I don't think I'd want to be on a vehical that has burning isulation no matter how "Normal" it is.
But on the other hand you'd have no problem riding on a (to use a cliché)
controlled explosion into orbit?
I don't think I'd want to be on a vehical that has burning isulation no matter how "Normal" it is.
But on the other hand you'd have no problem riding on a (to use a cliché) controlled explosion into orbit?
As long as the
controlled explosion is being directed in the proper direction from the proper ehxaust/chamber(s), everything is A-OK.
About the fire or so called fire. If this had lifted off in full view of the press with astronauts, it would have been all over the press and most regular folk would say it was unsafe to fly on (whether it was or not). You have to remember to the public they would not get on an airliner that was flying on fire and they sure as heck don't want astronauts flying on a rocket on fire. This would be a very hard sell. ULA needs to overcome this area when the vehicle is ever human rated.
The last couple pages seem to be focused on whether or not the ignition flare was acceptable.
How about a less contentious question:
Is the scale of the flare comparable to past launches?
My impression from watching a few videos of both Heavy and Medium configurations to compare to this launch is that the flare-up was larger than typical.
The pad and flame trench is not identical at SLC-6 to SLC-37, correct?
BTW, someone has added a fantastic image of this launch to the wikipedia article on SLC-6. I'm sure it's in other galleries, too, but I like it enough to single it out:
http://en.wikipedia.org/wiki/File:First_Delta_IV_Heavy_launch_from_SLC-6_at_Vandenberg_AFB.jpg
I really like the translucent flame that hydrogen makes. I might make myself a print of that shot.
It looks similar in size to the other Heavy launches. I think it just stuck closer to the vehicle than before causing more of the insulation to ignite.
It looks similar in size to the other Heavy launches. I think it just stuck closer to the vehicle than before causing more of the insulation to ignite.
Do you have an image of a prior launch which shows an example of actual flames on the vehicle (as opposed to charring) anywhere except aft (engine) end?
(Aft end was showing some hydrogen recirculation and burning on many flights)
To what extent can we know that this is not a new case of "normalisation of deviance", this time with Delta IV?
That seems like a reasonable question.
As regards the combustion of gaseous hydrogen, in general it appears
to me that it was once again easily tolerated by the vehicle and ground equipment. Scorch marks aren't a hazard, or even a sign of one.
The deviation on this launch was the bright spot apparently caused by combustion of something on the vehicle, subsequent to the hydrogen flare coming into contact with it. This secondary combustion appeared to have generated a visible amount of black smoke.
As Jim points out it did not last long, but I don't think it was expected, and I don't think any member of the general public knows what fueled that secondary flame or what extinguished it. As DaveS suggests we can safely assume ULA will investigate and take any appropriate corrective action.
My guess is that some product (perhaps a lubricant or adhesive) had been applied at that location, and that a small amount was inadvertently allowed to remain exposed on the vehicle exterior.
Either that, or some bird had started to build a nest.
Either that, or some bird had started to build a nest.
Nah, it had been up long enough for that nest to have been from last year. The chicks had grown and already flown the nest
It looks similar in size to the other Heavy launches. I think it just stuck closer to the vehicle than before causing more of the insulation to ignite.
Do you have an image of a prior launch which shows an example of actual flames on the vehicle (as opposed to charring) anywhere except aft (engine) end?
(Aft end was showing some hydrogen recirculation and burning on many flights)
Well, I was talking about the size of the fireball itself (which is what the person in the quote asked about). Of course the flames' behavior relative to the vehicle is a little different (probably due to the pad layout causing the H2 to be closer to the rocket). But the intertank area is likely covered with the same material as the aft end, which burns on every flight as you said, so it is not unexpected to see that burn in the presence of a closer-than-usual flame.
Pictures 10 and 11 on this page show the size of the fireball and the insulation on fire (as opposed to charred) on the demo flight:
http://www.ktb.net/~billmeco/delta4H.htmlBut I think the most important point of this whole discussion was stated just above by sdsds - if this was not expected, then they will figure out why it happened and whether it is acceptable. If it is not, then they will fix it. I can't imagine this would require an enormous modification to fix. Post-flight data analysis is routine for all launch vehicles and that is where this will be dealt with. And let us remember that the launch was successful in spite of this - and that is surely the most important thing.
