This isn't good if you were planning on riding into space soon...

Henning said:
Well, that one picture does demonstrate that an explosion of the engine did not likely cause this failure.
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At least not in a way *you're* familiar with.

Nauga,
and Harry Callahan
 
weirdjim said:
Who the hell is Harry Callahan?
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Dirty Harry. "A man's gotta know his limitations." The spectators' gallery is full of 'experts' after an accident.

Nauga,
whose suits aren't vested but his interest is
 
weirdjim said:
Well, let's think about it. The failure was induced by the cold o-rings, agreed. But we've been using o-rings in the cold for a LONG, LONG time. How many hundreds of o-rings are there on any airliner that cruises above the freezing level. And how many hundreds of thousands of airliners, military aircraft have there been since the dawn of flight. SOMEWHERE along the line a cold o-ring ought to have given some real trouble but why this one at this time?

Sure, engineers tore the side engines off of prior launch vehicles and noted a slight bit or even a major bit of deterioration in the rubber after a launch. So if that was true even in WARM weather, why in the hell wasn't a different material (crush washer, mesh o-ring, ...) specified during the John Glenn era? There must have been a good design reason that THESE particular o-rings were subject to a stress beyond their design limits. Why? And the cold just made it worse.

Jim
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You said earlier that they didn't know about the O-ring problem until Feynman did a post mortem investigation. All I was saying is that was not the case. They knew there was significant deterioration and that cold weather conditions made the problems worse before the launch. Just because they got away with it on previous launches doesn't make that launch an great "anomaly" to use the lingo.

Secondly, o-rings in an airliner or automobile carburetor are used in different conditions and have different risks with regard to failure than they do in a solid fuel rocket booster.
 
nauga said:
At least not in a way *you're* familiar with.

Nauga,
and Harry Callahan
Click to expand...

True, I would expect to see a flame ball within a moment of an explosive engine failure, not an engine still running at what looks like a very low thrust setting amidst a cloud of what I presume is LOx.
 
Henning said:
True, I would expect to see...
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What you expect to see based on your preconceptions has no bearing on what happened. The opposite should be true but not necessarily.

Nauga,
who says 'carpe datum'
 
nauga said:
Any conclusions based on a single frame of video with no way of correlating it to the event 'front' are at best wild guessing. There are many sources of data that will be sifted through. Time and expert analysis will tell. You know I respect you, Ron, but guessing at this time is pointless.
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Noted, and appreciated, 'Naug.

Ron Wanttaja
 
Henning said:
True, I would expect to see a flame ball within a moment of an explosive engine failure, not an engine still running at what looks like a very low thrust setting amidst a cloud of what I presume is LOx.
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Weelll.... "Low Power Setting"="Random Burning" for solid rockets. I suspect we're just seeing it burn out.

Ron Wanttaja
 
wanttaja said:
Weelll.... "Low Power Setting"="Random Burning" for solid rockets. I suspect we're just seeing it burn out.

Ron Wanttaja
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Exactly, the NO2 supply had been removed and we're seeing residual heat and oxidation/burn process.

I found this an interesting read: http://en.m.wikipedia.org/wiki/SpaceShipTwo

2014 Change of engine manufacturer and hybrid engine fuel
In May 2014, Virgin Galactic took over engine development from Sierra Nevada[35] and announced a change to the fuel to be used in the SpaceShipTwo hybrid rocket engine. Rather than the rubber-based HTPB-fuel engine—engines that had experienced serious engine stability issues on firings longer than approximately 20 seconds—the engine would now be based on a solid fuel composed of a type of plastic called thermoplastic polyamide. The plastic fuel was projected to have better performance (by several unspecified measures) and was projected to allow SpaceShipTwo to make flights to a higher altitude.[42][43][44]

As of May 2014 when the version 2 engine by Virgin Galactic was publicly announced, the engine had already completed full-duration burns of over 60 seconds in ground tests on an engine test stand.[43] The second-generation engine design also required the modification to the SS2 airframe to fit additional tanks in the wings of SpaceShipTwo—one holding methane and the other containing helium—in order to ensure a proper burn of the new engine.[45] Additional ground tests were performed of the new engine between May and October 2014.
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I wonder what roll the helium and methane played? :dunno: Does anyone have a good explanation of how this engine works? A link maybe? My Googlefu is weak on this. I'm starting to see how an engine failure could be at the heart of this without a flame ball, but I would really love to see it diagramed or in a cutaway.
 
Ghery said:
Roger Boisjoly. Read more about it here. http://www.onlineethics.org/cms/7123.aspx
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It's got to suck bad to know you tried to stop the bosses from killing seven people and failed. I notice from the site that he spent retirement speaking on corporate ethics.

"If only I had been able to persuade them or crush X moron who refused to listen... they'd be alive..."
 
Henning said:
True, I would expect to see a flame ball within a moment of an explosive engine failure, not an engine still running at what looks like a very low thrust setting amidst a cloud of what I presume is LOx.
Click to expand...

How can you have LOx when there is nothing but NO on board as the oxidizer?

Jim
 
Those of you who have been speculating it wasn't an engine explosion may well be correct. From the NTSB briefing - it looks like it may have been a premature feathering initiated by the copilot:

B1fbB4sCYAAVPoF.jpg:large


I've been following this twitter feed:
https://twitter.com/NASAWatch
 
I heard the press conference live and the NTSB is going to have update this. The more he said, the less clear it was.

What I came away with is that the feather unlocked and being under power, uncommanded it moved from streamline to feather, which caused the pitch up and destruction. Imagine pushing a broomhandle with a great deal of force and then having a hinge in the middle of the handle. Continue force and it folds up. If the rocket force is greater than the aerodynamic pressures. . .even more so if you can imagine the force coming from just behind the hinge point.
 
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