NASA Astronaut on Columbia Repair (and others)

"columbiaaccidentinvestigation"
wrote in message
oups.com...

Open sharing of information is crucial to improving everybody's
understanding of the universe around us.

Even more crucial is the *acceptance of information that conflicts with your
beliefs*. Hint hint.

OM wrote:




Open sharing of information is crucial to improving everybody's
understanding of the universe around us.



...Fee. Fie. Foe. Fum. I *do* smell the stench of a Znkfba scum.


Even the posting name is something you'd expect isn't it?
The first time I saw that name, you-know-who came to mind immediately.

Pat

They had several months to do some tests. But they never published
what they did. They have this test facility and they were ordered
by Gehman to do it. So they did something. And no action in such
a facility without a report. This reports are somewhere.

No, that is incorrect. The CAIB asked NASA to perform the In-Flight
Options Assessment in mid-April 2003 and to deliver it in 3 weeks. In
that timeframe no material testing was possible, only analysis. The

I would expect first results of material tests within 3 days(!)
They had the facility and test rigs for the RCC they already used.
But there was no need for an test because they already had the data
we are talking about. NASA had to know for +30 years how a crack in
the RCC will behave during reentry. So the oxidation at the hole of
Columbia never was an issue because they did know it was none:


http://www.ksc.nasa.gov/columbia/caib0318hearing.htm

Columbia Accident Investigation Board Public Hearing Tuesday,
March 18, 2003

MR. MADDEN: I'm Chris Madden. I'm deputy branch chief of the Thermal
Design Branch in the Johnson Space Center. My background includes
thermoanalysis of TPS systems for reentry spacecraft. Some of that's
included analysis of shuttle flight anomalies and other computation
roles on the shuttle.

...
DR. WIDNALL: Wait a minute. I've got a question. The material that
John is talking about, if the leading edge is damaged, is carbon.
Carbon reacts chemically with the available oxygen and that will,
in fact, release ...
...
MR. MADDEN: An uncoated carbon panel û I think that would have been
briefed on this û an uncoated carbon panel will oxidize because the
carbon's going to react with the oxygen. And it's quite rapid. But
as far as surviving a mission, I think, even though you get some
damage, in most cases you don't eat through the entire thickness of
the carbon. There's catalysis and oxidation on top of each other.
...
MR. MADDEN: We performed analysis for the investigation on panels
with existing holes and how fast they grow and how fast they eat
away at the spar.

His wording may allow you to interpret this "analysis" as a theoretical
one without experiments. Maybe, but they had the test befo

CAIB Vol 1:

Wing Leading Edge Damage

The risk of micrometeoroid or debris damage to the RCC panels has been
evaluated several times. Hypervelocity impact testing, using nylon,
glass, and aluminum projectiles, as well as low-velocity impact testing
with ice, aluminum, steel, and lead projectiles, resulted in the addition
of a 0.03- to 0.06-inch-thick layer of Nextel-440 fabric between the
Inconel foil and Cerachrome insulation. Analysis of the design change
predicts that the Orbiter could survive re-entry with a quarter-inch
diameter hole in the lower surfaces of RCC panels 8 through 10 or with
a one-inch hole in the rest of the RCC panels.

This reffers to a time before CAIB. The last sentence is only possible
if they did extensive testing in the arcjet facility. Together with
the other statments by Madden it rules out any importance of the
oxidation at the crack surface in the Columbia case. The CAIB conclusions
still stands.

You got your idea of the overlooked issue of RCC oxidation after you
heard something and presented your own conclusions from it here some
months ago. I think its now time to let it rest before it gots one of
the many Columbia myths on Usenet.


