4K Replay: ULA launches final Atlas 5 551 rocket, supporting Amazon Leo satellite constellation [2:23]

YouTube ^ | July 3, 2026 | Spaceflight Now

[SunkenCiv]

On Tuesday, July 2, United Launch Alliance launched the final Atlas 5 rocket flying in a 551 configuration. The rocket featured a five-meter payload fairing, five solid rocket boosters, and one RL10 upper stage engine. 

The mission, Atlas 5 Amazon Leo 8 (aka Leo Atlas 8), sent 29 satellites into low Earth orbit with deployment happening less than 30 minutes after liftoff. Amazon purchased nine flights onboard Atlas 5 rockets. The first of those launched the Protoflight mission in 2023, followed by eight batches of production satellites. 

The first Atlas 5 551 rocket launched on January 19, 2006, in support of NASA's New Horizons mission. 

4K Replay: ULA launches final Atlas 5 551 rocket, 
supporting Amazon Leo satellite constellation | 2:23 
Spaceflight Now | 3,849 views | July 3, 2026

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TOPICS: Business/Economy; Computers/Internet
KEYWORDS: amazonleo; atlas5; atlasv; ula

[SunkenCiv]

YouTube transcript reformatted at textformatter.ai *may* follow.

[SunkenCiv]

Watch live coverage of the launch of a United Launch Alliance Atlas 5 rocket with a batch of 29 satellites for Amazon's Leo internet service on Friday, May 29, 2026. Liftoff is scheduled during a 29-minute launch window that opens at 7:33 p.m. EDT (2333 UTC). The rocket will take a north-easterly trajectory on departure from Florida's Space Coast. 

Watch live: ULA Atlas 5 rocket launches from Cape Canaveral 
with 29 Amazon Leo satellites | 2:05:32 
Spaceflight Now | 111,142 views | Streamed live on May 29, 2026

YouTube transcript reformatted at textformatter.ai *may* follow.

[SunkenCiv]

Probably no point to either transcript -- "5, 4, 3, 2, 1, go Atlas, go ULA, go Leo..."

[Celtic Conservative]

It’s gonna kill Bezos to write checks to Musk for launches going forward. And yes, I’m aware Bezos has his own aerospace company. But not nearly as successful as SpaceX. Ref: the smoking crater formerly known as launch complex 36.

CC

[SunkenCiv]

Yup. Plus he doesn't like to write checks.

The Leos have also gone up on the Ariane 6, SpaceX Falcon 9, and I think there were a couple others. Falcon 9 has better payload capacity than most stuff currently flying, and beat the Delta IV Heavy (also a thing of the past) by a mile on cost, not on capacity.

The F9 launch total is likely to surpass 600 before the end of this year, and that's win-lose-draw on the Starship.

The Falcon Heavy beats Delta IV Heavy by quite a bit, plus it is (mostly) reusable while D4H was expended each time.

Theoretically the New Glenn exceeds the FH spec while being reusable, but even with the failures to land FH's core booster (that's been a problem) it's an operational system and costs a tad less to launch. NG is really still in development, has no launch cadence, and it remains to be seen whether the next launch attempt will take place in 2026.

[Campion]

There are several Atlas V's left, but all of them are being saved to launch Boeing Stayliner flights.

Meanwhile, the replacement for Atlas V, ULA's Vulcan, works ... except that the Northrup-Grumman solid rocket boosters have a nasty RUD ("rapid unscheduled dissassembly") problem, as in, they (only partially so far) come apart during flight.

Not something ready to carry people! Hopefully N-G gets their stuff figured out soon.

[SunkenCiv]

Whoops.

“The F9 launch total is likely to surpass 600”

s/b

“The F9 launch total is likely to surpass 700”