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Ralph Nesbitt
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 Posted: Sat Aug 30, 2003 10:07 pm Post subject: Re: CAIB report: Change management. OK, by the way, get good |
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"Craig Fink" <webegood@earthlink.net> wrote in message
news:9SJ3b.280$tw6.118@newsread4.news.pas.earthlink.net...
[quote]ElleninLosAngeles wrote:
rgregoryclark@yahoo.com (Robert Clark) wrote
two very high level NASA shuttle program managers made the statement
that if the shuttle thermal protection system was damaged "nothing
could be done." This is VERY bad.
Another key fault was just taking unquestioningly the conclusions of
the Boeing engineers who suggested safe return. It should be
instinctively obvious to a manager that the contractor responsible for
a system would put a positive spin on a report detailing its possible
failure. For this reason a good manager would naturally have such a
report vetted by experienced independent engineers.
The report authors just assumed that if the
damage was simply LESS than the dangerous level indicated by their
computer program (the CRATER program for the tiles) or prior test data
(ice impact data for the RCC panels), that means it has to be safe.
This is EXTREMELY bad without further test data to support that
conclusion.
These are good points that I really agree with. I>m still wondering
why managers said nothing could be done if the TPS damage was extreme.
It sounds so cold - I>m wondering what they were thinking about at the
time they said it... maybe they said this as a way to end the
discussion about TPS damage and move on to other problems they were
working, thinking there was no way foam was going to create a hole in
the orbiter? Likewise, no one seemed too interested in knowing how the
engineers came to their conclusion that the damage would be minimal.
And, that the employees were allowed to make the "qualitative
extrapolation" from Crater predicting a burn thru to it being not a
burn thru because foam is light, hasn>t happened before, RCC panels
should be tough, etc. is the worst. It>s as if no one was looking over
their shoulders to see what they were doing, and they knew it!
Transcript Excerpts from the January 21,Mission Management Team Meeting
Linda Ham
...and density of the foam wouldn>t do any damage.So we ought to pull that
along with the 87 data where we had some damage,pull this data from 112 or
whatever flight it was and make sure that you know I hope that we had good
flight rationale then.
Jan 22 9:14 AM Email (Re: ET Foam Loss) from Linda Ham to Ron Dittemore
You probably can>t open the attachment.But,the ET rationale for flight for
the STS-112 loss of foam was lousy.Rationale states we haven>t changed
anything,we haven>t experienced any safety of flight damage in 112
flights,risk of loss of bi-pod ramp TPS is same as previous flghts...So ET
is safe to fly with no added risk Rationale was lousy then and still
is....
January 22,2003 9:33 AM Email (Re: ET Foam Loss) from Linda Ham to Lambert
Austin
Can we say that for any ET foam lost, no "safety of flight" damage can
occur to the Orbiter because of the density?
Jan 22,2003 10:15 AM Email (Re: ET Foam Loss) from Ron Dittemore to Linda
Ham
Another thought,we need to make sure that the density of the ET foam
cannot
damage the tile to where it is an impact to the orbiter...Lambert and
Ralph
need to get some folks working with ET.
Jan 22,2003 10:53 AM (Re: ET Foam Loss) Schomburg to Roe regarding Linda>s
question.
No-the amount of damage ET foam can cause to the TPS material-tiles is
based on the amount of impact energy-...
Jan 22, 2003 3:22 PM (Re: ET Foam Loss) Lamberts to Linda Ham regarding
her
question
NO.I will cover some of the pertinent rationale....there could be more if
I
spent more time thinking about it.Recall this issue has been discussed
from
time to time since the inception of the basic no debris requirement in
Vol..X and at each review the SSP has concluded that it is not possible to
PRECLUDE a potential catastrophic event as a result of debris impact
damage
to the flight elements. As regards the Orbiter,both windows and tiles are
areas of concern.
You can talk to Cal Schomberg and he will verify the many times we have
covered this in SSP reviews.While there is much tolerance to window and
tile damage,ET foam loss can result in im- pact damage that under
subsequent entry environments can lead to loss of structural integrity of
the Orbiter area impacted or a penetration in a critical function area
that
results in loss of that function. My recollection of the most critical
Orbiter bottom acreage areas are the wing spar,main landing gear door seal
and RCC panels...of course Cal can give you a much better rundown.
