Author Topic: SpaceX Acknowledges Falcon 9 Engine Anomaly  (Read 45467 times)

Offline kevin-rf

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Re: SpaceX Acknowledges Falcon 9 Engine Anomaly
« Reply #40 on: 09/11/2011 12:56 am »
I understand this is their stuff and they can keep it under the rug if they want, but I'm not a fan of keeping important facts in file cabinets.

There is a difference between acknowledging an event happened and providing HD video of the event.

I am curious with the LOX rich shutdown if this is something they immediately knew about, or picked up after they did post flight analysis of the flight. Unlike a crushed tank, or a failed launch, with no stage recovery, the only clues to this will be in the telemetry... They have to identify an issue, determine what happened, the impact, and then a corrective action (if needed), then test the corrective action.

btw. Doesn't imploded imply a violent crushing and shredding of the tank? The crushed tank was more along the lines of a slow crushing of the tank as the tank was drained.
« Last Edit: 09/11/2011 12:59 am by kevin-rf »
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Offline Antares

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Re: SpaceX Acknowledges Falcon 9 Engine Anomaly
« Reply #41 on: 09/11/2011 02:13 am »
I am curious with the LOX rich shutdown if this is something they immediately knew about, or picked up after they did post flight analysis of the flight. Unlike a crushed tank, or a failed launch, with no stage recovery, the only clues to this will be in the telemetry... They have to identify an issue, determine what happened, the impact, and then a corrective action (if needed), then test the corrective action.

Ken said, "So because of that, when you get that mixture change happening, the temperatures can go up higher than you want inside the gas generator."  Bowersox added that "those temperatures could have damaged the turbines in the turbopump."

Turbine inlet (and sometimes outlet) temperature is a standard measurement on any engine.  If someone had it on their screen, they would have seen it as it happened.  There's only one way for the temperature to get higher and that's to run closer to stoichiometric.  Depletion sensors are standard on any rocket too, but discretes are hard to eyeball in real-time to see what happens first unless it was an obvious time lag.  So for him to say it was a LOX-rich shutdown, that implies it was looked at it in reviews.
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Offline edkyle99

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Re: SpaceX Acknowledges Falcon 9 Engine Anomaly
« Reply #42 on: 09/11/2011 03:27 am »
btw. Doesn't imploded imply a violent crushing and shredding of the tank? The crushed tank was more along the lines of a slow crushing of the tank as the tank was drained.

Unless you've seen the video, how could you possibly know this?  How do you know, for example, that the tank didn't pop violently, leak, catch fire, and explode?

 - Ed Kyle

Offline douglas100

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Re: SpaceX Acknowledges Falcon 9 Engine Anomaly
« Reply #43 on: 09/11/2011 07:31 am »

 We've never seen photos or videos of the Falcon 1 that imploded on the launch pad and never flew.  We've never seen the Falcon 1 Flight 1 crash and explosion video - something that has to have involved more than just SpaceX  - for many years now - since it happened on a U.S. range.  Etc.   

I haven't heard of the Falcon 1 that imploded on the pad. When did that happen?

A video of the Falcon 1 F1 crash was posted on this forum but taken down soon afterward. I caught it by accident. The rocket went straight up out of camera shot, the sound of the engine died away, then about twenty seconds later it dropped tail first out of the sky followed by a large KABOOM. The camera shook a bit. It was quite spectacular.
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Offline iamlucky13

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Re: SpaceX Acknowledges Falcon 9 Engine Anomaly
« Reply #44 on: 09/11/2011 08:17 am »
btw. Doesn't imploded imply a violent crushing and shredding of the tank? The crushed tank was more along the lines of a slow crushing of the tank as the tank was drained.

Unless you've seen the video, how could you possibly know this?  How do you know, for example, that the tank didn't pop violently, leak, catch fire, and explode?

 - Ed Kyle

It's been a while, but from my memory, the impression I had at the time it was originally discussed was a crumpling, which would fit the issue described (valve failure during drain), but I suppose it's not conclusively known it didn't get more dramatic.

About the engine, as I understand it, this is an email that was circulated beyond the intended audience:
http://www.spacekb.com/Uwe/Forum.aspx/space-policy/2348/Test-Failure-of-SpaceX-Merlin-VTS1-221Engine

But yes, it is still a disappointment that SpaceX has chosen not to share the full development experience. Unsurprising, but disappointing.

