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ULA Atlas V 551 launches Amazon Leo Atlas 4 (LA-04)

ULA Atlas V launch of the Amazon Leo Atlas 4 (LA-04) mission from SLC-41. Launch Window: December 15th from 3:49AM to 4:18AM EST (08:49-09:18 UTC) Current T0: December 15th at 3:49AM EST (08:49 UTC) Mission: Atlas V 551 launch of a batch of 27 Amazon Leo satellites Launch location: Space …

Amazon Leo (LA-04)

Overview

Destination: Low Earth Orbit
Mission: Communications

Low Earth Orbit Space Launch Complex 41 Cape Canaveral SFS, FL, USA Probability: 65%

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.

Updates

Cosmic_Penguin • Dec. 12, 2025, 3:22 p.m.

Updated launch weather, 65% GO.


Cosmic_Penguin • Dec. 8, 2025, 4:13 p.m.

Updated launch window.


Cosmic_Penguin • Dec. 1, 2025, 5:43 p.m.

Tweaked T-0.


Cosmic_Penguin • Nov. 21, 2025, 3:14 p.m.

NET December 15.


Atlas V 551

Family:
Configuration: 551

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.

Specifications
  • Minimum Stage
    1
  • Max Stage
    2
  • Length
    59.7 m
  • Diameter
    3.8 m
  • Fairing Diameter
    5.4 m
  • Launch Mass
    573.0 T
  • Thrust
    12269.0 kN
Family
  • Name
    Atlas V 551
  • Family
  • Variant
    551
  • Alias
  • Full Name
    Atlas V 551
Payload Capacity
  • Launch Cost
    $153000000
  • Low Earth Orbit
    18850.0 kg
  • Geostationary Transfer Orbit
    8890.0 kg
  • Direct Geostationary
    3850.0 kg
  • Sun-Synchronous Capacity

United Launch Alliance

United Launch Alliance

(ULA)

CEO: Tory Bruno Founded: 2006 Successes: 169 Failures: 0 Pending: 42

Agency Type:

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.

INFO WIKI

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