One other note I got. Seems you (I bet not only you) think an numerical
analysis is faster or more easy then an experiment. In this casew its the
other way around. If you already have a test facility (like NASAs arcjet
one) its the best and fastest way to test it instead to try to calc it.
Except of course if you already tested something similar and only have
to interpolate it. Otherwise a pure nummerical analysis of such a complex
problem takes a lot of effort to build and evaluate the model and the
software. I did several aerothermal analyses (not hypersonic). In one
case I had a lot of experimental data to base the model and the software
on and it was all turbulent BL. It was a fair mater of a few weeks. After
the thing was build the in real measurments proved the predictions as ok.
In another case there was only extrapolated data and nowhere any comperable
experimental data. The calculations lasted weeks with single simulations
more then a day. The crucial problem showed up to be an hard to predict
laminar/turbulent transition. After all I abondoned the calc and suggested
a way to enforce turbulent BL from the beginning. I could prove that it
would certainly solve the thermal problem and get the vehicle on the
safe side. After I read about the origine of the Shuttle PAL ramp I
remembered it. It seems they did the same way. Sometimes its usefule
to skip advanced analysis for the straight real thing. The result may not
be perfection, but a certain way to get it safely work.


Ok, let us look in this example. Show me the source. I`m very
interested in the details of this test.

I'm sure you are. But as far as I know, the presentation is unpublished,
and I have no intention of jumping through the export-control hoops it
would take to publish it.

If this guys hide it behind arms trade regulations better you no longer
trust em in all things. Maybe it was a presentation intended to mind
wash some people. So they get out and spread rumors some NASA guye
like to read here and elesewhere. Phil Chien got such "sources" too
I think. At least I doubt that he made it up by himself. PR is a game
with many tricks and some guys at NASA belong to the best.



Second Part: Early BLT at Columbia by RCC hole?


4. on other missions Columbia had several early BL trips without
serious damage or without any damage at all.

The earliest of those BL trips was around Mach 19, more than halfway
through the peak heating period. I'm talking about a BL that goes
turbulent from the *very beginning*, at Mach 25.

I have not checked this. But as others have pointed out, the heat load
at Mach 25 is rather low.

Irrelevant. What's relevant is that at Mach 25, the entire period of
peak heating is in the future. By Mach 19 a great deal of it is in the
past and the total heating load from there to the end of the peak
heating period will be far less.

Well, there never was a very early (M 25) BL trip and it seems
questionable whether such an early transition would be possible.
The M 19 BLTs were not caused by surface roughness but probably
by sticking out gap fillers. It not only happened to Columbia
but others too. I think such a gap filler until it melts away
is the worst flow obstacle on could think of. If it was unable
to trigger a M 25 BLT what else can do it? It seems at M 25 the
flow condition is to far way from the transitional Reynolds area
so BLT is no issue.


2. there was no evidence of BL trip related damage by CAIB, it
all developed at the RCC

There was no evidence *remaining*. The RCC panel in question eroded away
quickly; *none* of its lower surface was recovered. Likewise the lower
surface of the wing behind it. The CAIB noted there was very little
debris recovered from the left wing.

The remaining evidence was extern the shuttle. The telemetry showed
no indication of BL trip. The CAIB reconstruction of the destruction
process explained all evidence (even the lost bright glowing tiles)
by events just behind the leading edge.

Now I found the discussion of the telemetry whether Columbia had
an "Asymmetric Boundary Layer Transition". Asymmetric because only
one wing was in question. Its not in the CAIB report but he

http://www.ksc.nasa.gov/columbia/caib0318hearing.htm
Columbia Accident Investigation Board Public Hearing
Tuesday, March 18, 2003

This morning we have Mr. Stephen Labbe, the chief of the Applied
Aeroscience and Computational Fluid Dynamics Branch of NASA;

MR. LABBE:... The one thing I would like to point out is that the
results û we see initially a negative roll and a negative yaw, and
there's been a lot of discussion about asymmetric boundary layer
transition. When you experience that on the orbiter, these two
increments will have opposite sines. So if you have positive yaw,
you'll have negative roll or vice versa. We saw the same sine on
this. This indicates to me that whatever was happening early on is
not asymmetric boundary layer transition; it's some damage. ...

I think with that the question of early BLT on Columbia is closed.
Now, why didnt the CAIB mentioned the surface roughness of the RCC
hole as a BLT issue? The hole would be a big obstacle, biger then
anything remaining from an in orbit repair. As the CAIB looked in
about all thinkable issues, it may be that it never was one for the
experts.