Essentially, Linda Ham is told that she can>t use that density (softness)
of the foam rational to say that the heatshield will not be damaged by the
foam. Also, Labert tells her that the RCC panels are one of the most
critical parts.
The density (softness) rational that Linda Ham suggested on Jan 21 at the
MMT is used in the Boeing report anyway.
Boeing report date Jan 23th, give on the 24th.
Page 8: RCC is clearly capable of withstanding impacts of at least 15
degrees;relative softness of SOFI (compared to ice)would indicate greater
capability
But the impact was greater than 20 degrees, Looking at Page 10, only one
RCC impact damage study run.
Page 10:
Test Case 2:
Location: RCC Panel 9 Lower Flange OML (Coating Missing)
Assumptions: Coating loss and Carbon substrate exposed
Results: Substrate thickness: 0.193 inches Loss 0.09 inches No issue
Note that test cases 5 and 6 were never run and no results presented.
There
was no way for Boeing to run test case 6 as it involved "several tiles
lost" and the only way to figure out how many tiles "several" is, is to
take a look at the damage.
Note that on page 10 RCC damage is reduced to 0.09 inches, due to the
density or softness rational. Looking at page 8, 0.09 inches damage
coorisponds to an impact of less than 5 degrees on the RCC. The table was
output from the Crater like program that is looking at impact energy,
which
is the relevant parameter, not some touchy feely softness rational to
reduce the angle of impact by over 80% to around 4 degrees.
Also, I could be wrong here, the study may have been 0.00 inches of debris
damage and only coating loss, with 0.09 inches being how much of the RCC
thickness will burn away on entry. So, the density/softness rational may
have been used to eliminate all damage (other than coating) RCC panal due
to the impact.
Angle (deg) Velocity(fps) Damage (in)
5 720 0.11
10 720 0.18
15 720 0.23
20 720 0.28
25 720 0.33
Moral of the story, don>t write the conclusions to a report before the
analysis is complete.
Dead Men Orbiting and Plausible Deniability, "and that>s the way it played
out."
Craig Fink
Anyone who has ever dealt with a problem of "unknown dimension" will tell[/quote]
you to expect/plan for the "Worst Case Scenario". It is better for reality
to prove "Worst Case Scenario" to be over reach than "Short Fall"
Ralph Nesbitt |
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kevin
Guest
|
| Posted: Sun Aug 31, 2003 4:18 am Post subject: Re: CAIB report: Change management. OK, by the way, get good |
|
|
In article <jbysxveflzcngvpbpna.hkcsoa1.pminews@news1.sympatico.ca>,
wwolfkir@sympatico.can says...
[quote]On 28 Aug 2003 10:25:38 -0700, Robert Clark wrote:
The U.S. military has recognized this and has conducted studies on
what qualities allow their officers to make good decisions in the
field. They were dismayed with the decision making of some of their
young officers in simulated battle exercises. In one of the studies
they brought in some Wall Street traders and compared their decisions
to those of young officers in battle simulations. The Wall Street
traders won consistently eventhough they didn>t have specific
experience with these battle simulations. This says to me there is
such a thing as good overall decision making ability.
No, it means that the traders have learned to make decisions under pressure.
[/quote]
Yah, but they demonstrably do *NOT* make good decisions. Witness the
fact that the best way to make money in the stock market is just buy and
hold a bunch of different stocks. In the extreme, the best stock pickers
(the guys who run the mutual funds) have not demonstrated the ability to
pick stocks that consistently outperform the major stock indexes. That>s
not the kind of the decision maker that should be leading battles.
--
Kevin Willoughby kevinwilloughby@acm.orgNoSpam
Imagine that, a FROG ON-OFF switch, hardly the work
for test pilots. -- Mike Collins |
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Craig Fink
Guest
|
| Posted: Sun Aug 31, 2003 9:13 pm Post subject: Re: CAIB report: Change management. OK, by the way, get good |
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|
Ralph Nesbitt wrote:
[quote]
"Craig Fink" <webegood@earthlink.net> wrote in message
news:9SJ3b.280$tw6.118@newsread4.news.pas.earthlink.net...
