NASA Astronaut on Columbia Repair (and others)

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 are confusing the issue. I do not take issue with the CAIB's
conclusion regarding the actual Columbia working scenario. My issue is
with the hypothetical repair scenario.

its about the hole grow by oxidation


The 2004 arcjet tests were higher fidelity than previous tests and
therefore invalidate the earlier test results you reference here. Prior
to the 2004 tests it was felt that the Nextel fabric would be adequate by
itself for the damage sizes quoted and that those sizes could be
established as the upper bound of the "No repair necessary" threshold.
After the 2004 tests, it was realized that this threshold needed to be
much lower.

The Nextel fabric is to cover the wing side of the RCC cavity to
prevent a burn thrugh of the steel plate there. This has no direct link
with the question of the oxidation rate of uncoated RCC crack surface.

You claimed to know data that the oxidation rate at the (uncoated)
crack surface of a RCC hole would prevent any repair effort. The
oxidation of the carbon would burn away most of the RCC during reentry.
And you claimed NASA had during CAIB no tests, but only theoretical
analyses to base one.

Now I presented evidence that NASA had prior tests on RCC hole grow.
And they had the experimental knowledge that the hole grow was not
relevant in the Columbia case. Tom even presented a report from 2000
on the issue:

http://ston.jsc.nasa.gov/collections...000-209760.pdf

Its about holes by hypervelocity impact with craters, worse then the hole
the foam did. The hole in Columbia`s wing probably looked like that
of the CAIB tests with the SWRI gun. Somwhat smaller and no crater.
That all shows NASA did a fair job in analysing the RCC oxidation
issue you brought up. I still see no evidence they screwed or covered
up something there prior to CAIB. And you were unable to present any
evidence that later experiments proved this data wrong.


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.

Incorrect. I knew about the RCC oxidation issue since I saw the
presentation charts for the arcjet test results in 2004. That was long
before I posted about it on Usenet.

Weeks or months? You posted it first at Sonday 15 Aug. 2004 13:28:
http://groups.google.com/group/sci.s...682495ca20e813
That it was "long before" just raised my doubts on your memory.


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.

"This guys" are not hiding anything. The shuttle is on the ITAR Munitions
List and all shuttle technical publications must be pre-cleared to ensure
that sensitive technologies are not compromised. The presentation in
question does not necessarily contain such information, but it has not
received the necessary Export Control pre-clearance and I am not about to
do that for the sake of a silly argument on Usenet.

That previous RCC oxidation data were wrong and a repair like CAIB
suggested therfore impossible - thats far beyond "the sake of a silly
argument on Usenet." If your claim be true NASA would have long ago
informed the Congress and the public about it. Like they did with
other Return To Flight issues. They even had an independent RFT TG
to supervice it. I saw in the RTF/TG documents no evidence for your
claims.

Maybe it was a presentation intended to
mind wash some people.

Highly doubtful. There were no references to Columbia at all in the
presentation and there is no indication that the presenters had any
motivation other than future RCC repair capability. The connection
between the results of the presentation and a hypothetical Columbia
repair scenario are entirely my own.

Here we are. You have no data in front of you to prove your claims
to yourself. You only might have the memory of something you heard
once. But probably your memory mangled your own conclusion with
what you heard. Thats more often the case then we want it to be.

Look, face it. There is absolutly no evidence for your claim. You
are the only source of this idea. No one else has brought it up.
Even NASA data prior CAIB supports this CAIB conclusion.

--
JRF



## CrossPoint v3.12d R ##

wrote:
The Nextel fabric is to cover the wing side of the RCC cavity to
prevent a burn thrugh of the steel plate there. This has no direct link
with the question of the oxidation rate of uncoated RCC crack surface.

You claimed to know data that the oxidation rate at the (uncoated)
crack surface of a RCC hole would prevent any repair effort. The
oxidation of the carbon would burn away most of the RCC during reentry.
And you claimed NASA had during CAIB no tests, but only theoretical
analyses to base one.

