NASASpaceFlight.com Forum
Commercial and US Government Launch Vehicles => NGIS (Formerly Orbital ATK) - Antares/Cygnus Section => Topic started by: Bubbinski on 05/30/2019 01:12 pm
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I’m going to the OmegA test today for NSF.com. Will be taking pics and video, writing an article too.
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T-36 min to test
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Webcast link:
https://www.youtube.com/watch?v=8MTM-ANa7FI
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Five mins past the hour is the target.
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They’ve inserted the launch key, evacuated the crew to building T22, it’s getting real
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T-9 min hold for final system checks
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T-9 min and COUNTING!
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Promo video:
https://twitter.com/NASASpaceflight/status/1134172487003099137
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The family:
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Underway!
https://twitter.com/NASASpaceflight/status/1134174324494143488
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Nozzle broke apart at T+120 s?
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The nozzle shattered at the end?? :o
EDIT: Looked like a normal length burn, but that did NOT look nominal at the end.
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Whoops!
https://twitter.com/NASASpaceflight/status/1134174890465144832
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RIP Nozzle.
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Nozzle failure? Quick signoff?
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Nozzle broke apart at T+120 s?
Just before T+120 call out. So, at about T+118.
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Seemed that there was a Nozzle RUD at approximately 1:19 into the test firing.
Then instead of a replay, they signed off.
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Here are the screncaps of the anomaly I managed to get
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Could have been a lot worse. All seems to be a nozzle RIP.
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Seemed like they were doing a lot of gimballing throughout the test (a lot more than would be expected in flight), I wonder if that had anything to do with it?
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The best I can tell rewatching it is the nozzle breakup was accompanied by a strong burst of exhaust gas. I wonder if it was either the nozzle throat actually letting go as the initial failure, allowing out a big burst of gas out which the outer edges of the nozzle couldn't handle either or if it was the entire motor experiencing an overpressure event.
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Seemed like they were doing a lot of gimballing throughout the test (a lot more than would be expected in flight), I wonder if that had anything to do with it?
More importantly, if it IS an issue with the TVC system, what impact does this have on SLS?
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Seemed like they were doing a lot of gimballing throughout the test (a lot more than would be expected in flight), I wonder if that had anything to do with it?
More importantly, if it IS an issue with the TVC system, what impact does this have on SLS?
None, I'd think as the SLS FSBs uses modified STS hardware which lives inside a much larger and wider aft skirt.
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Full video:
https://www.youtube.com/watch?v=LLeY3J1tdLs
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Got some pics with my phone. Processing hi-res pics and video
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About 5 seconds before the nozzle popped, "Accumulator is enabled" was called out. I don't know if that's actually relevant, but it is true.
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Press conference at 2:05 pm Mountain
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Press conference at 2:05 pm Mountain
It will be live-streamed on the same stream that carried the test coverage.
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Press conference at 2:05 pm Mountain
For those of use who are timezone impaired, that should translate to 20 minutes from the time of this post.
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https://twitter.com/northropgrumman/status/1134183680765845504
#NorthropGrumman successfully completed the test of OmegA’s first stage; the motor performed nominally with an observation noted at the very end of test involving the aft exit cone of the nozzle. Tune in to the press conference starting at 2:05 p.m. MDT http://www.northropgrumman.com/OmegA
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Successful test, they say:
https://twitter.com/northropgrumman/status/1134183680765845504
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Presser started.
"Generally quite pleased with the test."
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4 years ago they said they’d test the rocket in May 2019, they made it there. Heated to 90 deg, higher thrust. Called it a success. Everything worked very very well, observed aft exit cone “doing something strange”
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Rominger: sparks during tailoff was the “strange event”, not connected with the normal black smoke by the quenching system
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The key part:
https://twitter.com/NASASpaceflight/status/1134190363768496128
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Harwood: What would the result be during the flight? Any commonality with SLS?
Rominger: getting quick look data within several hours. Could have had a normal, nominal thrust profile but need to analyze the data. Nozzle is different than SLS.
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Question of schedule impact:
Rominger: don’t know, as of now still on schedule for Aug/Sep Castor 300 test
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“This is why we test” - statement repeated just now
700 channels of data
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From the USAF point of view, integral part of development process: Sanjume - working very closely and plan forward from me. Press conference over
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"This is why we test" in play:
https://twitter.com/NASASpaceflight/status/1134191931465109509
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They "observed the aft cone doing something strange that we need to look at". An interesting set of euphemisms. :)
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4 years ago they said they’d test the rocket in May 2019, they made it there. Heated to 90 deg, higher thrust. Called it a success. Everything worked very very well, observed aft exit cone “doing something strange”
Is there any material on the test, that confirms this? I especially want to know whether this is Celsius or Fahrenheit.