ElleninLosAngeles wrote:
rgregoryclark@yahoo.com (Robert Clark) wrote
two very high level NASA shuttle program managers made the statement
that if the shuttle thermal protection system was damaged "nothing
could be done." This is VERY bad.
Another key fault was just taking unquestioningly the conclusions of
the Boeing engineers who suggested safe return. It should be
instinctively obvious to a manager that the contractor responsible for
a system would put a positive spin on a report detailing its possible
failure. For this reason a good manager would naturally have such a
report vetted by experienced independent engineers.
The report authors just assumed that if the
damage was simply LESS than the dangerous level indicated by their
computer program (the CRATER program for the tiles) or prior test data
(ice impact data for the RCC panels), that means it has to be safe.
This is EXTREMELY bad without further test data to support that
conclusion.
These are good points that I really agree with. I>m still wondering
why managers said nothing could be done if the TPS damage was extreme.
It sounds so cold - I>m wondering what they were thinking about at the
time they said it... maybe they said this as a way to end the
discussion about TPS damage and move on to other problems they were
working, thinking there was no way foam was going to create a hole in
the orbiter? Likewise, no one seemed too interested in knowing how the
engineers came to their conclusion that the damage would be minimal.
And, that the employees were allowed to make the "qualitative
extrapolation" from Crater predicting a burn thru to it being not a
burn thru because foam is light, hasn>t happened before, RCC panels
should be tough, etc. is the worst. It>s as if no one was looking over
their shoulders to see what they were doing, and they knew it!
Transcript Excerpts from the January 21,Mission Management Team Meeting
Linda Ham
...and density of the foam wouldn>t do any damage.So we ought to pull
that along with the 87 data where we had some damage,pull this data from
112 or whatever flight it was and make sure that you know I hope that we
had good flight rationale then.
Jan 22 9:14 AM Email (Re: ET Foam Loss) from Linda Ham to Ron Dittemore
You probably can>t open the attachment.But,the ET rationale for flight
for the STS-112 loss of foam was lousy.Rationale states we haven>t
changed
anything,we haven>t experienced any safety of flight damage in 112
flights,risk of loss of bi-pod ramp TPS is same as previous flghts...So
ET is safe to fly with no added risk Rationale was lousy then and still
is....
January 22,2003 9:33 AM Email (Re: ET Foam Loss) from Linda Ham to
Lambert Austin
Can we say that for any ET foam lost, no "safety of flight" damage can
occur to the Orbiter because of the density?
Jan 22,2003 10:15 AM Email (Re: ET Foam Loss) from Ron Dittemore to
Linda Ham
Another thought,we need to make sure that the density of the ET foam
cannot
damage the tile to where it is an impact to the orbiter...Lambert and
Ralph
need to get some folks working with ET.
Jan 22,2003 10:53 AM (Re: ET Foam Loss) Schomburg to Roe regarding
Linda>s question.
No-the amount of damage ET foam can cause to the TPS material-tiles is
based on the amount of impact energy-...
Jan 22, 2003 3:22 PM (Re: ET Foam Loss) Lamberts to Linda Ham regarding
her
question
NO.I will cover some of the pertinent rationale....there could be more if
I
spent more time thinking about it.Recall this issue has been discussed
from
time to time since the inception of the basic no debris requirement in
Vol..X and at each review the SSP has concluded that it is not possible
to PRECLUDE a potential catastrophic event as a result of debris impact
damage
to the flight elements. As regards the Orbiter,both windows and tiles are
areas of concern.
You can talk to Cal Schomberg and he will verify the many times we have
covered this in SSP reviews.While there is much tolerance to window and
tile damage,ET foam loss can result in im- pact damage that under
subsequent entry environments can lead to loss of structural integrity of
the Orbiter area impacted or a penetration in a critical function area
that
results in loss of that function. My recollection of the most critical
Orbiter bottom acreage areas are the wing spar,main landing gear door
seal and RCC panels...of course Cal can give you a much better rundown.