I thought about. Maybe the surface flow at the RCC underside is
unimportant for the BLT. In front of the RCC is the bow shock,
what deflects some of the incomming flow. The wing is inclined
by 40 degree. Therefore the wing below the RCC gets part of the
flow from the free space in front of the shuttle. In other words,
at the middle of the wing near the wheel bay only a fraction of
the BL mass flow there had passed the RCC underside. I`m not sure
on that but it may one explanation.

Anyway, as Columbia had no very early BLT, any reasonable RCC repair
would not face it too.

--
JRF


## CrossPoint v3.12d R ##

Derek Lyons wrote:

My criticism is not of his behavior at the time, but that the picture
he paints of himself today and his behavior at the time do not agree
with each other....

What likely caught the imagination of IEEE, AAAS, AIAA and others who
have recognized Roger Boisjoly was the combination of three factors:

- the Challenger incident was a very high profile event

- he was candid and forthcoming when called upon to testify by the
Rogers Commission

- unlike other colleagues at MT who actively opposed the launch
*after* the infamous telecon between NASA and MT, e.g., Allan
McDonald, he had generated an internal paper trail concerning the
seriousness of the situation that began over half a year before the
incident

The latter point is the most important. Had Boisjoly and co. only
become concerned a few days before the launch, interest in their
predicament would have been less intense. The existence of a paper
trail with forceful and unambiguous warnings over a period of months
made the difference.

To me, recognizing Boisjoly and his colleagues is a positive thing
because it serves as a reminder to everyone that any of us could be
caught in a similar situation. As engineers, we have a duty to be aware
and to warn, repeatedly if necessary. As managers, we have a duty to
listen to our staff who, by virtue of having more direct contact with an
issue may have a better sense of its seriousness.

There is a tendency, especially in Government Aerospace, I'm told (by
former colleagues), to view engineers as commodities and to reserve
creativity and judgement for managers and above. The Boisjoly case
reminds us that such a tendency should be resisted.

You're right: There are many cases where subordinates rail against a
management plan or decision but are not fully aware of all the factors
that led to it. These don't fall into the same category.

You're also right: It would be most useful to have a sense of how many
overcautious warnings management had to deal with. Enough of those will
dull anyone to a legitimate warning. Unfortunately, collecting such
data would be very difficult so I'm not holding my breath :-\

--
Dave Michelson

Dave Michelson wrote:"You're also right: It would be most useful to
have a sense of how many overcautious warnings management had to deal
with. Enough of those will dull anyone to a legitimate warning.
Unfortunately, collecting such data would be very difficult so I'm not
holding my breath :-\"

The human error (not accounted for in shuttle risk analysis) of
deciding to launch in the cold weather on the morning of jan 28, 1986,
was one that could have been avoided if the nasa managers that
overruled Roger Boisjoly and his colleagues efforts to hold off the
launch of challenger, would have taken the time to evaluate the srb
burn though data from the prior flight of sts-61c, and correlate it to
the effects of cold weather on the srb joint o-ring seal resiliency.
The same communication problems cited by the rogers commission, were
cited by the Columbia accident investigation board, and therefore, just
maybe if the changes roger boisjoly recommended to congressional
subcommittee of space and science technology of 1991, possibly the
Columbia tragedy would not have occurred. Roger Boijolys point to
bring about a change in nasa policies, was to make upper management
criminally responsible for their decisions (if found to be negligent),
as to prevent non-ethical forces influencing decisions, such as what
happened in the case of management choosing to launch challenger the
morning of jan 28 1986, in spite of recommendations not to launch by
Boisjoly and his colleagues.

Now implementing the recommendations contained in the diaz report to
the caib, in conjunction with a full quantitative risk assessment of
the shuttle system would provide nasa managers with the communication
structure, information, and technology to manage and understand the
technical input from others up and down the decision making process in
operating the shuttle safely within it's capabilities throughout the
fleets retirement process. The tension that is mentioned above with
respect to management, and engineers can be seen in many industries as
schedule pressures are pitted against safety, but the caib's
recommendations to establish an independent technical authority
demonstrate the communication problems that existed in nasa pre
challenger tragedy, are still existent in nasa post Columbia tragedy.