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4 years ago they said they’d test the rocket in May 2019, they made it there. Heated to 90 deg, higher thrust. Called it a success. Everything worked very very well, observed aft exit cone “doing something strange”
Is there any material on the test, that confirms this? I especially want to know whether this is Celsius or Fahrenheit.
What that the Propellant Mean Bulk Temperature (PMBT) affects SRM performance? Yes there is, decades of it.
Here's one example, the first result off Google: https://tfaws.nasa.gov/TFAWS08/Proceedings/Presentations/TFAWS-08-1006_presentation.pdf
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4 years ago they said they’d test the rocket in May 2019, they made it there. Heated to 90 deg, higher thrust. Called it a success. Everything worked very very well, observed aft exit cone “doing something strange”
Is there any material on the test, that confirms this? I especially want to know whether this is Celsius or Fahrenheit.
This is the USA, so Fahrenheit.
They heat the entire booster in a giant heater over the course of several days, and they measure the internal temperature of the solid fuel to make sure it's at 90 before the test fire. Same thing for when they do minimum temperature test fire, they put it in a cooler for a week.
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Scott Manley’s edit(s) of the ‘incident’.
https://youtu.be/J6JKg1IQ5D0
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I wonder if the limited spread of the nozzle's failure was a case of good engineering or good fortune. That looks like it could have blown up the whole motor!
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I wonder if the limited spread of the nozzle's failure was a case of good engineering or good fortune. That looks like it could have blown up the whole motor!
It depends on the root cause... If a chunk of propellant came loose and struck the nozzle to make it fail, sure, but not if the nozzle was the root failure point. But if this happened in-flight as the tail end of the first stage burn, that would probably not be good - the stack could potentially be put under a lot of stress from asymmetric thrust.
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I wonder if the limited spread of the nozzle's failure was a case of good engineering or good fortune. That looks like it could have blown up the whole motor!
It depends on the root cause... If a chunk of propellant came loose and struck the nozzle to make it fail, sure, but not if the nozzle was the root failure point. But if this happened in-flight as the tail end of the first stage burn, that would probably not be good - the stack could potentially be put under a lot of stress from asymmetric thrust.
And without a nozzle there is no thrust vector control.
The rocket would be unguided.
While the cheerleaders say the thrust had fallen off there appeared to still be significant thrust at the time of “the event”.
Scott Manley called it a “failure”. How rude!
But it’s still good enough to compete with proven rockets for Air Force launch contracts.
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I wonder if the limited spread of the nozzle's failure was a case of good engineering or good fortune. That looks like it could have blown up the whole motor!
It depends on the root cause... If a chunk of propellant came loose and struck the nozzle to make it fail, sure, but not if the nozzle was the root failure point. But if this happened in-flight as the tail end of the first stage burn, that would probably not be good - the stack could potentially be put under a lot of stress from asymmetric thrust.
The followup question to my concern is, was the spread of the nozzle failure limited because of deliberate engineering or luck? If the failure continued further up the nozzle, I'm not sure that the propellant case would have survived.
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They "observed the aft cone doing something strange that we need to look at". An interesting set of euphemisms. :)
Yeah, it blew it's a$$ end off...
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Watching the video the exhaust plume seemed to get a lot brighter for a the last few seconds before it let go. Maybe that's normal or just the camera?
Either way, hard to call it a success when you lose a flight critical piece of the rocket during the test.
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ARTICLE: NGIS OmegA fires for two minutes in first static test – nozzle incident under review -
https://www.nasaspaceflight.com/2019/05/ngis-omega-fires-first-test-nozzle-incident-review/
- By Justin Davenport
NGIS screenshots and Justin Davenport photo.
https://twitter.com/NASASpaceflight/status/1134300777051111424
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From the USAF point of view, integral part of development process: Sanjume - working very closely and plan forward from me. Press conference over
Bravo to USAF and Northrop Grumman for showing the test, even the off-nominal bit, and talking about it in a press conference. It seems clear from the information shared with the public that some very good lessons will be learned from this test, thanks to the "strange" event at the end. That's why Rominger called it a "successful test".
- Ed Kyle
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From the USAF point of view, integral part of development process: Sanjume - working very closely and plan forward from me. Press conference over
Bravo to USAF and Northrop Grumman for showing the test, even the off-nominal bit, and talking about it in a press conference. It seems clear from the information shared with the public that some very good lessons will be learned from this test, thanks to the "strange" event at the end. That's why Rominger called it a "successful test".
