Pad damage

On Mon, 02 Jun 2008 22:22:50 GMT, "Brian Gaff"
wrote:

So then, what is the cause. Is it subsidence? Sounds like some ultrasound
testing might be in order in the trench.

....And weren't you also noting that the downlink audio had a
significant vibration to it? I'm now wondering if there was more to it
now, Brian.

OM
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On Mon, 02 Jun 2008 18:11:35 -0500, OM
wrote:

On Mon, 02 Jun 2008 22:22:50 GMT, "Brian Gaff"
wrote:

So then, what is the cause. Is it subsidence? Sounds like some ultrasound
testing might be in order in the trench.

...And weren't you also noting that the downlink audio had a
significant vibration to it? I'm now wondering if there was more to it
now, Brian.

And the disturbing increase in number and size of debris from a Tank
that was supposed to be the "best yet" (but in reality looks to be the
second worst since RTF.)

Related? Probably not, but with NASA seemingly unwilling to
acknowledge that the new Tank gave a far from stellar performance, its
hard to just dismiss the possibility.

Brian

In sci.space.history OM wrote:
On Mon, 02 Jun 2008 22:22:50 GMT, "Brian Gaff"
wrote:
So then, what is the cause. Is it subsidence? Sounds like some
ultrasound testing might be in order in the trench.

...And weren't you also noting that the downlink audio had a
significant vibration to it? I'm now wondering if there was more to
it now, Brian.

How much can come off an SRB without it being "fatal?" Could a chunk
of propellant have come-loose and detonated somewhere in the tunnel?
How about the liquid propellants?

Or perhaps something more prosaic - like someone left something behind
in the tunnel?

rick jones
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these opinions are mine, all mine; HP might not want them anyway...
feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH...

On Tue, 3 Jun 2008 00:11:23 +0000 (UTC), Rick Jones
wrote:

How much can come off an SRB without it being "fatal?" Could a chunk
of propellant have come-loose and detonated somewhere in the tunnel?
How about the liquid propellants?

....Interesting question. Anyone have any data on observances of such
situations in the past?

Or perhaps something more prosaic - like someone left something behind
in the tunnel?

....Are there any anti-NASA congressmen been reported missing since
Saturday who might have been in the Canaveral-Titusville area? :-)

OM
--
]=====================================[
] OMBlog - http://www.io.com/~o_m/omworld [
] Let's face it: Sometimes you *need* [
] an obnoxious opinion in your day! [
]=====================================[

On Jun 2, 8:11 pm, Rick Jones wrote:

How much can come off an SRB without it being "fatal?" Could a chunk
of propellant have come-loose and detonated somewhere in the tunnel?
How about the liquid propellants?


The solid propellant doesn't detonate and if a chunk came out, it
would mean there is a problem with the SRM. Impossible with the
liquids.

On Jun 2, 7:11 pm, OM wrote:
On Mon, 02 Jun 2008 22:22:50 GMT, "Brian Gaff"

wrote:
So then, what is the cause. Is it subsidence? Sounds like some ultrasound
testing might be in order in the trench.

...And weren't you also noting that the downlink audio had a
significant vibration to it? I'm now wondering if there was more to it
now, Brian.

The vibration was with camera mount and not the ride to orbit

Rick Jones wrote in news:g2227b$pdk$1
@usenet01.boi.hp.com:


How much can come off an SRB without it being "fatal?" Could a chunk
of propellant have come-loose and detonated somewhere in the tunnel?
How about the liquid propellants?

No. Most likely the pad's aged and deteriorated enough that it's
started to fall apart under the stress. Imagine what a full-up
Ares V might do to it with 10 million pounds or more of thrust...

Way back in the 70's, I had the unique opportunity to walk through
one of those trenches. I don't remember the lining being so clean
appearing; seemed like it was pretty sooty.

--Damon

OM wrote:
...And weren't you also noting that the downlink audio had a
significant vibration to it? I'm now wondering if there was more to it
now, Brian.


Some sort of resonance between the acoustic exhaust frequencies of the
SRBs or SSMEs?
If there was damaged caused, you'd expect it to be a lot more likely
that the SRBs would be involved, due to their far greater acoustic
shockwave output.
Although you can explain the shed concrete panels in the interior of the
flame trench (via the zipper effect after one shed in the high velocity
exhaust flow from the SRBs), those shifted panels on the ramp that
surrounds the flame trench proper are more worrying.
If the subsurface material that the pad is built on has shifted or
slumped from age and repeated launchings, then the whole pad may be
dangerous to use without major reconstruction, pretty much from the
ground up.
That would be very time-consuming and expensive.

Pat

Brian Thorn wrote:
Related? Probably not, but with NASA seemingly unwilling to
acknowledge that the new Tank gave a far from stellar performance, its
hard to just dismiss the possibility.


Did they have significant foam shedding?
From what I read only around five very small sections of foam shed
during ascent:
http://www.spaceflightnow.com/shuttl...d2/index2.html
It certainly looks to be in very good shape from the post separation
imaging.
Still, this is the first all-new ET incorporating all of the
post-Columbia loss improvements, so it should have had almost no foam
shedding at all.

Pat

Rick Jones wrote:
How much can come off an SRB without it being "fatal?" Could a chunk
of propellant have come-loose and detonated somewhere in the tunnel?
How about the liquid propellants?


That would be very bad from three different perspectives:
1.) The shed burning chunk of solid fuel would partially block the
nozzle throat as it exited, raising the internal case pressure for a
brief moment as it blew out of the exhaust nozzle. This could lead to
the catastrophic rupture of the SRB casing at its weakest point from
overpressure.
2.) With a piece of the central bore of the SRB grain missing, its
combustion area would increase, with the overall thrust and internal
pressure also increasing.
3.) Probably most dangerous of all, the void in the central bore of the
fuel grain from the missing chunk of fuel could mean that the insulating
effects of the solid fuel that protect the SRB casing itself from the
heat of combustion until the end of the SRB burn would be removed from
one section of the casing for several seconds at the end of the burn,
causing a section of it to overheat (as in red-hot) and lose its
structural strength, causing a hole in it. It would be something along
the lines of of the Challenger SRB leak all over again.
I very much doubt this happened though.
It would have showed up in no uncertain terms in the launch telemetry
from the ascending Shuttle as the thrust curve of one SRB would be very
abnormal - too high during the first part of the burn, too low during
its latter part.

Or perhaps something more prosaic - like someone left something behind
in the tunnel?


"I could of sworn that I parked the Toyota Tundra here. Where the hell
is it?
Oh... wait a minute..." :-D

Pat