Now I presented evidence that NASA had prior tests on RCC hole grow.
And they had the experimental knowledge that the hole grow was not
relevant in the Columbia case. Tom even presented a report from 2000
on the issue:

http://ston.jsc.nasa.gov/collections...000-209760.pdf

Its about holes by hypervelocity impact with craters, worse then the hole
the foam did. The hole in Columbia`s wing probably looked like that
of the CAIB tests with the SWRI gun. Somwhat smaller and no crater.
That all shows NASA did a fair job in analysing the RCC oxidation
issue you brought up."



Original rcc hole size, and length of time the rcc material is exposed
to various heating situations during shuttle reentry determines the
boundary layer behavior as can be seen in the caib report vol v part 13
chapter 5 aerothermodynamic studies. The 2000 rcc oxidation study I
cited previously is to help achieve an understanding and assist in
correlation of caib data and previous studies discussing penetrated rcc
material and the processes that occur to the penetrated rcc during
shuttle reentry. As the reentering shuttle is dissipating the energy
from orbital velocity and traveling through the upper atmosphere in the
region of peak heating, managing heat is a chief concern (angle of
attack), and given that rough surfaces (gap fillers) or surfaces that
differ enough from the shape of the shuttles surface have a undesirable
dynamic effect on the energy transitions around the shuttle while
traveling at hypersonic velocities and can cause high heating such as
the case with "early" asymmetric boundary layer transitions then
any rcc repair method such as (ie a large patches from rough putty or
Nextel material), are valid concerns if the repaired rcc surface
doesn't maintain close to the same surface as the shuttles.

caib report vol 1 page 56 col 1 par 1
Wing Leading Edge Damage
The risk of micrometeoroid or debris damage to the RCC panels has been
evaluated several times. Hypervelocity im-pact 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 Inco-nel 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.
RCC components have been struck by objects throughout their operational
life, but none of these components has been completely penetrated. A
sampling of 21 post-flight reports noted 43 hypervelocity impacts, the
largest being 0.2 inch. The most significant low-velocity impact was to
Atlantis. panel 10-right during STS-45 in March and April 1992. The
damaged area was 1.9 inches by 1.6 inches on the exterior surface and
0.5 inches by 0.1 inches in the interior surface. The substrate was
exposed and oxidized, and the panel was scrapped. Analysis concluded
that the damage was caused by a strike by a man-made object, possibly
during ascent. Figures 3.3-2 and 3.3-3 show the damage to the outer and
inner surfaces, respectively.


STS-28 R Early Boundary Layer Transition
http://www.jsc.nasa.gov/news/columbi...lyboundary.pdf

NASA_17-5259
"OPERATIONAL EXPERIENCE WITH HYPERSONIC FLIGHT OF THE SPACE
SHUTTLE 17_5259
page 5 col 1 par 2
ASYMMETRIC BOUNDARY LAYER TRANSITION (ABLT)
Under normal conditions, boundary layer transition from laminar to
turbulent flow occurs approximately at the same time on both sides of
the vehicle (left/right), usually around Mach 8 for a space shuttle
entry. However, it occasionally occurs early (as early as Mach 19 on
STS- 73). Transition causes a sharp rise in the heating rate and the
thermal protection system (TPS) temperatures. This is magnified when
transition occurs early, which has resulted in slumped tiles and other
damage to the shuttle TPS. The higher heating has also aggravated the
effect of ascent debris impacts. This TPS damage has required
additional TPS refurbishment work during the turnaround for the next
flight.
Transition can also begin on one side of the vehicle, which temporarily
causes asymmetric drag, and rolling and yawing moments. The primary
consequence of this rolling and yawing moment disturbance is an
increase in RCS propellant usage at the onset of asymmetry, followed by
a second, smaller increase when transition occurs on the
other side of the vehicle, which eliminates the asymmetry. In vehicles
with limited aileron trim capability, this could also contribute to
aileron trim saturation in the presence of airframe and center of
gravity asymmetries. The time of transition is affected by the angle
of attack and the surface roughness. Transition can be triggered
slightly early by a roll reversal, which temporarily increases the
angle of attack in response to the decrease in drag caused by the
increasing altitude rate. However when transition occurs very early,
the cause is usually a protruding gap filler. There are gaps between
the TPS tiles to allow for thermal expansion. The gap fillers are
installed between the tiles to reduce hot gas flow to the filler bars
underneath these gaps. They occasionally become dislodged and
protrude in the flow, which can trigger early, and often asymmetric,
transition. This phenomenon caused some surprise when it was first
analyzed after STS-28."