- Ed Kyle
One certainly learns from all test failures, but that does not make it a "successful test". That's a very low bar for "success". And what would you call a test where the nozzle didn't fail?
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Putting a positive spin on a less-than-perfect outcome is hardly an action unique to NGIS. As rocket motor failures go, this one was a lot more benign than many (do I need to name names?) and more publicly presented.
I still wonder if all of the full range nozzle gimbaling had anything to do with the problem.
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I wonder if the limited spread of the nozzle's failure was a case of good engineering or good fortune. That looks like it could have blown up the whole motor!
It depends on the root cause... If a chunk of propellant came loose and struck the nozzle to make it fail, sure, but not if the nozzle was the root failure point. But if this happened in-flight as the tail end of the first stage burn, that would probably not be good - the stack could potentially be put under a lot of stress from asymmetric thrust.
And without a nozzle there is no thrust vector control.
The rocket would be unguided.
While the cheerleaders say the thrust had fallen off there appeared to still be significant thrust at the time of “the event”.
Scott Manley called it a “failure”. How rude!
But it’s still good enough to compete with proven rockets for Air Force launch contracts.
Is calling it a failure all that far off the mark though. It’s certainly something that could I thought have led to an actual launch failure?
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https://twitter.com/djsnm/status/1134376425132183552
Crossfading between before & after.
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Is calling it a failure all that far off the mark though. It’s certainly something that could I thought have led to an actual launch failure?
It's hard to say. They'll have to look at the data, but at the press conference they said that if it happened late enough in the test, it might have been endurable in flight.
That said, I'm still not convinced the people at the conference had seen the footage. They very well may watched the test in person, from several miles away, and then bused back to the office and went straight into the conference.
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We've gotta remember that this was the first Castor 600 test firing ever. The FIRST test. NGIS primary concern wasn't if, for example, the nozzle had enough ablator or the gimbal would work; they were asking big obvious simple questions.
Will it fire for as long as expected?
Will it produce anywhere near as much thrust as expected?
Will the casing hold?
Does it work at all?
And on all those counts, the test was a success. Those were the things that really mattered; everything else was a bonus.
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Is calling it a failure all that far off the mark though. It’s certainly something that could I thought have led to an actual launch failure?
It's hard to say. They'll have to look at the data, but at the press conference they said that if it happened late enough in the test, it might have been endurable in flight.
That said, I'm still not convinced the people at the conference had seen the footage. They very well may watched the test in person, from several miles away, and then bused back to the office and went straight into the conference.
Couldn’t all that shrapnel flying off it have done serious damage to the centre core?
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Is calling it a failure all that far off the mark though. It’s certainly something that could I thought have led to an actual launch failure?
It's hard to say. They'll have to look at the data, but at the press conference they said that if it happened late enough in the test, it might have been endurable in flight.
That said, I'm still not convinced the people at the conference had seen the footage. They very well may watched the test in person, from several miles away, and then bused back to the office and went straight into the conference.
Couldn’t all that shrapnel flying off it have done serious damage to the centre core?
This (the Castor 600) IS the center core. If it wasn't damaged by the shrapnel here, and it didn't appear to be, I don't see why it would be in flight. Especially since in flight, the shrapnel will fall away rather than around.
Now, if this happened much earlier in the test, while the GEM 60 boosters would still be attached in flight, that would probably be an issue. As is I don't think shrapnel is a problem.
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High resolution images:
https://twitter.com/astrogeo/status/1134278193085444096
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4 years ago they said they’d test the rocket in May 2019
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4 years ago they said they’d test the rocket in May 2019
That article is from three years ago! Maybe they became a more optimistic from the prediction in 2015. :-)
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First of all, thankyou to Northrop Grumman for showing this live. Who doesn't like seeing big motors being tested!
Here's the sequence of frames of the nozzle failure. We can clearly see a large fireball erupting from the left side of the nozzle along with some debris heading upwards.
I'm an engineer and I do tests all the time. When a test does not go to plan, my reaction is one of head down. There's a problem with the design that's going to take time to fix. Its the reason why we test, to get the bugs out of the design. I certainly don't jump out of my chair and shout "Success!". That's taurus excretus. When the test does work, that's when I give the fist pump and have a big smile on my face. :-)
Some engineering philosophy:
I was told and I forgot.
I saw and I remembered.
I did and I understood.