Essentially, Linda Ham is told that she can>t use that density (softness)
of the foam rational to say that the heatshield will not be damaged by
the foam. Also, Labert tells her that the RCC panels are one of the most
critical parts.
The density (softness) rational that Linda Ham suggested on Jan 21 at the
MMT is used in the Boeing report anyway.
Boeing report date Jan 23th, give on the 24th.
Page 8: RCC is clearly capable of withstanding impacts of at least 15
degrees;relative softness of SOFI (compared to ice)would indicate greater
capability
But the impact was greater than 20 degrees, Looking at Page 10, only one
RCC impact damage study run.
Page 10:
Test Case 2:
Location: RCC Panel 9 Lower Flange OML (Coating Missing)
Assumptions: Coating loss and Carbon substrate exposed
Results: Substrate thickness: 0.193 inches Loss 0.09 inches No issue
Note that test cases 5 and 6 were never run and no results presented.
There
was no way for Boeing to run test case 6 as it involved "several tiles
lost" and the only way to figure out how many tiles "several" is, is to
take a look at the damage.
Note that on page 10 RCC damage is reduced to 0.09 inches, due to the
density or softness rational. Looking at page 8, 0.09 inches damage
coorisponds to an impact of less than 5 degrees on the RCC. The table was
output from the Crater like program that is looking at impact energy,
which
is the relevant parameter, not some touchy feely softness rational to
reduce the angle of impact by over 80% to around 4 degrees.
Also, I could be wrong here, the study may have been 0.00 inches of
debris damage and only coating loss, with 0.09 inches being how much of
the RCC thickness will burn away on entry. So, the density/softness
rational may have been used to eliminate all damage (other than coating)
RCC panal due to the impact.
Angle (deg) Velocity(fps) Damage (in)
5 720 0.11
10 720 0.18
15 720 0.23
20 720 0.28
25 720 0.33
Moral of the story, don>t write the conclusions to a report before the
analysis is complete.
Dead Men Orbiting and Plausible Deniability, "and that>s the way it
played out."
Craig Fink
Anyone who has ever dealt with a problem of "unknown dimension" will tell
you to expect/plan for the "Worst Case Scenario". It is better for reality
to prove "Worst Case Scenario" to be over reach than "Short Fall"
Ralph Nesbitt
[/quote]
I agree, some of what you say. A "Worst Case Scenario" should over reach as
opposed to "Fall Short". But when dealing with a real problem, with real
damage, in any parametric study of the consequence of possible future
damage, it is always best, if not imperative, to minimize the unknowns and
eliminate as many "unknown dimensions" as possible. This gives you the best
possible chance of having a positive outcome.
In this specific case, the RCC part of the Boeing study would better be
characterized as the "Best Case Scenario" in the face of overwhelming
evidence to the contrary. A study that was used to justify not taking a
look at the real damage and starting the parametric "Worst Case Scenario"
study from a position of knowledge, instead of ignorance.
Craig Fink |
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Derek Lyons
Guest
|
| Posted: Mon Sep 01, 2003 6:49 am Post subject: Re: CAIB report: Change management. OK, by the way, get good |
|
|
ellen@thiemedesign.com (ElleninLosAngeles) wrote:
[quote]These are good points that I really agree with. I>m still wondering
why managers said nothing could be done if the TPS damage was extreme.
It sounds so cold -
[/quote]
Reality is often cold. Emotion does not change facts.
D.
--
The STS-107 Columbia Loss FAQ can be found
at the following URLs:
Text-Only Version:
http://www.io.com/~o_m/columbia_loss_faq.html
Enhanced HTML Version:
http://www.io.com/~o_m/columbia_loss_faq_x.html
Corrections, comments, and additions should be
e-mailed to om@io.com, as well as posted to
sci.space.history and sci.space.shuttle for
discussion. |
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Robert Clark
Guest
|
| Posted: Wed Sep 03, 2003 5:44 am Post subject: Re: CAIB report: Change management. OK, by the way, get good |
|
|
The managers should not take all the blame though. There were just
given a bad report to work with.
