next deployment is now likely via Arianespace.
At the start of the year, Amazon sought a two-year extension with the U.S. Federal Communications Commission to launch half of the Leo constellation. That extension would move the deployment requirement of over 1,300 more satellites from July 2026 (two months from now) to July 2028. At present, it is still believed to be under consideration.
What is Atlas V?
Atlas V is United Launch Alliance's oldest two-stage rocket in service. The rocket is currently planned to be replaced by Vulcan when it retires before 2030.
The first-stage is powered by a single RD-180 generating 390 tons of thrust burning rocket-grade kerosene and liquid oxygen for four minutes and thirteen seconds. The RD-180 is manufactured by NPO Energomash in Russia.
The Centaur upper-stage is powered by either one or two RL-10 engines generating 10 tons of thrust each while burning liquid hydrogen and liquid oxygen for up to fourteen minutes and two seconds. Aerojet Rocketdyne, an L3Harris Technologies Company, manufactures the RL-10 engines.
Atlas V can also launch with between zero and five GEM-63 solid rocket motors to augment the rocket's thrust and payload capability. Each booster burns a solid propellant, consisting of Hydroxyl-terminated polybutadiene and Aluminum-Ammonium perchlorate, generating 169 tons of thrust each for a believed one minute and thirty-four seconds. Northrop Grumman manufactures the solid rocket boosters for use with United Launch Alliance.
Atlas V also has eleven different configurations with the following payload capacities: up to 18,814 kilograms to low Earth orbit, up to 8,900 kilograms to geostationary transfer orbit, or up to 3,850 kilograms to geostationary orbit.
