28.03.2026
ULA postpones Atlas V launch try
First up, ULA's Amazon Leo 5 mission is scheduled to lift off from Launch Complex 41 at 3:53 a.m., with a 29-minute launch window extending to 4:22 a.m. The Atlas V will launch to the northeast about three hours before sunrise, carrying 29 broadband satellites. No Central Florida sonic booms should occur.
However, ULA officials announced a looming threat of high winds and cumulus clouds only give this mission a 10% chance of "go for launch weather." Those forecast odds jump up to 70% during the backup launch window, which is scheduled 24 hours later.
Amazon boosts investment in Cape launch facilities
Sunday's mission will occur days after Amazon Leo officials announced plans to double the growing constellation's annual launch rate. The company has launched more than 200 satellites — and has six more stacked payloads awaiting launch at its 100,000-square-foot satellite processing facility at NASA's Kennedy Space Center.
"We’ve also invested more than $200 million in infrastructure and service upgrades at ULA launch facilities at Cape Canaveral Space Force Station in Florida. These include a dedicated vertical integration facility for Amazon Leo (VIF-A), a new rail system and second mobile launch platform to transport the stacked rocket to the pad, and a second transport ship for carrying rocket boosters from ULA's factory in Alabama to Cape Canaveral," an Amazon press release said.
"The improvements will allow ULA to double their launch capacity and reduce turnaround time between launches, benefiting Amazon Leo and other ULA government and commercial customers operating from Space Launch Complex 41," the press release said.
ULA's Amazon Leo 4 mission lifted off from Launch Complex 41 at 3:28 a.m. Dec. 16. That Atlas V with five boosters carried 27 satellites into low-Earth orbit.
Quelle: Florida Today
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ATLAS V TO LAUNCH AMAZON LEO 5
ULA's Atlas V rocket will deliver another batch of satellites into low Earth orbit for Amazon Leo, the broadband constellation. Its mission is to provide fast, reliable internet to customers around the world, including those in unserved and underserved communities, using a network of more than 3,000 LEO satellites.
Launch Date and Time: To be announced
GO Atlas! GO Centaur! GO Amazon Leo!
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(Cape Canaveral Space Force Station, Fla., March 28, 2026) – Due to predicted inclement weather, the fifth launch of the United Launch Alliance (ULA) Atlas V 551 rocket carrying the next batch of production satellites for Amazon Leo, Leo 5, has been delayed. The launch vehicle and spacecraft are healthy. A new launch date will be provided upon finalization of range approvals and deconfliction with the NASA Artemis II launch.
Quelle: ULA
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Update: 4.04.2026
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ULA’s Atlas 5 rocket launches its heaviest payload ever with fifth Amazon Leo mission
United Launch Alliance launched its latest Atlas 5 rocket, which carried a batch of 29 Amazon Leo satellites to low Earth orbit. The mission was the largest and heaviest payload carried to orbit by an Atlas 5 rocket to date, according to ULA.
The mission was called Amazon Leo 5 by ULA and Leo Atlas 5 (LA-05) by Amazon. This was the fifth launch of operational satellites by ULA and the ninth for the constellation, which included one flight by Arianespace’s Ariane 6 rocket and three flights on SpaceX Falcon 9 rockets.
Liftoff of LA-05 happened Saturday, April 4, at 1:46 a.m. EDT (0546 UTC). The rocket headed out on a north-easterly trajectory upon leaving the launch pad. U.S. Space Force meteorologists predicted a 90 percent chance of acceptable weather for the launch.
After completing its launch readiness review on March 26, the following morning, ULA began rolling out its 62.5-meter-tall (205 ft) rocket from its Vertical Integration Facility out to the pad at Space Launch Complex 41. The move began around 10 a.m. EDT (1400 UTC) and ULA reported a “hard down” at the pad at 11:16 a.m. EDT (1516 UTC).
However, with high winds forecast for the rocket’s original launch date of March 29, ULA was forced to push back the launch until the next available launch date at Cape Canaveral after NASA’s Artemis 2 launch.
The Atlas 5 rolled back to its hangar on Tuesday and returned to the pad Thursday.
The 29 Amazon Leo satellites were released starting about 21 minutes after liftoff. There were 10 deployment sequences, which ended about 17 minutes later. The RL10C-1-1 engine on the Centaur 3 upper stage then reignited about 55 minutes after liftoff for a disposal burn, which will end the mission.
The previous four missions for Amazon Leo launched on by Atlas 5 rockets carried 27 satellites each. ULA and Amazon Leo were able to increase the payload stack to 29 as “a result of detailed engineering work between ULA and Amazon,” according to ULA.
Amazon pointed to ULA’s use of the RL10C-1-1 engine on the rocket’s upper stage as a key reason why they were able to add two more satellites to the mission.
“While the engine has flown on previous missions, LA-05 marks the first time the program has completed the extensive engineering and safety analysis required to use it with our larger payload,” Amazon said in a blog post. “Our engineering teams capitalized on the additional performance margin, adding a fourth level to the previous three-tier dispenser configuration for Atlas 5.”
Quelle: SN
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Quelle: ULA