A United Launch Alliance Atlas V 551 rocket, configured with five side-mounted solid rocket boosters and a medium-length payload fairing, carrying the Amazon Leo 4 mission lifted off on 16 December 2025 at 3:28 a.m. from Space Launch Complex-41 at Cape Canaveral Space Force Station.

Named LA-04 for Amazon’s fourth launch on a ULA Atlas V rocket, the mission added 27 satellites to the constellation, bringing the total number of Amazon Leo spacecraft launched to date to 180 satellites.

Atlas V deployed the satellites at an altitude of 289 miles (465 kilometers) above Earth, at which point the Amazon Leo team took over command of the mission from their mission operations center in Redmond, Washington. From there, initial satellite health checks were performed in preparation to raise the satellites to their assigned altitude of 392 miles (630 km), where they will be fully commissioned as part of the operational satellite constellation. IMAGE CREDIT AT RIGHT: UNITED LAUNCH ALLIANCE