Schedule pressures
Caib report vol 1 page 131, col 1, par 10
"Chapter 6, Decision Making at Nasa
Recomedations
6.2 SCHEDULE PRESSURE
Countdown to Space Station "Core Complete:" A Workforce Under
Pressure
During the course of this investigation, the Board received several
unsolicited comments from NASA personnel regard-ing pressure to meet a
schedule. These comments all con-cerned a date, more than a year after
the launch of Columbia, that seemed etched in stone: February 19, 2004,
the sched-uled launch date of STS-120. This flight was a milestone in
the minds of NASA management since it would carry a sec-tion of the
International Space Station called "Node 2." This would configure
the International Space Station to its "U.S. Core Complete" status.


Independent Technical Authority
Caib report vol 1 page 227 col 1
"Chapter 11 Recommendations
Organization
R7.5-1 Establish an independent Technical Engineering Authority that is
responsible for technical requirements and all waivers to them, and
will build a disciplined, systematic approach to identifying,
analyzing, and controlling hazards throughout the life cycle of the
Shuttle System. The independent technical authority does the fol-lowing
as a minimum:
· Develop and maintain technical standards for all Space Shuttle
Program projects and elements
· Be the sole waiver-granting authority for all technical standards
· Conduct trend and risk analysis at the sub-system, system, and
enterprise levels
· Own the failure mode, effects analysis and hazard reporting systems

· Conduct integrated hazard analysis
· Decide what is and is not an anomalous event
· Independently verify launch readiness
· Approve the provisions of the recertifica-tion program called for
in Recommendation R9.1-1.
The Technical Engineering Authority should be funded directly from NASA
Headquarters, and should have no connection to or responsibility for
schedule or program cost.
R7.5-2 NASA Headquarters Office of Safety and Mis-sion Assurance should
have direct line authority over the entire Space Shuttle Program safety
organization and should be independently re-sourced.
R7.5-3 Reorganize the Space Shuttle Integration Office to make it
capable of integrating all elements of the Space Shuttle Program,
including the Or-biter."


Open sharing of information is crucial to improving everybody's
understanding of the universe around us.
Tom



Dave Michelson wrote:
Derek Lyons wrote:

My criticism is not of his behavior at the time, but that the picture
he paints of himself today and his behavior at the time do not agree
with each other....

What likely caught the imagination of IEEE, AAAS, AIAA and others who
have recognized Roger Boisjoly was the combination of three factors:

- the Challenger incident was a very high profile event

- he was candid and forthcoming when called upon to testify by the
Rogers Commission

- unlike other colleagues at MT who actively opposed the launch
*after* the infamous telecon between NASA and MT, e.g., Allan
McDonald, he had generated an internal paper trail concerning the
seriousness of the situation that began over half a year before the
incident

The latter point is the most important. Had Boisjoly and co. only
become concerned a few days before the launch, interest in their
predicament would have been less intense. The existence of a paper
trail with forceful and unambiguous warnings over a period of months
made the difference.

To me, recognizing Boisjoly and his colleagues is a positive thing
because it serves as a reminder to everyone that any of us could be
caught in a similar situation. As engineers, we have a duty to be aware
and to warn, repeatedly if necessary. As managers, we have a duty to
listen to our staff who, by virtue of having more direct contact with an
issue may have a better sense of its seriousness.

There is a tendency, especially in Government Aerospace, I'm told (by
former colleagues), to view engineers as commodities and to reserve
creativity and judgement for managers and above. The Boisjoly case
reminds us that such a tendency should be resisted.

You're right: There are many cases where subordinates rail against a
management plan or decision but are not fully aware of all the factors
that led to it. These don't fall into the same category.

