Vulcan inaugural flight, VC2S - Peregrine Lander - CCSFS SLC-41 - Q3 2023

[FutureSpaceTourist]

https://twitter.com/jeff_foust/status/1661825203591061514

ULA says it's postponing the Vulcan static-fire test planned for later today after "the team observed a delayed response from the booster engine ignition system that needs further review." That requires rolling the vehicle back to the Vertical Integration Facility.

Edit to add:

https://twitter.com/sciguyspace/status/1661824579013050368

ULA statement:

Cape Canaveral Space Force Station, Fla., May 25, 2023 - United Launch Alliance is standing down from the engine flight readiness testing today. During the countdown, the team observed a delayed response from the booster engine ignition system that needs further review prior to proceeding with the flight readiness firing. We will be rolling the rocket back to the Vertical Integration Facility to gain access to the booster ignition system. The team will continue to review data and determine when Vulcan can roll back to the pad to conduct the flight readiness firing.

[Robert_the_Doll]

https://twitter.com/ulalaunch/status/1661824360246804480?cxt=HHwWgIDQ-e2c_o8uAAAA
https://twitter.com/ulalaunch/status/1661824363375779846?cxt=HHwWjIDToYWd_o8uAAAA

[whitelancer64]

Tory says they will not static fire at full power, so wonder what power they WILL try to get to?

Per a Tory Bruno Tweet, Vulcan FRF peaks at 60% throttle and will last for about 6 seconds. As part of the FRF they will throttle down and simulate a MECO to end the FRF. The remainder of the test will be to follow on-pad abort protocols, including safing and detanking the rocket.

In this tweet thread Tory also says that firing the engines at full throttle would damage the pad, and then he said "I like my pad the way it is"

"The FRF will target about 60% power and last around 6 seconds. Short for a flight, but long for sitting on a pad."

https://twitter.com/torybruno/status/1661720817959591936

"I like my pad the way it is"

https://twitter.com/torybruno/status/1661419552377565184

[FutureSpaceTourist]

https://twitter.com/torybruno/status/1661834466032238592

Standing down for today. We test the BE4 ignition system during the count. Timing and response doesn’t look right. Need to understand it.

[Kiwi53]

https://twitter.com/torybruno/status/1661834466032238592

This would be the very first time ever that anybody has tried to start and fire more than one BE-4 at the same time, wouldn't it? Maybe it's not as easy as it should be

[ZachS09]

https://twitter.com/torybruno/status/1661834466032238592

This would be the very first time ever that anybody has tried to start and fire more than one BE-4 at the same time, wouldn't it? Maybe it's not as easy as it should be

As a wise one once said, “This is why we test. We’ll launch when we’re ready.”

[Robert_the_Doll]

This is rather an interesting situation since we did not see this much earlier during the first propellant loading on this stage and then prior to that two years ago on the pathfinder stage which went through a full simulated countdown with cutoff at T -0.

[Rakietwawka2021]

How is possible that Igniters worked with delay? Torch Igniters are quite simple so I can't even imagine what went wrong

[Damon Hill]

Torch igniters may be relatively simple, but staged combustion engine startup is complex, as per SSME/RS-25.  Lots of things have to happen correctly in the space of a few seconds.

[Vettedrmr]

This is rather an interesting situation since we did not see this much earlier during the first propellant loading on this stage and then prior to that two years ago on the pathfinder stage which went through a full simulated countdown with cutoff at T -0.

(just a guess) Maybe they didn't go through the startup ignition sequence, since they weren't going to fire the engines?

[Robert_the_Doll]

This is rather an interesting situation since we did not see this much earlier during the first propellant loading on this stage and then prior to that two years ago on the pathfinder stage which went through a full simulated countdown with cutoff at T -0.

(just a guess) Maybe they didn't go through the startup ignition sequence, since they weren't going to fire the engines?

That makes no sense. If the Pathfinder countdown went through the same test sequence, then it follows that the ignition test sequence was also done. Either it was a different form of torch igniter design for the Pathfinder or something happened during the Certification-1 booster's last full propellant  loading a few months ago.

But it is not as if they do not have time to work this problem. There is nothing about the Centaur V test article leak failure as yet. Delaying the test firing until June then is not much of an issue and it is better to understand what is going on rather than push blindly forward.

[Steve G]

The silence from Tory Bruno is deafening. He hasn't made a single tweet since May 25th of the one stating they are standing down.

[deadman1204]

The silence from Tory Bruno is deafening. He hasn't made a single tweet since May 25th of the one stating they are standing down.

Maybe he doesn't have anything specific to say.
There isn't actually a need to post something each day to belay message board rumors.

[Steve G]

Tory typically tweets every day and often multiple times a day. It's been over a week of silence.

[Mdmurphy12]

Hopefully just on vacation.