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STS51L Accident Questions



 
 
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  #61  
Old March 6th 05, 08:16 PM
OM
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You-Know-Who-Jr babbled:

1. You, nor anyone else here for that matter, have expressed an interest in
my genuine offer to share telemetry which I described as "nauseating".


....That's because nobody wants to see your father's kiddie porn.
Nobody normal, that is.

Again, kids, please. Just killfile every M***** and put them out of
our misery. Don't waste your time on them.

OM

--

"No ******* ever won a war by dying for | http://www.io.com/~o_m
his country. He won it by making the other | Sergeant-At-Arms
poor dumb ******* die for his country." | Human O-Ring Society

- General George S. Patton, Jr
  #62  
Old March 6th 05, 08:46 PM
Charleston
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"Herb Schaltegger" wrote:
"Charleston" wrote:

Facts:

1. You, nor anyone else here for that matter, have expressed an interest
in
my genuine offer to share telemetry which I described as "nauseating". I
did not even get a simple question back as to which telemetry I was
referring.


Perhaps if you posted excerpts (here directly, or via a link to
something specific on your site) along with an analysis of any
significance (e.g., why it is "nauseating"), you might draw some
serious interest.


The data would not fit here well and any subsequent posts would make it
become difficult to read. I will post the raw "as received" STS 51-L SRB
chamber pressure data in its entirety on my website
www.challengerdisaster.info tonight. Any serious comments would be
appreciated. I am willing to discuss my concerns about that data and why I
find it "nauseating" as long as anyone wants to discuss it in a serious
manner.

2. You, nor anyone else here for that matter, have offered any evidence
that the smoke to which I refer in videos on my website is "stuff" which
"shows up on every Shuttle launch" as suggested by Pat Flannery in the
following quote from an earlier post.

"That stuff coming off the side of the tank, and falling into the area
behind the ET isn't related to the SRB problem, it shows up on every
Shuttle launch; it's either some sort of venting from the ET or frost
falling off of its exterior surface."

Interesting given the 113 launches to date. I have seen some visual
evidence of nominal ET offgassing on numerous flights but only a few
flights
remotely resemble the 51-L smoke anomaly post T + 10 seconds.


Have you correlated the visual phenomena with ambient temperature,
pressure and relative humidity?


No, nor did NASA during its investigation into the disaster.

The "smoke" on your video clip looks
a lot more like condensed water vapor (e.g., a contrail forming from
ice shards shed by the ET flash-evaporating and immediately
recondensing/freezing in the cold, dry air that day), than true smoke,
at least to me, especially given the way the rest of the video
appeared to have contrast heightened.


I suppose one should ask him or herself what the smoke is supposed to look
like after the initial o-ring leak? At what point does that black smoke
leaking from a dynamically vibrating joint, transition from the products of
incomplete rubber o-ring combustion, to the pressurized SRB propellant gases
and fire. I believe the o-rings and associated grease and putty have a very
short/finite life expectancy when exposed to 5,900 degree Fahrenheit
temperatures at 950 pounds per square inch pressure (1 atmospehere). One
might also ask how NASA film experts ascertained (if they even did so) when
the o-ring combustion was finished so that any subsequent SRB joint leakage
could be properly identified as a leak of the bright SRB gases, smoke, and
eventually fire, everyone normally sees during a launch (out of the nozzles
of course). Again, exactly how long does one look for black smoke? Where
is this discussed in any engineering detail in the PC report? It is not
enough IMHO to state the joint was likely clogged with a chunk of putty and
then ignore or kiss off as vapor what we can see on M-2 and M-3--withholding
M-2 and M-3 from the Presidential Commission entirely, and from the public
until I made a FOIA request BTW.

This is
important given that I have yet to see a recovered ET other than 51-L to
determine what if any anomalies existed on those remotely similar
flights.


The STS Mission Data and In-Flight Anomalies List (a/k/a the "Green
Book" - I don't have my 1991-version handy for the NASA publication
number) would have detailed descriptions of any anomalies; from that
you could form FOIA requests for post-flight inspection photos and
test data of the ET segments if you found any correlation.


The PC report discussed these issues in some detail on flights prior to STS
51-L except for STS 51-J. The ASAP annual reports have discussed various
potential SRB leak and pressure deviation issues since STS 51-L (mostly
associated with the nozzles).

The ET of course is not recovered and that was my point. Other than STS
51-L (partial recovery), an ET has never been recovered and only a few have
ever been photographed. None of that photography was at a resolution that
would detect small tank leaks which leaves leak detection up to hydrogen
depletion sensors coupled with ullage pressure deviations.

--

Daniel
Mount Charleston, not Charleston SC


  #63  
Old March 6th 05, 08:54 PM
Charleston
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"OM" om@our_blessed_lazy_ass_of_the OM God_holy ****_research_facility.org
wrote:

1. You, nor anyone else here for that matter, have expressed an interest
in
my genuine offer to share telemetry which I described as "nauseating".