You're also right: It would be most useful to have a sense of how many
overcautious warnings management had to deal with. Enough of those will
dull anyone to a legitimate warning. Unfortunately, collecting such
data would be very difficult so I'm not holding my breath :-\

--
Dave Michelson

Scott Hedrick wrote:
"columbiaaccidentinvestigation"
wrote in message
oups.com...

Open sharing of information is crucial to improving everybody's
understanding of the universe around us.

Even more crucial is the *acceptance of information that conflicts with your
beliefs*. Hint hint."

Interesting statement scott, bust as the rogers commission stated
unequivocally "Under the terms of the FRR Policy Directive, such
damage would appear to require discussion: "the scope of the review
should cover status and issues in areas such as . . . prior flight
anomalies (*1), when referring to the previous flights (sts-61c) srbs
evaluation (*2) which clearly showed a burn through problem, but
because of attempting to meet schedule demands the time was not taken
by mission managers to evalutatef the effects of cold weather on the
srb joint o-ring seal resiliency, when making the tragic go for launch
decision in the cold weather the morning of jan 28, 1986.

Now implementing the recommendations contained in the diaz report to
the caib, in conjunction with a full quantitative risk assessment of
the shuttle system would provide nasa managers with the communication
structure, information, and technology to manage and understand the
technical input from others up and down the decision making process in
operating the shuttle safely within it's capabilities throughout the
fleets retirement process.

(*1)
http://www.gpoaccess.gov/challenger/64_420b.pdf
page (26 pdf) or 208 in the report
Post-flight disassembly of STS 61-C SRB hardware following its launch
on January 12 revealed that erosion of the primary O-ring had occurred
in the aft field joint of the left motor. Hot gas had also bypassed the
primary seal in the left nozzle joint. Erosion of the primary seal had
also occurred in the nozzle joint of the right motor.6 Under the terms
of the FRR Policy Directive, such damage would appear to require
discussion: "the scope of the review should cover status and issues
in areas such as . . . prior flight anomalies. . . ."
lies. . . ."

(*2)
And the sts-61c srb evaluation stated:
http://ntrs.nasa.gov/archive/nasa/ca...992075284..pdf
NSTS-22301, page 4
"SOLID ROCKET BOOSTER
The STS 61-C flight utilized lightweight solid rocket motor (SRM)
cases. SRM
propulsion performance was normal and within specification limits, with
propellant burn rates for both SRM's near predicted values. Solid
rocket booster (SRB) thrust differentials were within specification
throughout the flight....

A postflight evaluation of the SRM structure to determine the extent of
damage
revealed the following significant items:
a. A gas path was noted at the 154-degree position of the aft field
joint of the left S_M. Soot was found from the 140-degree to the
178-degree position, and soot was found in the primary groove from the
68-degree to the 183-degree (115 degrees arc) position. C-ring
damagewas noted at the 154-degree position with a maximumerosion depth
of 0.00_ inch and erosion length of 3.5 inches. The 0-ring was affected
by heat over a 14-inch length in this area.
b. A gas path was found from the 273.6-degree to the 309.6-degree (36
degrees arc) position of the left S_Mnozzle joint. Soot was found in
the primary 0-ring groove over the entire 360-degree circumference. A
potential impingement point was located at the 302.4-degree point;
however, no 0-ring damage was found.
c. A gas path was found at the 162-degree point with soot in the
primary 0-ring groove from the lOS-degree to the 220-degree (112
degrees arc) point on the right SRM nozzle joint. 0-ring damage was
found at the 162-degree point with the maximum erosion depth being
0.011 inch and the erosion length being 8 inches. The 0-rlng was
affected by heat over a 26-1nch length in this area.
d. A gas path was found on the outer surface of the igniter at the
130-degree point of the left SRM. Soot was found on the aft side of the
outer Gaskoseal, approaching the primary sea! over a 70-degree arc (130
to 200 degrees), and on the outer edge of the inner Gasko seal over a
130-degree arc (ii0 to 240 degrees), however, no seal damage was found.
e. A gas path was found on the outer surface of the igniter at the
250-degree point of the right S_. Soot was found on the inside edge of
the outer Gasko seal over the entire 360-degree circumference, however,
it did not progress beyond the edge of the seal. There was a slight
discoloration of the metal on both sides of the seal over the entire
360-degree circumference."

