ULA launches 29 Leo satellites for Amazon
ULA early this morning successfully placed 29 Leo satellites for Amazon’s internet constellation, its Atlas-5 rocket lifting off from Cape Canaveral Space Force station in Florida.
This was the heaviest Atlas-5 payload so far launched by ULA, and ULA’S fifth launch for Amazon’s Leo constellation, which now has 241 satellites in orbit, out of the 1,616 it needs to launch by July to meet its FCC license requirement. Because it is not expected to meet that requirement, the company has asked for a time extension, which the FCC is presently considering.
ULA is in the process of retiring the Atlas-5 rocket. It now has only nine Atlas-5 rocket left in stock, with three reserved for Leo launches and six for Boeing’s Starliner manned capsule (though there is a good chance some if not all of the Starliner launches will be switched to other payloads).
This was also ULA’s second launch in 2026, which means the leader board for the 2026 launch race remains unchanged:
41 SpaceX
16 China
5 Rocket Lab
4 Russia
SpaceX continues to lead the entire world combined in total launches, as it did in both ’24 and ’25.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
ULA early this morning successfully placed 29 Leo satellites for Amazon’s internet constellation, its Atlas-5 rocket lifting off from Cape Canaveral Space Force station in Florida.
This was the heaviest Atlas-5 payload so far launched by ULA, and ULA’S fifth launch for Amazon’s Leo constellation, which now has 241 satellites in orbit, out of the 1,616 it needs to launch by July to meet its FCC license requirement. Because it is not expected to meet that requirement, the company has asked for a time extension, which the FCC is presently considering.
ULA is in the process of retiring the Atlas-5 rocket. It now has only nine Atlas-5 rocket left in stock, with three reserved for Leo launches and six for Boeing’s Starliner manned capsule (though there is a good chance some if not all of the Starliner launches will be switched to other payloads).
This was also ULA’s second launch in 2026, which means the leader board for the 2026 launch race remains unchanged:
41 SpaceX
16 China
5 Rocket Lab
4 Russia
SpaceX continues to lead the entire world combined in total launches, as it did in both ’24 and ’25.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
The last two satellites deployed with (a sim of) the Strait of Hormuz behind the Centaur craft.
Too bad that ULA did not get a deal to second source that RD-180 engine. It would be sweet even today. I guess Musk failed to get Russian engine either, which got Musk to do Merlin project, which is not as sweet as RD-180 but still a workhorse.
Robert Zimmerman,
Given that only three or four of the six Atlas Vs reserved for Starliner missions are ever likely to be used for that purpose, the obvious purchaser for the excess would seem to be Amazon Leo. But these Starliner launchers-in-waiting have only a pair of GEM 63 solid rocket boosters (SRBs) apiece so three more such SRBs would need to be acquired for each to make Amazon Leo launchers of them. One hopes Northrop Grumman still has the tooling for these. It would probably be a bit of a job to sub-in, say, the longer and heavier GEM 63 XL model SRBs now in production for Vulcan.
Then there’s the matter of the Centaur upper stages for the Starliner Atlas Vs having two RL-10 engines apiece rather than the singleton on the Atlas V 551s used thus far for Amazon Leo deployments. These notionally repurposed Atlas Vs would be 552 models according to ULA’s standard nomenclature – the only such ever built should that happen. One supposes the extra oomph provided might allow for a few more satellites to be carried by each of these Atlas V 552s if it proves possible to fit more within the payload fairings.
It will be interesting to see what eventuates anent all of these matters.
George C,
I believe it was Aerojet Rocketdyne that had a shot at getting all the data needed to produce RD-180s on its own. My understanding is that AJR concluded it could not produce RD-180s as cheaply as the Russians were willing to sell them so it passed – one of many reasons the US space patch was in wretched shape before Elon Musk came along.
Musk never tried to buy Russian engines, per se, he was after entire launch vehicles. The Russians famously dissed him and turned him down – one of a seemingly limitless pool of bad Russian decisions made during the past half-century even if it pales compared to deciding to invade Ukraine for a second time. Ah well, Russkies can be reliably counted upon to always, in the end, be Russkies.
All of the RD-170-derived Russian engines have been good pieces of kit. Whether the RD-180 is “sweeter” than the SpaceX Merlin 1-D depends on what scale you’re using to measure relative sweetness. The RD-180 operates at a much higher chamber pressure – and yields a correspondingly higher Isp both at sea level and in vacuum. The RD-180 is also an oxygen-rich staged combustion engine, not a gas generator design as is the Merlin. But the Merlin has a 2-1/3 times better thrust-to-weight ratio than the RD-180.
The Merlin is also known to be quite reusable. Perhaps the RD-180 would be too, but we will likely never know as it has never had the good fortune to power a reusable launch vehicle. And – given the continually declining state of the Russian space industry – most probably never will unless the Ukrainians undertake such a project once they have defeated and dismembered Russia.
RD-180 is essentially an RD-170 cut in half…two nozzles instead of four.
RD-170 rivaled F-1 in power. The later used “fences,” the four multiple nozzles to deal with instability.
A combination of both approaches might allow even more powerful engines.
NK-33 (N-1) was to be Kistler’s choice.
Energia’s RD-0120 SSME/ RS-25 equivalent
https://buranarchive.space/picture?/4786/category/rd-0120
That used channel wall.
I blame Bill Clinton for a lot of things—poor relations with Russia by siding with Islam over Serbs/Slavs—putting that fool Dan Golden in NASA.