How can you guard against bad analysis?
(President Bush would like to know the answer to that one in regards
to the CIA.)
Computer Program That Analyzed Shuttle Was Misused, Engineer Says
By JOHN SCHWARTZ
New York Times, August 25, 2003
"Mr. Richardson, who at 74 still runs marathons, said that if the
Boeing engineers had been sufficiently knowledgeable, they could have
performed calculations similar to the ones that he came up with after
the accident. Instead, he said, they relied on superficial training to
set in motion "one of the worst engineering calls of all time.""
http://www.nytimes.com/2003/08/25/national/nationalspecial/25CRAT.html?ex=1062648000&en=6d50bea47f5d0f52&ei=5070
Bob Clark
Craig Fink <webegood@earthlink.net> wrote in message news:<i8p4b.3733$Lk5.2@newsread3.news.pas.earthlink.net>...
[quote]Ralph Nesbitt wrote:
"Craig Fink" <webegood@earthlink.net> wrote in message
news:9SJ3b.280$tw6.118@newsread4.news.pas.earthlink.net...
ElleninLosAngeles wrote:
rgregoryclark@yahoo.com (Robert Clark) wrote
two very high level NASA shuttle program managers made the statement
that if the shuttle thermal protection system was damaged "nothing
could be done." This is VERY bad.
Another key fault was just taking unquestioningly the conclusions of
the Boeing engineers who suggested safe return. It should be
instinctively obvious to a manager that the contractor responsible for
a system would put a positive spin on a report detailing its possible
failure. For this reason a good manager would naturally have such a
report vetted by experienced independent engineers.
The report authors just assumed that if the
damage was simply LESS than the dangerous level indicated by their
computer program (the CRATER program for the tiles) or prior test data
(ice impact data for the RCC panels), that means it has to be safe.
This is EXTREMELY bad without further test data to support that
conclusion.
These are good points that I really agree with. I>m still wondering
why managers said nothing could be done if the TPS damage was extreme.
It sounds so cold - I>m wondering what they were thinking about at the
time they said it... maybe they said this as a way to end the
discussion about TPS damage and move on to other problems they were
working, thinking there was no way foam was going to create a hole in
the orbiter? Likewise, no one seemed too interested in knowing how the
engineers came to their conclusion that the damage would be minimal.
And, that the employees were allowed to make the "qualitative
extrapolation" from Crater predicting a burn thru to it being not a
burn thru because foam is light, hasn>t happened before, RCC panels
should be tough, etc. is the worst. It>s as if no one was looking over
their shoulders to see what they were doing, and they knew it!
Transcript Excerpts from the January 21,Mission Management Team Meeting
Linda Ham
...and density of the foam wouldn>t do any damage.So we ought to pull
that along with the 87 data where we had some damage,pull this data from
112 or whatever flight it was and make sure that you know I hope that we
had good flight rationale then.
Jan 22 9:14 AM Email (Re: ET Foam Loss) from Linda Ham to Ron Dittemore
You probably can>t open the attachment.But,the ET rationale for flight
for the STS-112 loss of foam was lousy.Rationale states we haven>t
changed
anything,we haven>t experienced any safety of flight damage in 112
flights,risk of loss of bi-pod ramp TPS is same as previous flghts...So
ET is safe to fly with no added risk Rationale was lousy then and still
is....
January 22,2003 9:33 AM Email (Re: ET Foam Loss) from Linda Ham to
Lambert Austin
Can we say that for any ET foam lost, no "safety of flight" damage can
occur to the Orbiter because of the density?
Jan 22,2003 10:15 AM Email (Re: ET Foam Loss) from Ron Dittemore to
Linda Ham
Another thought,we need to make sure that the density of the ET foam
cannot
damage the tile to where it is an impact to the orbiter...Lambert and
Ralph
need to get some folks working with ET.
Jan 22,2003 10:53 AM (Re: ET Foam Loss) Schomburg to Roe regarding
Linda>s question.