Probabilistic Risk Analysis for the NASA Space Shuttle:
A Brief History and Current Work by Elisabeth Paté-Cornell, Stanford
University,
and Robin Dillon, Virginia Tech Submitted for publication in
Reliability Engineering and System Safety April, 2000

Schedule pressures
Caib report vol 1 page 131, col 1, par 10
"Chapter 6, Decision Making at Nasa
Recomedations
6.2 SCHEDULE PRESSURE
Countdown to Space Station "Core Complete:" A Workforce Under
Pressure
During the course of this investigation, the Board received several
unsolicited comments from NASA personnel regard-ing pressure to meet a
schedule. These comments all con-cerned a date, more than a year after
the launch of Columbia, that seemed etched in stone: February 19, 2004,
the sched-uled launch date of STS-120. This flight was a milestone in
the minds of NASA management since it would carry a sec-tion of the
International Space Station called "Node 2." This would configure
the International Space Station to its "U.S. Core Complete" status.


Independent Technical Authority
Caib report vol 1 page 227 col 1
"Chapter 11 Recommendations
Organization
R7.5-1 Establish an independent Technical Engineering Authority that is
responsible for technical requirements and all waivers to them, and
will build a disciplined, systematic approach to identifying,
analyzing, and controlling hazards throughout the life cycle of the
Shuttle System. The independent technical authority does the fol-lowing
as a minimum:
· Develop and maintain technical standards for all Space Shuttle
Program projects and elements
· Be the sole waiver-granting authority for all technical standards
· Conduct trend and risk analysis at the sub-system, system, and
enterprise levels
· Own the failure mode, effects analysis and hazard reporting systems

· Conduct integrated hazard analysis
· Decide what is and is not an anomalous event
· Independently verify launch readiness
· Approve the provisions of the recertifica-tion program called for
in Recommendation R9.1-1.
The Technical Engineering Authority should be funded directly from NASA
Headquarters, and should have no connection to or responsibility for
schedule or program cost.
R7.5-2 NASA Headquarters Office of Safety and Mis-sion Assurance should
have direct line authority over the entire Space Shuttle Program safety
organization and should be independently re-sourced.
R7.5-3 Reorganize the Space Shuttle Integration Office to make it
capable of integrating all elements of the Space Shuttle Program,
including the Or-biter."


Open sharing of information is crucial to improving everybody's
understanding of the universe around us.
Tom

On Sat, 18 Nov 2006 08:50:55 -0500, "Scott Hedrick"
wrote:

"columbiaaccidentinvestigation"
wrote in message
roups.com...

Open sharing of information is crucial to improving everybody's
understanding of the universe around us.

Even more crucial is the *acceptance of information that conflicts with your
beliefs*. Hint hint.

....If it smells like a Znkfba, and trolls like a Znkfba, it probably
*is* a Znkfba.

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

OM wrote:
On Sat, 18 Nov 2006 08:50:55 -0500, "Scott Hedrick"
wrote:

"columbiaaccidentinvestigation"
wrote in message
roups.com...

Open sharing of information is crucial to improving everybody's
understanding of the universe around us.

Even more crucial is the *acceptance of information that conflicts with your
beliefs*. Hint hint.

...If it smells like a Znkfba, and trolls like a Znkfba, it probably
*is* a Znkfba."


Interesting statement om, (but what really stinks is the lure you're
trolling with so go troll in some other waters maybe you'll get some
bites, not here now back to the facts), but as the rogers commission
stated unequivocally "Under the terms of the FRR Policy Directive,
such damage would appear to require discussion: "the scope of the
review should cover status and issues in areas such as . . . prior
flight anomalies" (*1), when referring to the previous flights
(sts-61c) srbs evaluation (*2) which clearly showed a burn through
problem, but because of attempting to meet schedule demands the time
was not taken by mission managers to make logical correlation of with
the effects of cold weather on the srb joint o-ring seal resiliency,
when making a go for launch decision in the cold weather the morning of
jan 28, 1986.

