Success
Amazon Leo (LA-04)
Communications
United Launch Alliance(ULA)CommercialAtlas V 551
LEOorbit
Amazon Leo, formerly known as Project Kuiper, is a mega constellation of satellites in Low Earth Orbit that will offer broadband internet access, this constellation will be managed by Kuiper Systems LLC, a subsidiary of Amazon. This constellation is planned to be composed of 3,276 satellites. The satellites are projected to be placed in 98 orbital planes in three orbital layers, one at 590 km, 610 km and 630 km altitude. 27 satellites are carried on this launch.
Tuesday, December 16, 2025 at 8:28 AM
Replay
Flight Timeline
- T-00:03Ignition
- T+00:01Liftoff
- T+00:35Supersonic
- T+00:53Max-Q
- T+01:47Boosters Separation
- T+03:05Fairing Separation
- T+04:23BECO
- T+04:29Stage 2 Separation
- T+04:39SES-1
- T+17:33SECO-1
- T+20:22Payload Deployment Sequence Start
- T+35:12Payload Deployment Sequence End
- T+54:15SES-2
- T+54:26SECO-2
- T+1:09:01Mission End
Links
Mission details
Amazon Leo is a satellite internet constellation aimed at providing high-speed, low-latency broadband connectivity to underserved and remote areas globally. The project involves deploying a constellation of low Earth orbit (LEO) satellites to create a satellite internet network capable of delivering reliable internet access.
Oct 16, 2023 — ongoing
Orbital Attempt
#7,157
ULA Mission
#170
Pad Launch
#120
Location Launch
#1,076
Designator
2025-301
Weather GO
90%
Weather Concerns
Cumulus Cloud Rule
Launch Window
NET
Dec 16, 2025, 8:28 AM
Precision
Minute
Schedule Changes
1 update
Atlas V 551 Specs
Atlas V is an expendable launch system in the Atlas rocket family. It was formerly operated by Lockheed Martin and is now operated by United Launch Alliance (ULA), a joint venture with Boeing. Each Atlas V rocket uses a Russian-built RD-180 engine burning kerosene and liquid oxygen to power its first stage and an American-built RL10 engine burning liquid hydrogen and liquid oxygen to power its Centaur upper stage. The RD-180 engines are provided by RD Amross, while Aerojet Rocketdyne provides both the RL10 engines and the strap-on boosters used in some configurations. The standard payload fairing sizes are 4 or 5 meters in diameter and of various lengths. Fairings sizes as large as 7.2 m in diameter and up to 32.3 m in length have been considered. The rocket is assembled in Decatur, Alabama and Harlingen, Texas.
Length
59.7 m
Diameter
3.8 m
Launch Mass
573 t
Thrust
12,269 kN
LEO Capacity
18,850 kg
GTO Capacity
8,890 kg
GEO Capacity
3,850 kg
Launch Cost
$153M
Reusable
No
Maiden Flight
2006
Fastest Turnaround
23d 19h
Total Launches
21
Successful
21
Failed
0
Consecutive Success
21
Maiden flight: Jan 19, 2006
Social Flight Log
- Dec 16, 2025, 10:03 AM
Launch success.
Source - Dec 16, 2025, 8:28 AM
Liftoff
Source - Dec 16, 2025, 8:07 AM
Official Webcast by United Launch Alliance has started
Source - Dec 16, 2025, 6:38 AM
Updated launch weather.
Source - Dec 14, 2025, 6:43 PM
Delayed to December 16 due to launch site ground winds.
Source - Dec 13, 2025, 10:40 PM
Updated launch weather, 20% GO.
Source - Dec 12, 2025, 3:22 PM
Updated launch weather, 65% GO.
Source - Dec 8, 2025, 4:13 PM
Updated launch window.
Source - Dec 1, 2025, 5:43 PM
Tweaked T-0.
Source - Nov 21, 2025, 3:14 PM
NET December 15.
Source
United Launch Alliance
United Launch Alliance (ULA) is a joint venture of Lockheed Martin Space Systems and Boeing Defense, Space & Security. ULA was formed in December 2006 by combining the teams at these companies which provide spacecraft launch services to the government of the United States. ULA launches from both coasts of the US. They launch their Atlas V vehicle from LC-41 in Cape Canaveral and LC-3E at Vandeberg. Their Delta IV launches from LC-37 at Cape Canaveral and LC-6 at Vandenberg.
Founded
2006
Administrator
Interim CEO: John Elbon
Total Launches
173
Successful
173
Failed
0
Pending
38
Consecutive Success
173
Cape Canaveral SFS, FL, USA
Cape Canaveral Space Force Station (CCSFS) is an installation of the United States Space Force's Space Launch Delta 45, located on Cape Canaveral in Brevard County, Florida.
Timezone
America/New_York
Local Launch Time
Dec 16, 2025, 3:28 AM
Total Launches
1,109
Total Landings
75
Coordinates
28.4889, -80.5778