ULA launches 27 Amazon satellites from Florida

Liftoff for Kuiper-1 was at 7:01 p.m. EDT from pad 41 at Cape Canaveral Space Force Station. There was a two-hour launch window, and it could have been pushed back to Tuesday in case of bad weather again or technical problems.

About 3 1/2 hours later, at 10:34 p.m., rival SpaceX launched a Falcon 9 carrying 23 Starlink satellites -- 13 with direct-to-cell capabilities, from pad 39A at nearby NASA's Kennedy Space Center.

ULA had a 10-mile ring around the launch site for weather considerations.

Earlier on Monday, weather conditions had been listed as 70% favorable, according to ULA.

The 106.5-foot Atlas 551 booster put 27 Kuiper satellites into orbit at an altitude of 280 miles for high-speed Internet access to millions of people around the world. A few minutes later the first-stage booster was jettisoned before leaving Earth's atmosphere.

It was the 250th flight of a Centaur upper stage on an Atlas rocket.

The Atlas V 551 rocket, which is built by General Dynamics, is configured with five side-mounted solid rocket boosters and a medium-length payload fairing, according to ULA. The rocket elements were assembled inside the Vertical Integration Facility adjacent to the launch pad.

The Atlas Centaur's launches include eight trips to Mars.

Amazon plans to launch 3,232 Kuiper satellites by 2029, including half by mid-2026.

The Federal Aviation Administration in February 2023 approved the entire Project Kuiper after ULA dealt with the risks of orbital debris.

Last week, ULA President and CEO Tony Bruno said the company is targeting late spring or early summer for its next Kuiper Atlas launch. The company also is planning its first national security mission via a Vulcan rocket.

In October 2023, ULA launched two prototype Kuiper satellites into orbit for testing.

Amazon is building the satellites in Kirkland, Wash.

"We've designed some of the most advanced communications satellites ever built, and every launch is an opportunity to add more capacity and coverage to our network," Rajeev Badyal, vice president of Project Kuiper, said in a pre-launch blog posting. "We've done extensive testing on the ground to prepare for this first mission, but there are some things you can only learn in flight, and this will be the first time we've flown our final satellite design and the first time we've deployed so many satellites at once."

Rival SpaceX has launched 7,000 Starlink satellites for more than 5 million subscribers. Also, Eutelsat OneWeb also is entering the market for low Earth orbit satellites for internet usage.

United Launch Alliance LLC was formed in December 2006 as a joint venture between Lockheed Martin Space and Boeing Defense, Space & Security.