Now implementing the recommendations contained in the diaz report to
the caib, in conjunction with a full quantitative risk assessment of
the shuttle system would provide nasa managers with the communication
structure, information, and technology to manage and understand the
technical input from others up and down the decision making process in
operating the shuttle safely within it's capabilities throughout the
fleets retirement process.

(*1)
http://www.gpoaccess.gov/challenger/64_420b.pdf
page (26 pdf) or 208 in the report
Post-flight disassembly of STS 61-C SRB hardware following its launch
on January 12 revealed that erosion of the primary O-ring had occurred
in the aft field joint of the left motor. Hot gas had also bypassed the
primary seal in the left nozzle joint. Erosion of the primary seal had
also occurred in the nozzle joint of the right motor.6 Under the terms
of the FRR Policy Directive, such damage would appear to require
discussion: "the scope of the review should cover status and issues
in areas such as . . . prior flight anomalies. . . ."
lies. . . ."

(*2)
And the sts-61c srb evaluation stated:
http://ntrs.nasa.gov/archive/nasa/ca...992075284..pdf
NSTS-22301, page 4
"SOLID ROCKET BOOSTER
The STS 61-C flight utilized lightweight solid rocket motor (SRM)
cases. SRM
propulsion performance was normal and within specification limits, with
propellant burn rates for both SRM's near predicted values. Solid
rocket booster (SRB) thrust differentials were within specification
throughout the flight....

A postflight evaluation of the SRM structure to determine the extent of
damage
revealed the following significant items:
a. A gas path was noted at the 154-degree position of the aft field
joint of the left S_M. Soot was found from the 140-degree to the
178-degree position, and soot was found in the primary groove from the
68-degree to the 183-degree (115 degrees arc) position. C-ring
damagewas noted at the 154-degree position with a maximumerosion depth
of 0.00_ inch and erosion length of 3.5 inches. The 0-ring was affected
by heat over a 14-inch length in this area.
b. A gas path was found from the 273.6-degree to the 309.6-degree (36
degrees arc) position of the left S_Mnozzle joint. Soot was found in
the primary 0-ring groove over the entire 360-degree circumference. A
potential impingement point was located at the 302.4-degree point;
however, no 0-ring damage was found.
c. A gas path was found at the 162-degree point with soot in the
primary 0-ring groove from the lOS-degree to the 220-degree (112
degrees arc) point on the right SRM nozzle joint. 0-ring damage was
found at the 162-degree point with the maximum erosion depth being
0.011 inch and the erosion length being 8 inches. The 0-rlng was
affected by heat over a 26-1nch length in this area.
d. A gas path was found on the outer surface of the igniter at the
130-degree point of the left SRM. Soot was found on the aft side of the
outer Gaskoseal, approaching the primary sea! over a 70-degree arc (130
to 200 degrees), and on the outer edge of the inner Gasko seal over a
130-degree arc (ii0 to 240 degrees), however, no seal damage was found.
e. A gas path was found on the outer surface of the igniter at the
250-degree point of the right S_. Soot was found on the inside edge of
the outer Gasko seal over the entire 360-degree circumference, however,
it did not progress beyond the edge of the seal. There was a slight
discoloration of the metal on both sides of the seal over the entire
360-degree circumference."

Probabilistic Risk Analysis for the NASA Space Shuttle:
A Brief History and Current Work by Elisabeth Paté-Cornell, Stanford
University,
and Robin Dillon, Virginia Tech Submitted for publication in
Reliability Engineering and System Safety April, 2000

Schedule pressures
Caib report vol 1 page 131, col 1, par 10
"Chapter 6, Decision Making at Nasa
Recomedations
6.2 SCHEDULE PRESSURE
Countdown to Space Station "Core Complete:" A Workforce Under
Pressure
During the course of this investigation, the Board received several
unsolicited comments from NASA personnel regard-ing pressure to meet a
schedule. These comments all con-cerned a date, more than a year after
the launch of Columbia, that seemed etched in stone: February 19, 2004,
the sched-uled launch date of STS-120. This flight was a milestone in
the minds of NASA management since it would carry a sec-tion of the
International Space Station called "Node 2." This would configure
the International Space Station to its "U.S. Core Complete" status.