"NASA/TP-2000-209760 Oxidation of Reinforced Carbon-Carbon
Subjected to Hypervelocity
Impact"http://ston.jsc.nasa.gov/collections/TRS/_techrep/TP-2000-209760.pdf

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

wrote in
:

The 2004 arcjet tests were higher fidelity than previous tests and
therefore invalidate the earlier test results you reference here.
Prior to the 2004 tests it was felt that the Nextel fabric would be
adequate by itself for the damage sizes quoted and that those sizes
could be established as the upper bound of the "No repair necessary"
threshold. After the 2004 tests, it was realized that this threshold
needed to be much lower.

The Nextel fabric is to cover the wing side of the RCC cavity to
prevent a burn thrugh of the steel plate there. This has no direct
link with the question of the oxidation rate of uncoated RCC crack
surface.

No, there is a link: the belief that the Nextel fabric would be
sufficient to protect the wing spar from superheated air entering from a
small hole or crack in the RCC was based on the assumption that the
hole/crack would not grow rapidly during entry. The 2004 arcjet test
results invalidated that assumption.

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.

Incorrect. I knew about the RCC oxidation issue since I saw the
presentation charts for the arcjet test results in 2004. That was
long before I posted about it on Usenet.

Weeks or months? You posted it first at Sonday 15 Aug. 2004 13:28:
http://groups.google.com/group/sci.s...682495ca20e813
That it was "long before" just raised my doubts on your memory.

About six months, then. The date of the presentation was February 11,
2004. Thank you for confirming the correctness of my memory.

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.

"This guys" are not hiding anything. The shuttle is on the ITAR
Munitions List and all shuttle technical publications must be
pre-cleared to ensure that sensitive technologies are not
compromised. The presentation in question does not necessarily
contain such information, but it has not received the necessary
Export Control pre-clearance and I am not about to do that for the
sake of a silly argument on Usenet.

That previous RCC oxidation data were wrong and a repair like CAIB
suggested therfore impossible - thats far beyond "the sake of a silly
argument on Usenet." If your claim be true NASA would have long ago
informed the Congress and the public about it.

Managers at the program level may not necessarily have known the details.
The Orbiter Return-to-Flight Working Group was a fairly low-level
meeting. Sometimes technical presentations at that level are later
presented directly to higher level meetings, but this particular
presentation was never brought before either the PRCB or the Daily PRCB.

It is more probable that the ORTFWG results were summarized and rolled-up
into a less detailed presentation to higher management. And the relevant
results of this one could be summarized in one statement: "RCC is more
fragile than we thought, therefore RCC repair is going to be more
difficult than we thought." And that statement, perhaps using different
words, *was* communicated to Congress and the public, repeatedly.

But that may not have been enough detail for managers to connect the dots
back to the Columbia repair scenario. Even if it had been, I don't
consider it a given that SSP management would have gone public about it.
It would have been seen as a remnant of the "defensive" management
mentality that the CAIB urged NASA to abandon.

Maybe it was a presentation intended to
mind wash some people.

Highly doubtful. There were no references to Columbia at all in the
presentation and there is no indication that the presenters had any
motivation other than future RCC repair capability. The connection
between the results of the presentation and a hypothetical Columbia
repair scenario are entirely my own.

Here we are. You have no data in front of you to prove your claims
to yourself. You only might have the memory of something you heard
once. But probably your memory mangled your own conclusion with
what you heard. Thats more often the case then we want it to be.

Look, face it. There is absolutly no evidence for your claim. You
are the only source of this idea. No one else has brought it up.
Even NASA data prior CAIB supports this CAIB conclusion.

Well, I can assure you that the presentation exists. It is not just
mangled memory; I have gone back and re-read it since this thread began,
and I stand by my previous statements. I can understand your skepticism
and reluctance to take my word for it, but that is all I have to offer.
If that is insufficient, then further discussion is pointless.

