United Launch AllianceAtlas V 551Space Launch Complex 41, Cape Canaveral SFS, FL, USA
Amazon Leo (LA-04)
Launched
December 16, 2025 · 08:28 UTC
Image: ULA
Summary
Amazon Leo (LA-04) launched on an United Launch Alliance Atlas V 551 from Space Launch Complex 41, Cape Canaveral SFS, FL, USA on December 16, 2025 at 08:28 UTC. The launch window ran from 08:28 to 08:57 UTC. It was United Launch Alliance's 170th launch, 6th this year and humanity's 7,157th orbital launch attempt. It was the 19th Atlas V 551 flight and the 5th this year. The payload was bound for low Earth orbit (LEO). The tracked orbit of Kuiper-00144, one of 27 catalogued objects, from December 23, 2025, was 463 × 471 km inclined 51.9°. 27 objects from this launch are catalogued, all of them payloads.
- Watch
- Rocket Launch: Atlas V Leo 4United Launch Alliance
- Watch live: ULA Atlas 5 rocket launches 27 Amazon Leo satellites from Cape CanaveralSpaceflight Now
- ULA Atlas V 551 launches Amazon Leo Atlas 4 (LA-04)NASASpaceflight
- Booster
- No booster details on record.
- Mission
- Communications · Low Earth Orbit (LEO)for Amazon
- Milestone
- 19th Atlas V 551 flight · 5th this yearUnited Launch Alliance's 170th launch6th this yearhumanity's 7,157th orbital launch attempt308th orbital launch attempt this year
Webcast
Flight preview
Simulate in Flight ClubOrbit: as tracked
Kuiper-00144 · NORAD 67133 · 2025-301 · Space-Track · tracking 1 of 27 objects
Show the numbers for orbit elements
- Object
- TBA - TO BE ASSIGNED
- Object ID
- 2025-301A
- Epoch
- 2025-12-23 18:00:02 UTC
- Mean motion
- 15.35319315 rev/day
- Eccentricity
- 0.0006008
- Inclination
- 51.8693°
- Ascending node
- 72.0392°
- Arg. of perigee
- 114.2241°
- Mean anomaly
- 132.5396°
- Element set
- 999
- Rev at epoch
- 146
- B*
- 0.00092259
Perigee, apogee and period are Kepler figures from the catalogued mean elements, not a propagated state. Published orbit: LEO.
Flight timeline
- T−2.7SIgnition
- T+1SLiftoff
- T+34.7SSupersonic
- T+52.7SMax-Q
- T+1M46.6SBoosters Separation
- T+3M4.7SFairing Separation
- T+4M22.8SBECO
- T+4M28.8SStage 2 Separation
- T+4M38.8SSES-1
- T+17M32.8SSECO-1
- T+20M21.8SPayload Deployment Sequence Start
- T+35M11.8SPayload Deployment Sequence End
- T+54M14.7SSES-2
- T+54M25.7SSECO-2
- T+1H9M0.7SMission End
Catalogued objects
27 catalogued: 27 payloads; 27 still in orbit
- Kuiper-00144 · NORAD 67133 · in orbit
- Kuiper-00164 · NORAD 67134 · in orbit
- Kuiper-00175 · NORAD 67135 · in orbit
- Kuiper-00179 · NORAD 67136 · in orbit
- Kuiper-00181 · NORAD 67137 · in orbit
- Kuiper-00183 · NORAD 67138 · in orbit
- Kuiper-00184 · NORAD 67139 · in orbit
- Kuiper-00186 · NORAD 67140 · in orbit
- Kuiper-00187 · NORAD 67141 · in orbit
- Kuiper-00188 · NORAD 67142 · in orbit
- Kuiper-00191 · NORAD 67143 · in orbit
- Kuiper-00196 · NORAD 67144 · in orbit
Show 15 more payloads
- Kuiper-00204 · NORAD 67145 · in orbit
- Kuiper-00210 · NORAD 67146 · in orbit
- Kuiper-00221 · NORAD 67147 · in orbit
- Kuiper-00232 · NORAD 67148 · in orbit
- Kuiper-00241 · NORAD 67149 · in orbit
- Kuiper-00245 · NORAD 67150 · in orbit
- Kuiper-00246 · NORAD 67151 · in orbit
- Kuiper-00247 · NORAD 67152 · in orbit
- Kuiper-00248 · NORAD 67153 · in orbit
- Kuiper-00249 · NORAD 67154 · in orbit
- Kuiper-00250 · NORAD 67155 · in orbit
- Kuiper-00251 · NORAD 67156 · in orbit
- Kuiper-00252 · NORAD 67157 · in orbit
- Kuiper-00261 · NORAD 67158 · in orbit
- Kuiper-00265 · NORAD 67159 · in orbit
Data from J. McDowell, planet4589.org
About this launch
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.
Pad
Space Launch Complex 41, Cape Canaveral SFS, FL, USA
120th launch from Space Launch Complex 41, 6th this year · 1,076th from Cape Canaveral SFS, FL, USA
Local pad time at liftoff: Dec 16, 3:28 AM EST, at night
125 launches from this pad · 1,131 from Cape Canaveral SFS, FL, USA
32 days after the previous launch from this pad
Updates
Launch success.
Show 9 earlier updates
Liftoff
Nosu · 12/16/2025 · source
Official Webcast by United Launch Alliance has started
LL2 · 12/16/2025 · source
Updated launch weather.
Cosmic_Penguin · 12/16/2025 · source
Delayed to December 16 due to launch site ground winds.
Cosmic_Penguin · 12/14/2025 · source
Updated launch weather, 20% GO.
Cosmic_Penguin · 12/13/2025 · source
Updated launch weather, 65% GO.
Cosmic_Penguin · 12/12/2025 · source
Updated launch window.
Cosmic_Penguin · 12/8/2025 · source
Tweaked T-0.
Cosmic_Penguin · 12/1/2025 · source
NET December 15.
Cosmic_Penguin · 11/21/2025 · source
Questions
When did Amazon Leo (LA-04) launch?
Amazon Leo (LA-04) launched on December 16, 2025 at 08:28 UTC. The launch window ran from 08:28 to 08:57 UTC.
Where can I watch Amazon Leo (LA-04)?
Coverage: Rocket Launch: Atlas V Leo 4; Watch live: ULA Atlas 5 rocket launches 27 Amazon Leo satellites from Cape Canaveral; ULA Atlas V 551 launches Amazon Leo Atlas 4 (LA-04). Watch the replay
What rocket launched Amazon Leo (LA-04)?
Atlas V 551, flown by United Launch Alliance. Atlas V 551 spec sheet
Where did Amazon Leo (LA-04) launch from?
Space Launch Complex 41, Cape Canaveral SFS, FL, USA. Liftoff was Dec 16, 3:28 AM EST local time at the pad.
What orbit did Amazon Leo (LA-04) reach?
The tracked orbit of Kuiper-00144, one of 27 catalogued objects, from December 23, 2025, was 463 × 471 km inclined 51.9°.
How many satellites did Amazon Leo (LA-04) launch?
27 payloads from this launch are catalogued, 27 of them still in orbit (Data from J. McDowell, planet4589.org).
Which program is Amazon Leo (LA-04) part of?
Amazon Leo. About Amazon Leo