Online docmordrid

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Re: SpaceX Acknowledges Falcon 9 Engine Anomaly
« Reply #45 on: 09/11/2011 09:05 am »
Quote
[email protected] - 12 Sep 2005 19:12
>
SpaceX attempted a full Mission Duty Cycle (MDC) test of the Merlin S/N
003 engine on Wednesday, 7 Sep 05 with catastrophic results.
>

So, since when is something that happened in 2005 "news" in 2011?
« Last Edit: 09/11/2011 09:07 am by docmordrid »
DM

Offline Tony Ostinato

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Re: SpaceX Acknowledges Falcon 9 Engine Anomaly
« Reply #46 on: 09/11/2011 09:06 am »
"I want historians to know the real story"

boy has that ship sailed, that ship sailed so long ago it was made of reeds.

i wonder if this can be packaged as a wowza news story. since the flight was a success they'll have to explain why its not, and theres no way to explain anything short enough for the viewer not to tune out. most people tune out at the words space or rocket anyways.

and theres always other stuff goin on.



Offline edkyle99

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Re: SpaceX Acknowledges Falcon 9 Engine Anomaly
« Reply #47 on: 09/11/2011 04:02 pm »
"I want historians to know the real story"

boy has that ship sailed, that ship sailed so long ago it was made of reeds.

You don't know the dogged historians that I know! 

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Offline rcoppola

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Re: SpaceX Acknowledges Falcon 9 Engine Anomaly
« Reply #48 on: 09/11/2011 04:45 pm »
I have no doubt SpaceX and NASA are working the issues and will continue to do so for many years, especially as crewed operations move forward. It is very much in SpaceXs interest to ensure a robust, safe, successful vehicle. And if I were a relatively new entrant into spaceflight, I would suck the living marrow of knowledge out of NASA's bones while I had the chance.

Sail the oceans of space and set foot upon new lands!
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Offline Nomadd

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Re: SpaceX Acknowledges Falcon 9 Engine Anomaly
« Reply #49 on: 09/11/2011 04:58 pm »
And if I were a relatively new entrant into spaceflight, I would suck the living marrow of knowledge out of NASA's bones while I had the chance.


 That's a unique way to put it and a little disturbing.
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Offline rcoppola

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Re: SpaceX Acknowledges Falcon 9 Engine Anomaly
« Reply #50 on: 09/11/2011 06:01 pm »
And if I were a relatively new entrant into spaceflight, I would suck the living marrow of knowledge out of NASA's bones while I had the chance.


 That's a unique way to put it and a little disturbing.
Yes, perhaps too visual. Point being, by working closely with the incredible knowledge and experience of NASA personell and applying it to a commercial, vertically integrated, market competing company, the results, IMO, could be a truly spectacular future for Spaceflight. Which is supposed to be the point of this exercise...
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Online cuddihy

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Re: SpaceX Acknowledges Falcon 9 Engine Anomaly
« Reply #51 on: 09/11/2011 10:34 pm »
There seem to be two storylines at SpaceX: one pie-in-the-sky storyline, intended for the rubes in the media, as well as the un-payed forums and congress, that pretends to be above board and honest, but that ignores or downplays serious difficulties and risks, that perpetually maintains an astericked launch date on the calendar to the left of the "Real" date, and that will sue to keep the storyline in place.

The other is the real story, openly shared with Nasa and commercial customers, of which hints periodically appear (such as this one, or the quote from the NASA station folks that suggests the "Real" launch date for COTS 2/3 is some time in Jan or Feb of next year, with potential station rendezvous '[move to phase 3'] no earlier than Feb ) -- I predict the launch date slip to 2012 will be announced around Halloween, and will be subtly blamed on 'an inability to receive approval to approach the station until next year', possibly with additional reference to the 'fortuitous' soyuz failure that makes this particular range chicken game unnoticed.
« Last Edit: 09/11/2011 10:35 pm by cuddihy »

Offline Lars_J

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Re: SpaceX Acknowledges Falcon 9 Engine Anomaly
« Reply #52 on: 09/11/2011 11:22 pm »
There seem to be two storylines at SpaceX: one pie-in-the-sky storyline, intended for the rubes in the media, as well as the un-payed forums and congress, that pretends to be above board and honest, but that ignores or downplays serious difficulties and risks, that perpetually maintains an astericked launch date on the calendar to the left of the "Real" date, and that will sue to keep the storyline in place.

Take out any reference to SpaceX, and your paragraph could describe NASA itself, and any aerospace corporation.

The public story is never the whole story. It's called public relations.

Offline Jason1701

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Re: SpaceX Acknowledges Falcon 9 Engine Anomaly
« Reply #53 on: 09/11/2011 11:43 pm »
The other is the real story, openly shared with Nasa and commercial customers, of which hints periodically appear

Must not be a really shocking story or they'd have had trouble getting customers.

Offline edkyle99

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Re: SpaceX Acknowledges Falcon 9 Engine Anomaly
« Reply #54 on: 09/12/2011 02:47 am »
I haven't heard of the Falcon 1 that imploded on the pad. When did that happen?

It happened on December 19, 2005, during the first Falcon 1 launch campaign (which had seen a scrubbed first attempt on November 25, 2005).   The first stage was destroyed during fuel draining, after a scrub due to high winds, when the fuel pressurization system suffered a controller failure, causing the fuel tank to collapse.  The webcast was cut off, preventing any broadcast of the event.   