No-the amount of damage ET foam can cause to the TPS material-tiles is
based on the amount of impact energy-...
Jan 22, 2003 3:22 PM (Re: ET Foam Loss) Lamberts to Linda Ham regarding
her
question
NO.I will cover some of the pertinent rationale....there could be more if
I
spent more time thinking about it.Recall this issue has been discussed
from
time to time since the inception of the basic no debris requirement in
Vol..X and at each review the SSP has concluded that it is not possible
to PRECLUDE a potential catastrophic event as a result of debris impact
damage
to the flight elements. As regards the Orbiter,both windows and tiles are
areas of concern.
You can talk to Cal Schomberg and he will verify the many times we have
covered this in SSP reviews.While there is much tolerance to window and
tile damage,ET foam loss can result in im- pact damage that under
subsequent entry environments can lead to loss of structural integrity of
the Orbiter area impacted or a penetration in a critical function area
that
results in loss of that function. My recollection of the most critical
Orbiter bottom acreage areas are the wing spar,main landing gear door
seal and RCC panels...of course Cal can give you a much better rundown.
Essentially, Linda Ham is told that she can>t use that density (softness)
of the foam rational to say that the heatshield will not be damaged by
the foam. Also, Labert tells her that the RCC panels are one of the most
critical parts.
The density (softness) rational that Linda Ham suggested on Jan 21 at the
MMT is used in the Boeing report anyway.
Boeing report date Jan 23th, give on the 24th.
Page 8: RCC is clearly capable of withstanding impacts of at least 15
degrees;relative softness of SOFI (compared to ice)would indicate greater
capability
But the impact was greater than 20 degrees, Looking at Page 10, only one
RCC impact damage study run.
Page 10:
Test Case 2:
Location: RCC Panel 9 Lower Flange OML (Coating Missing)
Assumptions: Coating loss and Carbon substrate exposed
Results: Substrate thickness: 0.193 inches Loss 0.09 inches No issue
Note that test cases 5 and 6 were never run and no results presented.
There
was no way for Boeing to run test case 6 as it involved "several tiles
lost" and the only way to figure out how many tiles "several" is, is to
take a look at the damage.
Note that on page 10 RCC damage is reduced to 0.09 inches, due to the
density or softness rational. Looking at page 8, 0.09 inches damage
coorisponds to an impact of less than 5 degrees on the RCC. The table was
output from the Crater like program that is looking at impact energy,
which
is the relevant parameter, not some touchy feely softness rational to
reduce the angle of impact by over 80% to around 4 degrees.
Also, I could be wrong here, the study may have been 0.00 inches of
debris damage and only coating loss, with 0.09 inches being how much of
the RCC thickness will burn away on entry. So, the density/softness
rational may have been used to eliminate all damage (other than coating)
RCC panal due to the impact.
Angle (deg) Velocity(fps) Damage (in)
5 720 0.11
10 720 0.18
15 720 0.23
20 720 0.28
25 720 0.33
Moral of the story, don>t write the conclusions to a report before the
analysis is complete.
Dead Men Orbiting and Plausible Deniability, "and that>s the way it
played out."
Craig Fink
Anyone who has ever dealt with a problem of "unknown dimension" will tell
you to expect/plan for the "Worst Case Scenario". It is better for reality
to prove "Worst Case Scenario" to be over reach than "Short Fall"
Ralph Nesbitt
I agree, some of what you say. A "Worst Case Scenario" should over reach as
opposed to "Fall Short". But when dealing with a real problem, with real
damage, in any parametric study of the consequence of possible future
damage, it is always best, if not imperative, to minimize the unknowns and
eliminate as many "unknown dimensions" as possible. This gives you the best
possible chance of having a positive outcome.
In this specific case, the RCC part of the Boeing study would better be
characterized as the "Best Case Scenario" in the face of overwhelming
evidence to the contrary. A study that was used to justify not taking a
look at the real damage and starting the parametric "Worst Case Scenario"
study from a position of knowledge, instead of ignorance.
Craig Fink[/quote] |
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