Atlas V uses similar solids –but these have different noses…rounded…not pointy.

SLS wears strakes above the SRBs these days

Perhaps Vulcan needs them.

Could aerodynamics play a role here?

Atlas nozzles don’t seem to have these troubles–or is that luck of the draw?

With two F-1s, they could have kicked solids to the curb and replaced SLS’ SRBs to boot….but no

I hope I live long enough to see Centaurs atop Falcons.

1) The other parts of Vulcan seem to work really well. Vulcan’s flight control system was able to compensate for the asymmetric thrust, the BE-4s had enough additional roll control to stabilize the trajectory, and the new Centaur V had enough spare capability to compensate for the first stage’s reduced thrust. Quite the robust not-so-little vehicle. Now if only Northrop Grumman can get their manufacturing processes nailed down.

2) ATK doesn’t seem to have managed the ATK—>Orbital—>Northrop Grumman transition chain well. Besides this one ATK also had problems with the nozzle on one of the Cert-2 SRBs and on the BOLO booster test last year. It’s getting to be an annual issue.

In addition ATK is said to be having some fairly major problems on the GBSD program, to the point that the program is not able to advance through the acquisition gates. I haven’t followed the program too much, but the delays there seem pretty serious.

3) I think the first step will be to isolate the cause of the failure on the fault tree enough to rule out a common problem with the regular GEM-63s. That would allow the Atlas V to fly out some of its Starliner and Amazon manifest while ATK gets the Vulcan SRBs back up to snuff. Up to two Starliner and four Amazon missions might then be able to fly on Atlas this year.

4) I’m expecting ULA’s return-to-flight mission to be Starliner-1 on an Atlas V and Vulcan’s to be Amazon LV-01. That assumes the fault is not common to both types of GEMs.

5) It’s been confirmed that the next Ariane flight will be LE-02 in late March or early April. I expect LE-03 to follow in May or June. That would add another 72 Leos before the deadline.

mkent: I never claim to be a math whiz. Math error fixed. Thanks.

”Amazon has now launched 222 Leo satellites…”

212. 180+32=212.

And with that, Amazon Leo passes Starshield (198 acknowledged satellites) to become the third-largest satellite constellation in the world behind Starlink and OneWeb.

Note: The US government has launched 14 additional satellites with the Starlink form factor, but they are not part of the acknowledged Starshield constellation. They are probably initial prototypes and test satellites for block upgrades. For consistency’s sake I’m not counting Amazon’s prototype satellites either.

Second, poor ULA. Had they remained glitch-free I think they could have made their goal of 18-20 launches this year. Even at their current pace, they were on track to complete eight launches from the VIF-G / SLC-41 facility. With the new VIF-A / MLP-A at SLC-41 about to begin stacking, an additional eight launches per year seems plausible. Add an additional three launches from their newly upgraded pad at Vandenberg (scheduled for completion in July), and they’re up to 19.

So now that they are putting the finishing touches on the necessary infrastructure and the Pentagon and Amazon are finally delivering payloads to launch, this happens.

Ugh! Poor ULA! At least we have SpaceX.

And yes, once again ULA was lucky that the nozzle burn through happened on an outward facing side.

Had the burnthru happened on the core-facing side, debris might have impacted the BE-4s and ended things quickly.

NG is facing an unhappy customer.

This issue is likely going to delay further Vulcan launches, and will likely make it impossible for ULA to meet its goal of launching 16 to 18 Vulcan missions this year. It will also raise hackles within the Pentagon, which certified Vulcan for military launches in 2025. That certification will likely be questioned, and possibly even pulled.

There is a lot of online discussion now about that roll of the vehicle after the SRB event, and I think it really does look like they came closer to loss of the vehicle and the mission than they did on the Cert-2 flight. I think it has to be treated as a more serious failure, even if they appear to have got the payloads to the proper orbit.

ULA has now confirmed that the payloads have been successfully delivered:
https://x.com/ulalaunch/status/2021989144751198326

But ULA has also announced an official investigation into what happened:
https://newsroom.ulalaunch.com/releases/ula-vulcan-rocket-successfully-launches-the-future-of-defense

USSF announces they will “work closely” with ULA on the investigation before Vulcan launches again, in a rather ominouus press release:
https://x.com/SciGuySpace/status/2022005254066470989/photo/1

For the record, the investigation into the nozzle failure on Cert-2 lasted five months. The return to flight was about ten months. It is hard to say, without knowing a lot more, whether they will match those timelines. But this is definitely going to cost them some time.