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One certainly learns from all test failures, but that does not make it a "successful test". That's a very low bar for "success". And what would you call a test where the nozzle didn't fail?
Clearly the motor, or at least the nozzle, suffered a failure during this test. This cannot happen during a flight, and now it won't happen thanks to this test. This was a "successful" test in the same way that the CST-100 and Dragon ground abort tests were "successful" - by rooting out flaws.
- Ed Kyle
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One certainly learns from all test failures, but that does not make it a "successful test". That's a very low bar for "success". And what would you call a test where the nozzle didn't fail?
Clearly the motor, or at least the nozzle, suffered a failure during this test. This cannot happen during a flight, and now it won't happen thanks to this test. This was a "successful" test in the same way that the CST-100 and Dragon ground abort tests were "successful" - by rooting out flaws.
- Ed Kyle
Agree very much with this.
I will say it draws into question the "low technical risk" rating, HOWEVER tests are tests. This is a very useful test.
And I REALLY don't like investing a bunch of money into OmegA/son-of-the-Stick (it cannot be rapidly reusable, which is essential to a shiny space future), but the NG/ATK/Orbital team has shown an impressive ability to lean forward and bend metal and layup carbon fiber. I will always respect a hardware-rich stance, even if I don't happen to like the architecture.
And I consistently want folks to do more hardware tests, not fewer, and part of that means accepting a significant possibility of uncovering real problems in those hardware tests. So I'm glad NG pushed for this test. And I'm not going to beat them up because it uncovered a problem.
NG had a bad day yesterday. But this what tests are for. And good on them for having the courage to go for it.
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I totally agree. Success and failure are rarely as black and white as we all like to pretend they are. Even if we start talking about payloads reaching orbit as successes and failures, that's whole cloth ignoring near-misses that are very clear failures of certain systems (Atlas V engine valve issue comes to mind).
Kudos to NGIS for airing this even with a very clear failure of the nozzle. Kudos to NGIS for hitting their schedule for static fire, that's really tough to do.
Speculation hat on: I think this was a burn through of the nozzle followed by a structural failure because of the burn through. If that's true, it's a very solvable problem.
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4 years ago they said they’d test the rocket in May 2019
That article is from three years ago! Maybe they became a more optimistic from the prediction in 2015. :-)
This seems like a great example of "Gradatim Ferociter". You plan to do a test 3-4 years from now. That's "Gradatim". Then you actually fire a big honking rocket engine for a full thrust, full duration test - that's "Ferociter".
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Scott Manley’s news report on the test as well as the OmegA launcher. He does put forward an argument in the video which I am assuming explains why he uses the word failure in the title.
[MEDIA=youtube]1mTCxpGSIbI[/MEDIA]
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I totally agree. Success and failure are rarely as black and white as we all like to pretend they are. Even if we start talking about payloads reaching orbit as successes and failures, that's whole cloth ignoring near-misses that are very clear failures of certain systems (Atlas V engine valve issue comes to mind).
Kudos to NGIS for airing this even with a very clear failure of the nozzle. Kudos to NGIS for hitting their schedule for static fire, that's really tough to do.
Speculation hat on: I think this was a burn through of the nozzle followed by a structural failure because of the burn through. If that's true, it's a very solvable problem.
I hope it's just a nozzle thermal or structural issue, but the "bang" sound and violent ejection of pieces suggest more than just a burn-through to me. My first guess was the nozzle throat insert failed from the mechanical/thermal stress of the firing, and just let go suddenly with a "bang," taking part of the exit cone with it.
Usually the throat insert is a separate torus of carbon/carbon material supported by the rest of the nozzle assembly. If there was a CTE mismatch or a manufacturing defect, the throat insert may just not have been able to take the stress.
The sequence of events also seems consistent with ejection of a chunk of propellant, impacting the nozzle throat and causing the "bang" and shattering the nozzle. But as you said, we can/should hope that wasn't the case.
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https://eu.floridatoday.com/story/tech/science/space/2019/09/19/northrop-grumman-says-omega-still-schedule-despite-test-fire-anomaly/2364085001/
Northrop Grumman concludes investigation into Omega rocket's test fire anomaly
“The nozzle exit cone break up that occurred at motor shut down was caused by a ground test phenomenon that would not have occurred in flight," the company said in a statement. "We have worked closely with the Air Force to study the issue and we are confident the Omega rocket will perform in flight as expected.”
Northrop Grumman wouldn’t go into further detail on what the ground test phenomenon was but noted the motor did fire for the full planned duration.