...That's because nobody wants to see your father's kiddie porn.
Nobody normal, that is.


Which would rule you out of course.

Daniel


  #64  
Old March 6th 05, 08:59 PM
Scott Lowther
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Charleston wrote:

"Herb Schaltegger" wrote:


"Charleston" wrote:


Facts:

1. You, nor anyone else here for that matter, have expressed an interest
in
my genuine offer to share telemetry which I described as "nauseating". I
did not even get a simple question back as to which telemetry I was
referring.


Perhaps if you posted excerpts (here directly, or via a link to
something specific on your site) along with an analysis of any
significance (e.g., why it is "nauseating"), you might draw some
serious interest.



The data would not fit here well and any subsequent posts would make it
become difficult to read. I will post the raw "as received" STS 51-L SRB
chamber pressure data in its entirety on my website
www.challengerdisaster.info tonight.


I will look forward to that. Since I'll be responsible for analyzing the
ballistics of the two SRB's from the forthcoming launch in May, it
should be interesting to see what you have... and how you interpret it.
  #65  
Old March 6th 05, 11:17 PM
Charleston
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"Scott Lowther" wrote:
Charleston wrote:


The data would not fit here well and any subsequent posts would make it
become difficult to read. I will post the raw "as received" STS 51-L SRB
chamber pressure data in its entirety on my website
www.challengerdisaster.info tonight.


I will look forward to that. Since I'll be responsible for analyzing the
ballistics of the two SRB's from the forthcoming launch in May, it should
be interesting to see what you have... and how you interpret it.


Great. It is now posted. Of course I look forward to your insight as well.

www.challengerdisaster.info

Daniel


  #66  
Old March 6th 05, 11:30 PM
Pat Flannery
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Scott Lowther wrote:


I will look forward to that. Since I'll be responsible for analyzing
the ballistics of the two SRB's from the forthcoming launch in May, it
should be interesting to see what you have... and how you interpret it.



Did they fix those bolt catchers? That was a major accident waiting to
happen.

Pat
  #67  
Old March 7th 05, 01:14 AM
Scott Lowther
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Pat Flannery wrote:



Scott Lowther wrote:


I will look forward to that. Since I'll be responsible for analyzing
the ballistics of the two SRB's from the forthcoming launch in May,
it should be interesting to see what you have... and how you
interpret it.




Did they fix those bolt catchers?



Couldn't tell ta... that was on the ET side. I *believe* they did so,
however.

I couldn't get anyone at UTC to take my idea seriously of putting GPS
guided booster rockets on the bolts, and have them, blast away after
severance... sigh...
  #68  
Old March 7th 05, 01:34 AM
Scott Lowther
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Charleston wrote:

"Scott Lowther" wrote:


Charleston wrote:





The data would not fit here well and any subsequent posts would make it
become difficult to read. I will post the raw "as received" STS 51-L SRB
chamber pressure data in its entirety on my website
www.challengerdisaster.info tonight.


I will look forward to that. Since I'll be responsible for analyzing the
ballistics of the two SRB's from the forthcoming launch in May, it should
be interesting to see what you have... and how you interpret it.



Great. It is now posted. Of course I look forward to your insight as well.


At first glance, after converting the date and time into something Excel
can use and restting T0 to be ignition, the pressure dats looks pretty
normal up until 59 seconds or so, when the right-hand transducers all
show a decrease in chamber pressure compared to the left handers. Not
overly surprising given that there was a hole in the side of the
booster, and total port area was increased.

I can compare this data to recent RSRM motor firings no sweat, but
performance has changed a little since 86. But to first order the
overall pressure trace up until T+59 seconds looks about right.

Neither the spread in readigns from Xducer to Xducer not the very jagged
appearance of the data are unusual. The data rate from the Xducers is
achingly slow to this date
  #69  
Old March 7th 05, 02:33 AM
Pat Flannery
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Scott Lowther wrote:


Did they fix those bolt catchers?




Couldn't tell ta... that was on the ET side. I *believe* they did so,
however.



I checked, they fixed them:
http://www.dancewithshadows.com/tech...ery-launch.asp

"March 3, 2005


Space Shuttle Discovery: External tank mated to rocket boosters

NASA marked a major step in assembling Space Shuttle Discovery for its
Return to Flight mission, as workers successfully mated the redesigned
External Tank and twin Solid Rocket Boosters. The fuel tank and booster
rockets will help launch Space Shuttle Discovery. The External Tank was
lifted by a giant crane and joined to the already stacked boosters in
the 52-story Vehicle Assembly Building at NASA's Kennedy Space Center in
Florida.

The external tank is the largest element of the Space Shuttle system,
which also includes the orbiter, main engines and rocket boosters. It
measures 27.6 feet wide and 154 feet tall. Despite the tank's size, the
aluminum skin covering it is only one eighth of an inch thick in most
areas. Yet it still withstands more than 6.5 million pounds of thrust
during liftoff and ascent. The tank is the only Shuttle component that
cannot be reused.