Dick,
“But these Starliner launchers-in-waiting have only a pair of GEM 63 solid rocket boosters (SRBs) apiece so three more such SRBs would need to be acquired for each to make Amazon Leo launchers of them.”
Well, either that, or Amazon just has to live with a reduced payload capability (about 5,400kg, to be more precise) on that launch — fewer satellites. Might still be better than nothing, if NG can’t produce more GEM 63’s.
Heaviest Atlas V payload… What were the numbers in kilos?
Jeff Wright,
I’m familiar with the RD-180’s family tree. The RD-170 and RD-180 have multiple combustion chambers in addition to multiple nozzles. Only the turbo-machinery in the powerheads is shared.
You are also correct that this arrangement was the Soviet Union’s way of dealing with otherwise intractable combustion instabilities in large single-chamber liquid-fueled rocket engines. The Rocketdyne engineers developed the work-around of “fencing” the F-1’s injector pate into four quadrants, each of which proved capable of supporting a stable combustion locus within a single chamber. You pays your money, you takes your choice.
Perhaps some future large engine will combine these approaches, though I have my doubts. Following in SpaceX’s Raptor footsteps, more and more new engines are full-flow staged combustion units. These inject their propellants into a combustion chamber as already-burning gases, not liquids. Thus, there is no injector plate to “fence.” This approach certainly seems more mass-efficient as the Raptors have thrust-to-weight ratios notably better than those of both the F-1 and the Russian RD-170 family.
But never say never, I suppose. It certainly is an open question as to just how far that “fence” idea can be taken. Can a single monster engine – that has an injector plate that can be fenced, support, say 8 separate combustion loci stably? 16? 32? More? Had Truax ever had the opportunity to actually attempt his Sea Dragon – which I mention as I know it is among your favorite old-timey paper rockets – I think he would have been forced to find out.
Richard M,
Yes, Amazon may well have to settle for lofting fewer birds on each repurposed Starliner-configured Atlas V – assuming both that Amazon Leo indeed purchases ULA’s leftovers and that no additional GEM 63s can be obtained. Needs must, better had as the Brits like to say.
Being in charge of Amazon Leo must really be a thankless job. All of your intended launch service providers have defaulted in varying degrees – except the Main Enemy to whom you have been forced to go, cap-in-hand, at least twice. Then, to try spackling over the yawning chasm in your service offering timeline – and keep all of those putative clients you have cozened with bargain-basement initial pricing and who are now likely becoming increasingly restive – you are forced to pursue a purchase of Globalstar which is, unfortunately for you, 20%-owned by another of your major competitors in a different line of business. Can’t seem to win for losing.
Geoffrey M Carman
18,800 kg. according to the best info I could find. The decay of modern journalism is evidenced by all of the outlets that had no more to say on this matter than that it was the “heaviest-ever Payload” for an Atlas V.
I would think a combination of approaches would lend itself to re-use. Falcon was made to work first and foremost, re-use later.
I read that commonality is key to cost reduction, but Elon already has two different engines—I don’t think three would kill him.
It might be best for Raptors to just be used for booster return, with simpler but more powerful engines used for ascent.
Strap-on plastic kerosene tanks might look inelegant, but Phil Bono wasn’t above using something similar.
Post-Apollo engines:
https://forum.nasaspaceflight.com/index.php?topic=22068.msg1471218#msg1471218
Between Great Society/Vietnam…it was spaceflight that took the hit.
Elon goes public—-I fear it will be a death knell.
Dick Eagleson wrote:
“”Being in charge of Amazon Leo must really be a thankless job. All of your intended launch service providers have defaulted in varying degrees – except the Main Enemy to whom you have been forced to go, cap-in-hand, at least twice.””
I wonder if it is an option to use a Falcon Heavy flight and put up more LEO units with each launch? It would be a way to show the FCC you are serious.
Dick Eagleson: At 18.8Kilos, that means only about 1000 KG more than the average Starlink mission, which includes margin for landing…
Reminds you of how flexible a Falcon 9 is!!!
Jeff Wright: a third engine type gives SpaceX little they can’t get through some other path, and it increases their costs. Same with using strap-on tanks. Your propositions would slow down turnaround time without a commensurate benefit.
So far as going public, Musk will retain control with a majority of voting shares. It does not matter if there are other shareholders if they cannot vote on the path the company takes.
Jeff Wright,
To what Nate P said I can only add that, should SpaceX require a larger engine than whatever the end-state of Raptor development turns out to be, it could simply build a physically larger Raptor. Full-flow staged combustion engines don’t seem to be subject to the same combustion instabilities as engines that inject liquid-state propellants into their combustion chambers.
Ronaldus Magnus,
The Falcon Heavy is not really a useful option. It uses the same payload fairing as the F9 and would be volume-limited to a less than maximum load of Amazon Leos. There’s also the matter of the FH’s center core being effectively expendable as well as the 2nd stage. The FH is, in effect, less reusable than the F9 and, unlike their shared 2nd stage, SpaceX is not set up to mass produce FH center cores. The FH has its uses, but lofting Amazon Leo sats is not going to be one of them.
Geoffrey M Carman,
It reminds one of how powerful the F9 1st stage is – roughly twice the thrust of the Atlas V 1st stage and without any need for any Mama’s little helpers in the form of expensive and disposable strap-on solid rocket boosters.
Nate P,
Correct about retention of control of SpaceX. Elon is going to invite more people along for the ride, but he’s not going to let them steer. Mr. Wright’s expressed fears, like most of his enthusiasms, are ill-founded.