--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
think one step ahead of IBM.

On Mon, 20 Nov 2006 19:24:54 -0600, "Jorge R. Frank"
wrote:

Weeks or months? You posted it first at Sonday 15 Aug. 2004 13:28:
http://groups.google.com/group/sci.s...682495ca20e813
That it was "long before" just raised my doubts on your memory.

About six months, then. The date of the presentation was February 11,
2004. Thank you for confirming the correctness of my memory.

....As if any of us who mattered had any doubt, Jorge. When you're done
bashing the troll's head in, please make sure you wipe up the mess.
Then send his black soul to Killfile Hell where it belongs.

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

On Mon, 20 Nov 2006 19:24:54 -0600, "Jorge R. Frank"
wrote:

Well, I can assure you that the presentation exists. It is not just
mangled memory; I have gone back and re-read it since this thread began,
and I stand by my previous statements. I can understand your skepticism
and reluctance to take my word for it, but that is all I have to offer.
If that is insufficient, then further discussion is pointless.

....I think I speak for everyone here when I say that I'd take your
word as being more reliable than any notarized fact from this
particular troll.
OM
--
]=====================================[
] OMBlog - http://www.io.com/~o_m/omworld [
] Let's face it: Sometimes you *need* [
] an obnoxious opinion in your day! [
]=====================================[

On Mon, 20 Nov 2006 21:12:23 -0600, OM
wrote:

Well, I can assure you that the presentation exists. It is not just
mangled memory; I have gone back and re-read it since this thread began,
and I stand by my previous statements. I can understand your skepticism
and reluctance to take my word for it, but that is all I have to offer.
If that is insufficient, then further discussion is pointless.

...I think I speak for everyone here when I say that I'd take your
word as being more reliable than any notarized fact from this
particular troll.

Seconded.

Brian

Brian Thorn wrote:

Seconded.




The Handwaving Sergeant At Arms notes the motion has been seconded, and
calls for a vote. :-)

Pat

"columbiaaccidentinvestigation"
wrote:

long handwaving nonsense deleted.

I issued a challenge and a request for information - your
unwillingness or inability to reply or provide that information is
duly noted.

D.
--
Touch-twice life. Eat. Drink. Laugh.

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

Derek Lyons stated refering to his previous statement that i must show
roger boijoly's actions warrated a no go for launch of challenger on
the morning of jan 28 1986:"I issued a challenge and a request for
information - your unwillingness or inability to reply or provide that
information is duly noted"


Actually derek what is noted is that nasa management demonstrated the
same type of thinking on the morning of jan 28 1986, and that is a
launch must be proven to be not safe, so in your "noting process" of my
reply to you, you may want to reflect on how the rogers commission, and
diaz report what critique your thought of boisjolys actions. And yes
derek i went beyond you're request and showed the you the previous
flights to sts-51l, sts-61c's reports which clearly demonstrates srb o
ring seal burn through was occurring in cold weather launches, in
addition to the history documented by the rogers commission, and
changes in nasa recommended by both investigatory bodies into both
tragedies.

Now derek you still haven't answered my question, so with out you
snipping just answer what you would have done the morning of jan 28
1986?

No hand waving, no rhetoric, just answer, otherwise you cant even live
up to your own standards of criticism, just correlate your words to
reality, then you can state what you have said with authority,
otherwise you're opinion is not backed by anybody but you.

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

Derek Lyons wrote:"I issued a challenge and a request for information -
your unwillingness or inability to reply or provide that information is
duly noted."

Here derk I'll make it easy on you to explain "what you would have
done in roger boijsoly's place", given the following factual
history of the challenger tragedy specifically regarding srb O-ring
seal burn through problems in cold weather launch conditions, that led
to the tragic loss of the sts-51l crew, and challenger jan 28 1986.
So, Derek I would like you to correlate you're thinking in this
thread to the following historically correct documented facts from the
rogers commission where they state the following:
(*1).
"The teleconference between Marshall Space Flight Center, Kennedy
Space Center and Morton Thiokol, Incorporated, at Wasatch, Utah,
focused attention on the advisability of launching mission 51-L and
provided a clear opportunity for postponement",
and stated about nasa's flight readiness review meetings prior to
the tragic loss of sts-51l,
(*2).
"("STS 61-C (flight 24), launched on January 12, 1986, experienced
nozzle joint O-ring erosion and blow-by and field joint O-ring
erosion...." However, at the STS 51-L Level I Flight Readiness Review
On January 15, 1986, Mr. Mulloy noted that there were "No 61-C Flight
Anomalies," and that there were "No Major Problems or Issues.".