Independent Technical Authority
Caib report vol 1 page 227 col 1
"Chapter 11 Recommendations
Organization
R7.5-1 Establish an independent Technical Engineering Authority that is
responsible for technical requirements and all waivers to them, and
will build a disciplined, systematic approach to identifying,
analyzing, and controlling hazards throughout the life cycle of the
Shuttle System. The independent technical authority does the fol-lowing
as a minimum:
· Develop and maintain technical standards for all Space Shuttle
Program projects and elements
· Be the sole waiver-granting authority for all technical standards
· Conduct trend and risk analysis at the sub-system, system, and
enterprise levels
· Own the failure mode, effects analysis and hazard reporting systems

· Conduct integrated hazard analysis
· Decide what is and is not an anomalous event
· Independently verify launch readiness
· Approve the provisions of the recertifica-tion program called for
in Recommendation R9.1-1.
The Technical Engineering Authority should be funded directly from NASA
Headquarters, and should have no connection to or responsibility for
schedule or program cost.
R7.5-2 NASA Headquarters Office of Safety and Mis-sion Assurance should
have direct line authority over the entire Space Shuttle Program safety
organization and should be independently re-sourced.
R7.5-3 Reorganize the Space Shuttle Integration Office to make it
capable of integrating all elements of the Space Shuttle Program,
including the Or-biter."


Open sharing of information is crucial to improving everybody's
understanding of the universe around us.
Tom

columbiaaccidentinvestigation wrote:

OM wrote:


On S


...If it smells like a Znkfba, and trolls like a Znkfba, it probably
*is* a Znkfba."




Interesting statement om, (but what really stinks is the lure you're
trolling with so go troll in some other waters maybe you'll get some
bites, not here now back to the facts)



Wordy little blowhard, aren't you?
(plonk)

Pat

On Sun, 19 Nov 2006 00:15:00 +0200, SENECA wrote:

I thought about. Maybe the surface flow at the RCC underside is
unimportant for the BLT. In front of the RCC is the bow shock,
what deflects some of the incomming flow. The wing is inclined
by 40 degree. Therefore the wing below the RCC gets part of the
flow from the free space in front of the shuttle. In other words,
at the middle of the wing near the wheel bay only a fraction of
the BL mass flow there had passed the RCC underside. I`m not sure
on that but it may one explanation.

I posted this on the flow on the bottom side of the Orbiter some time ago.
http://groups.google.com/group/sci.s...054dc0607262a4
Basically, the airflow in the boundary layer, turbulent or laminar, has
passed through a bow shock, and then is expanded as it flows around the
wing. Compressed in the shock wave to 10000F, much of the energy is then
used to decompose the air into O and N and the temperature decreases to
3000F before coming into contact with the RCC. As the air flows around the
wing, it's actually going through an expansion. Decreasing the temperature
of the O2, N2, O, N, NO plasma. This is the environment the tiles find
themselves in, across the entire bottom of the Orbiter.

To me there must be a hysteresis effect to the chemical reaction. The
actual time in the bow shock and the extreme high temperatures cause the
decomposition of the air to occur rather quickly. But, as the air flows
around the wing and is expanded, the opposite reaction where the O and N
recombines into O2, N2 and NOx is much much slower. So, the temperature of
the air in the boundary layer, turbulent or not, is within the temperature
range that the tiles can handle.

Near the middle of the wing and at the wheel bay, all the air in the
boundary layer has passed through a bow shock, decomposed, then as
been expanded significantly. For the nose of the Orbiter and directly
behind it, the expansion was 60 degrees. At the nose, the air in the
boundary layer has gone from zero velocity, thru Mach 1, and continued
acceleration up to hypersonic velocity as it is expanded 60 degrees around
the curved surface of the RCC nose cap.

--
Craig Fink
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