Of course the fireball and charring were expected... but relatively prolonged burning of the outside of the rocket? I have a hard time those were either expected or desirable.
I do concur that it is kind of an impressive show, though!
I really don't know what all this fluff is about. The rocket lifted off, did its job, and we have a happy customer.
Too many people are making a mound out of a molehill. It's a minor non-issue, and they'll make it better next flight. Moving along...
I don't think I'd want to be on a vehical that has burning isulation no matter how "Normal" it is.
But on the other hand you'd have no problem riding on a (to use a cliché) controlled explosion into orbit?
The operative word here is CONTROLLED as opposed to "char-broiled" as we see in the pics.
I really don't know what all this fluff is about. The rocket lifted off, did its job, and we have a happy customer.
Too many people are making a mound out of a molehill. It's a minor non-issue, and they'll make it better next flight. Moving along...
There were a couple of SRB field joint blowbys before the Challenger accident and numerous foam strikes before the Columbia accident.
I don't know what the fix is but like someone else posted, this will have to be addressed before it could be man-rated.
Of course the fireball and charring were expected... but relatively prolonged burning of the outside of the rocket? I have a hard time those were either expected or desirable.
I do concur that it is kind of an impressive show, though!
That's the thing - most of us outsiders don't know what is expected and what is not for a rocket launch, unless it is clearly wrong (like the rocket self-destructing). Maybe it isn't desirable but is expected - I'm sure having a 100+ foot fireball engulf your rocket before it lifts off makes life harder for some engineers, but it is expected for this particular vehicle. We just don't know.
If this website had been around during the first D-IV flight in 2002, I am sure lots of people would have been arguing about whether it was normal for the bottom part of the rocket to be on fire as it went up. Of course we know now that it is normal - but at the time most of us probably wouldn't have known. (Unless they mentioned it in the webcast - I didn't see it)
We will find out for sure whether this was expected or not when the next Heavy flies from VAFB. If we see intertank burning, then it was expected or wasn't important enough to fix (like the aft part of the rocket burning in flight). If not, we know that they felt it was a problem and fixed it. I say we let the people who have the experience and do this for a living decide whether it is important and worth fixing or not.
From an arm chair review of the pad camera video:
1. Flame deflected upward to the level of the top of the boosters
2. No steam from water suppersion system early on
It appears there was late water suppession activation and the flame trench design didn't compensate for additional thurst volume of the vehicle. The Delta 4 Heavy launches at Canaveral don't exhibit the upward thurst discharge. SLC6 VAFB flame trench may need to be looked at for modifications. The booster insulation was clearly on fire.
The operative word here is CONTROLLED as opposed to "char-broiled" as we see in the pics.
If anyone ever thought that burning on the rocket was
uncontrolled, the rocket would never have left the ground in the first place before said burning was assured to be "controlled".
So yes, I find all the fuss about it funny, especially considering all the other, more violent ways a flight can go bad.
For all we know, the interstage sections could have been painted with a similar paint to the one used on the Saturn V platform and mentioned in this video:
Speaking of which... Almost the entire 1st stage of Saturn V used to get engulfed in flames at one point in flight and for a longer period than this, but I guess that never bothered anyone because it happened far from
expert eyes.
From an arm chair review of the pad camera video:
1. Flame deflected upward to the level of the top of the boosters
2. No steam from water suppersion system early on
It appears there was late water suppession activation and the flame trench design didn't compensate for additional thurst volume of the vehicle. The Delta 4 Heavy launches at Canaveral don't exhibit the upward thurst discharge. SLC6 VAFB flame trench may need to be looked at for modifications. The booster insulation was clearly on fire.
It is a dry flame trench, no water suppression.
Extra thrust? The ducts were designed for shuttle SRB's, no mods needed.