As a result, the first Falcon 1 flight used the second flight vehicle.  Even the second stage had to be replaced after the first second stage sprung a leak during a February 9, 2006 hot-fire test at Omelek.  The inaugural launch, which failed, did not occur until March 24, 2006.

 - Ed Kyle

Offline JohnFornaro

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Re: SpaceX Acknowledges Falcon 9 Engine Anomaly
« Reply #55 on: 09/12/2011 02:07 pm »
From the article:

Quote
"There was no explanation or root cause analysis or corrective action for this particular anomaly," Daniel said Sept. 9 during the public meeting. "This is a relatively troublesome statement not to recognize that a premature engine shutdown was a significant event..."

As Ed points out, the article is short on answering the various "W's".  This particular quote is certainly out of its original context, and meaningless in this article, since the news is that SpaceX is in fact starting to talk about the root cause analysis.

It sounds very much to me like "engine out was given a surprise test".  Murphy simply doesn't care if it's SpaceX or SLS.  Poop happens.  Go ahead and call it a surprise shutdown rather than engine out if you will.

As to transparency, the phrase "just like the O-ring on STS-51C" gave me some pause.  From the Wiki article:

Quote
During the investigation into the disaster, it was reported to the Rogers Commission that during the launch of STS-51-C, the worst solid rocket booster (SRB) blow-by effects of any mission prior to STS-51-L occurred, indicating conclusively that the Viton O-rings were not sufficiently sealing the hot gases inside the combustion chambers of the SRBs while firing.

The public transparency on 51-C, unfortunately, came to light after 51-L, not before.  I make no judgements on the order of the transparency, but there it is.  At the same time, there's a big difference between the two anolmalies.

Jim's analysis sounds right to me: "It is just an additional feature that will be eliminated from future vehicles."  Which means it's not a bug?  Whew.

Quote
It was like a pack of rhinos in the dessert when they spot a fire...

Huh?  Rhinos in the ice cream?
Sometimes I just flat out don't get it.

Offline Jim

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Re: SpaceX Acknowledges Falcon 9 Engine Anomaly
« Reply #56 on: 09/12/2011 02:23 pm »
The other is the real story, openly shared with Nasa and commercial customers, of which hints periodically appear

Must not be a really shocking story or they'd have had trouble getting customers.

Some of us only speak for NASA, can't say what they share with other customers.

Offline kevin-rf

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Re: SpaceX Acknowledges Falcon 9 Engine Anomaly
« Reply #57 on: 09/12/2011 02:48 pm »
It sounds very much to me like "engine out was given a surprise test".  Murphy simply doesn't care if it's SpaceX or SLS.  Poop happens.  Go ahead and call it a surprise shutdown rather than engine out if you will.

Where in the article does it state that the shutdown occurred before the planned shutdown time?

Maybe I have misread what has been published, but this is an event that happened during the planned shutdown of an engine or set of engines to one or more engines.

SpaceX has said nothing about any of the engines being shutdown before they planned to shut them down. That is not an engine out, engine out means an engine or set of engines quit early and the rest had to take up the slack. Maybe my reading skills are below par, but that is not what has been described as happening.

Based on what has been described and published, even if this Falcon 9 used a single Merlin 2 and this had happened the flight objectives would have been met. Apart from Saturn and Shuttle, can anyone come up with a real flight that was saved because of engine out?
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Offline douglas100

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Re: SpaceX Acknowledges Falcon 9 Engine Anomaly
« Reply #58 on: 09/12/2011 02:59 pm »
I haven't heard of the Falcon 1 that imploded on the pad. When did that happen?

It happened on December 19, 2005, during the first Falcon 1 launch campaign (which had seen a scrubbed first attempt on November 25, 2005).   The first stage was destroyed during fuel draining, after a scrub due to high winds, when the fuel pressurization system suffered a controller failure, causing the fuel tank to collapse.  The webcast was cut off, preventing any broadcast of the event.   

As a result, the first Falcon 1 flight used the second flight vehicle.  Even the second stage had to be replaced after the first second stage sprung a leak during a February 9, 2006 hot-fire test at Omelek.  The inaugural launch, which failed, did not occur until March 24, 2006.

 - Ed Kyle

Thanks for the information. I don't remember any mention of such a thing at the time. But maybe my memory's not what it used to be!
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Online billh

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Re: SpaceX Acknowledges Falcon 9 Engine Anomaly
« Reply #59 on: 09/12/2011 03:55 pm »
I seem to remember seeing a picture of the buckled Falcon 1 tank. Implode sounds like too strong a word.

I would love to see the video of the first failed Falcon 1 flight, but SpaceX is merely being prudent not to release it. Those who want to portray them in a negative light (and they are legion) would run that video any chance they got. It's just good business sense not to release it.

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