The fourth launch of the United Launch Alliance (ULA) Atlas V 551 rocket carrying the next batch of production satellites for Amazon Leo (formerly Project Kuiper), Leo 4, is planned for Dec. 15, 2025, pending range approval. The launch window opens at 3:49 a.m. EST. This launch continues a new chapter in the commercial launch industry as Amazon Leo partners with ULA to deliver the majority of its advanced satellites to low Earth orbit (LEO). GO Atlas! GO Centaur! GO Leo!