Following integration and final checkout of the tank with the Solid
Rocket Boosters, Discovery will join its propulsion components in the
Vehicle Assembly Building. Discovery will roll over from the Orbiter
Processing Facility later this month, marking the end of Return to
Flight processing. The orbiter will be attached to the stack in the
Vehicle Assembly Building .

The external tank will fly with several modifications. They include two
new forward bipod heaters at the forward attach fittings that connect
the tank to the orbiter. NASA and Lockheed Martin Space Systems Co.
spent nearly two years modifying the tank to make it safer. During the
tank-booster mating, the left and right boosters are bolted to the tank
at both the top and tail ends. At the forward end, a vertical bolt
mechanism attaches each booster to the tank.

After the Space Shuttle Discovery launch, approximately two minutes
after lift-off, the boosters will separate from the external tank, when
pyrotechnic devices fire to break the 25-inch, 62-pound steel bolts. One
half of the bolt is caught in canister-like bolt catchers located on the
tank; the other half remains with the boosters.

Discovery will be the first flight with a modified bolt catcher. It was
upgraded from a two-piece welded design to a one-piece, machine-made
design. By eliminating the weld, the new bolt catcher is structurally
stronger than the original.

Prior to Discovery joining the stack, final closeouts on the external
tank will include attaching the new bolt catcher and electrical cable
connections. An aerodynamic fairing and the bi-pod struts, the attach
points for the nose of the orbiter to the tank, will also be installed."

God knows how many times they dodged the bullet with those things; if a
piece of urethane foam can fatally damage the TPS, I'd hate to think
what a 30 pound piece of steel would do.


I couldn't get anyone at UTC to take my idea seriously of putting GPS
guided booster rockets on the bolts, and have them, blast away after
severance... sigh...



Theoretically they are supposed to stay attached to the vehicle, and not
fall off at all- I still shake my head when they found out that they
were coming free, and the Cape radar operators finally found out what
those odd things were that were showing up on radar when the SRBs
separated. You would have thought they would have mentioned that to
someone earlier on. :-\

Pat
  #70  
Old March 7th 05, 03:49 AM
Charleston
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"Scott Lowther" wrote:
Charleston wrote:
"Scott Lowther" wrote:
Charleston wrote:


The data would not fit here well and any subsequent posts would make it
become difficult to read. I will post the raw "as received" STS 51-L
SRB chamber pressure data in its entirety on my website
www.challengerdisaster.info tonight.

I will look forward to that. Since I'll be responsible for analyzing the
ballistics of the two SRB's from the forthcoming launch in May, it should
be interesting to see what you have... and how you interpret it.


Great. It is now posted. Of course I look forward to your insight as
well.

At first glance, after converting the date and time into something Excel
can use and restting T0 to be ignition, the pressure dats looks pretty
normal up until 59 seconds or so, when the right-hand transducers all show
a decrease in chamber pressure compared to the left handers. Not overly
surprising given that there was a hole in the side of the booster, and
total port area was increased.


I put the data up as I received it, adjusting the headers slightly for
clarity, so that anyone familiar with same would recognize that I have
presented it the way NASA first saw it 19 years ago. I too, have set it up
in an Excel spreadsheet to examine it in a number of meaningful ways.

From your read of the data what is the data rate for xducers 1302 and 2302?
How about the other two sets of xducers? They do have data rates IIRC.

I can compare this data to recent RSRM motor firings no sweat, but
performance has changed a little since 86.


By all means please do.

But to first order the overall pressure trace up until T+59 seconds looks
about right.


Following the redesign of the SRBs a higher thrust differential between the
two boosters was allowed. The data I posted reflects rather sensitive
instrumentation with three significant figures right? Given the resolution
of the xducers at 1/1000 of a PSI, what do you suppose the actual accuracy
is in PSI? Don't bother looking in the PC report, you will not find it
anywhere in any of the five volumes. We can come back to the 59 second
issue later. It might be helpful.

Neither the spread in readigns from Xducer to Xducer not the very jagged
appearance of the data are unusual.


Not back then, I must agree. Does that make it okay during steady state
burn? Today I sort of doubt you have those spreads between the xducers.
They have been under configuration control *since* STS 51-L. NASA is aware
of some relatively small perturbations in the pressure from reading to
reading, sure.

The data rate from the Xducers is achingly slow to this date


Quality high rate data is three things:

1. Expensive
2. Heavy
3. Processor intensive

Nevertheless, if one is going to stake a report on data like that to which I
have referred, it should be honestly presented, accurate within a tolerance
that makes the data truly relevant, and it should mate with applicable
photographic and related data measurements.

Now one more thing, looking at the data, what interpretive value would you
place on it during the first second following T= 0?

Daniel
Mount Charleston, not Charleston SC
www.challengerdisaster.info




 




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