ulalaunch
United Launch Alliance started the Atlas V rocket's countdown at exactly 6:05:30 a.m. EDT (1005:30 UTC) for the second of 46 recurring launches we will perform to deploy a majority of Amazon's Project Kuiper broadband satellite constellation in low Earth orbit, bringing fast, reliable internet to customers and communities around the world.
Activities are on schedule for liftoff to occur today at 1:25:30 p.m. EDT (1725:30 UTC) from Space Launch Complex-41 at Cape Canaveral Space Force Station in Florida. The available launch window remains open until 1:54:30 p.m., a duration of 29 minutes.
The countdown started from the T-minus 6 hours, 20 minutes point with two pre-planned built-in holds scheduled in the count. One 30-minute pause is reserved prior to fueling at T-minus 2 hours, the other 30-minute hold occurs prior to the terminal count at T-minus 4 minutes.
The application of power to the Atlas and Centaur stages is underway at the start of today's countdown procedures. The stages are being powered up to begin launch day testing and final preparations for fueling operations.
Over the next few hours, final preps for the liquid oxygen and liquid hydrogen systems will be performed, along with first stage propulsion and hydraulic preps, a test of the rocket's guidance system, internal battery checks and testing of the GPS Metric Tracking system used to follow the rocket as it flies downrange, plus a test of the S-band telemetry relay system.
Our live, play-by-play updates from Atlas Launch Control will begin at 10 a.m. EDT (1400 UTC) as we prepare for loading cryogenic propellants into the rocket.