And before you start youre rant about (good vs evil) again, please
understand I have also provided the facts (and argued on a previous
thread) to show how nasa managers would directly benefit from a full
shuttle system quantitative risk assessment, in making their
professional decisions to operate and retire the space shuttle safely
within it's designed parameters and in compliance with all human
space flight procedures.

(*1)
http://history.nasa.gov/rogersrep/v2appg.htm
"Report of the PRESIDENTIAL COMMISSION on the Space Shuttle
Challenger Accident
Volume 2: Appendix G - Human Factor Analysis
Managers at Risk: The Human Factors of Launch Pressures
The teleconference between Marshall Space Flight Center, Kennedy Space
Center and Morton Thiokol, Incorporated, at Wasatch, Utah, focused
attention on the advisability of launching mission 51-L and provided a
clear opportunity for postponement. The decision should have been based
on engineering judgments. However, other factors may have impeded or
prevented effective communication and exchange of information. One
factor which may have contributed significantly to the atmosphere of
the teleconference at Marshall is the effect on managers of several
days of irregular working hours and insufficient sleep.
The extent of sleep loss was documented by Commission investigators who
conducted interviews with the teleconference participants at Marshall
and Kennedy specifically to reconstruct their daily activities during
the five days preceding the accident. As shown in Figure 2, these
interviews revealed that because of the launch scrub on January 27
certain key managers obtained only minimal sleep the night before the
teleconference or had arisen so early in the morning that they had been
awake and on duty for extended periods. 25
Time pressure, particularly that caused by launch scrubs and rapid
turnarounds, increases the potential for sleep loss and judgment
errors. This could be minimized by preventing launch support personnel,
particularly managers, from combining launch support duty with office
work on the same day. The willingness of NASA employees in general to
work excessive hours, while admirable, raises serious questions when it
jeopardizes job performance, particularly when critical management
decisions are at stake."


This link contains the shuttle flight readiness reviews with
information that pertained to the o-ring problem prior to the launch of
sts-51l

(*2)
http://history.nasa.gov/rogersrep/v2apph.htm
"Report of the PRESIDENTIAL COMMISSION on the Space Shuttle
Challenger Accident
Volume 2: Appendix H - Flight Readiness Review Treatment of O-ring
Problems
At the December 4, 1985 STS 61-C Shuttle Projects Board, Mr. Mulloy
noted "SRM joint O-ring performance within experience base." The
Commission's copy of the December 9, 1985 Marshall Center Board
briefing was incomplete; however, at the December 11, 1985 Level I
Flight Readiness Review, it was reported that there were "No 61-B
flight anomalies....
STS 61-C (flight 24), launched on January 12, 1986, experienced nozzle
joint O-ring erosion and blow-by and field joint O-ring erosion. The
right-hand nozzle joint primary O-ring was eroded 0.011 inches over an
8 inch span at the 162° location. There was blow-by past the primary
O-ring in the left-hand nozzle joint between the 255.6° and 334.8°
positions. The primary O-ring in the left SRM aft field joint was
eroded 0.004 inches over a 3.5 inch span at the 154° location...
The STS 51-L SRB Board Flight Readiness Review On January 3, 1986,
Shuttle Projects Board On January 8, 1986, and Marshall Center Board on
January 13, 1986, all occurred before the STS 61-C SRBs were available
for inspection. However, at the STS 51-L Level I Flight Readiness
Review On January 15, 1986, Mr. Mulloy noted that there were "No 61-C
Flight Anomalies," and that there were "No Major Problems or
Issues."...
STS 51-L (flight 25) was launched on January 28, 1986."

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