|
Columbia Accident Investigation Board Press Briefing
Tuesday, March 18, 2003
1:00 p.m.
Hilton Houston - Clear Lake
3000 NASA Road One
Houston, Texas
MS. BROWN: Thank you for coming. As
usual, we've got a phone bridge today. So at the end
of the briefing, we'll take some questions from the
audience here, followed by some questions from the
phone bridge. I'll turn it over to Chairman Hal
Gehman.
ADM. GEHMAN: Thank you very much. We'll
do the same thing we usually do. I have a few
introductory comments. We'll let each of the panel
members say what they and their fellow board members
are doing. Then we will throw it up to questions.
I literally have almost nothing here to
say, very few announcements to make. I'll be traveling
to Washington, D.C., tomorrow afternoon, tomorrow
evening; and on Thursday I'll appear before the Senate
Commerce, Science and Transportation Committee hearing
to give a progress report on how the investigation is
going.
Next week we'll hold public hearings down
at KSC on Tuesday and Wednesday and we'll be discussing
things that are relevant to what they do down at KSC,
which is shuttle refurbishment and launch and those
kinds of things, but most importantly, of course, is
the debris, the debris reconstruction.
The only other announcement that I have is that we have a number of interim recommendations
that are beginning to percolate up through the staff,
through the board. I'm not ready to announce any right
now, but we've always mentioned that when we came to a
conclusion on anything, that we would issue that when
we were confident. And we have a couple of them that
are bubbling up and they are at various stages of
maturity. When they're ready, you can expect that
we'll be issuing some interim findings and
recommendations.
So with that, we'll go right down the row
here and start off with Steve Wallace who, as you all
probably know by now, is in the group that we label as
operations and management things.
MR. WALLACE: Thank you, Admiral. My
colleagues to my right are going to show more hardware
and debris and chemistry sets today than I am. We're
really more focused on areas of decision-making and
communications, and that is very much the broad focus
of the efforts that our group is involved in right now.
As you know, Dr. Sally Ride joined the board and she's
part of our group and is, as we speak, heavily involved
in interviews on those subjects and is a wonderful
addition, brings a good perspective on all those
issues.
I want to talk a little bit about the
decision-making issue. We've heard an awful lot about
E-mails and particularly as regards requests for DOD
imaging assets, on again, off again. I think an
important thing to say about the E-mail trail is that's
certainly not the story. That's maybe a fraction of
it. So while we read and organize and storyboard and
try to figure out the whole story of what happened
specifically and what it says sort of culturally in
terms of communication practices and relationships
among different parts of the organization, we're
heavily involved in witness interviews. We're doing
typically several every day and will be for some time.
I would also like to say we are trying to be fair about
all this and not view this with perfect 20/20
hindsight. Obviously there are a lot of people who, in
retrospect, may have wished they had done something
differently, whether or not it might have affected the
ultimate outcome.
We are trying to sort out in all these
communications, E-mails, phone calls, whatever, what
really constitutes normal banter, normal what-ifing
versus something that's Ð keep that in context. We
certainly don't want to do anything that might have a
long-term effect of inhibiting healthy communication, healthy discussion among people with genuine technical
issues and general technical discussions. General
Hess, the other member of our group, and I, we'll be in
Washington this week. We'll be interviewing some very
senior NASA officials as well, which will give another
level of the same discussion.
Our group is also looking at the flight
readiness review, sort of certification of flight
readiness, all of those processes that lead up to a
launch. I'd like to say that everybody along the table
here has a piece of the foam. General Deal literally
has it today, but let me tell you what I will describe
as our piece of the foam. It's the deposition of prior
foam events in the flight readiness process. We have
the well-known foam event in STS 112, the subsequent
launching of STS 113 and STS 107. There were prior
foam events. I think the best way to characterize this
is we're going to do an audit of the whole history of
foam events and particularly their disposition in terms
of the subsequent flight readiness reviews.
Another area that our group is involved
in, although it's somewhat of a shared responsibility,
is return-to-flight issues. A lot of them are fairly
obvious and have been discussed in the media and openly
by NASA. I would say Ð and Admiral Gehman alluded to recommendations we will have Ð some of those will be
in the nature of sort of return-to-flight issues and
some of them will be longer term. I would say I don't
expect us to be in any contest with NASA Ð in other
words, they have some very good efforts underway at a
couple of different levels. I've been invited and
encouraged to follow along with them and sit in all the
meetings I want. I've done that. So this board is not
going to look to take any pride of invention or
authorship in terms of the whole return-to-flight
picture. I think we're all looking at the same goal.
Some of the things they are looking at Ð
first I'd like to comment on launch dates. NASA has
published some various launch dates, and I'm not sure
they have always made it clear that the last set of
launch dates they put out clearly were dates that were
notional, if everything were done right today, the
first time we could possibly launch would be such and
such a date and the second of which is, by the way,
we're going to readjust all those dates later on. I
think it's quite safe to say those are for planning
purposes. They don't expend a lot of overtime and
resources unnecessarily. Those are just long-term
planning dates.
Specific areas where they have actions underway. Obviously the bipod foam issue has been
going on actually for some time, from 112. They have
an extensive program that's well along. Other areas
that they are looking at and we are looking at, of
course, on-orbit and on-station repair capability.
It's a very complex issue. And a broad scheme Ð this
is both NASA has efforts under way and we'll be
probably adding some further suggestions on imaging
capability both on ground-based and space-based assets.
And they're also looking at entry profiles, although
again this is a troublesome issue. We keep asking all
the experts, as we have these hearings, is there
anything else you can do in the entry profile. I think
the short version is that in any certified procedure
there's just very little to be gained. I think they're
looking to see even where there might be some possible
incremental improvements.
So that's the update from our group.
ADM. GEHMAN: All right. General Deal.
GEN. DEAL: Thank you, sir. I'd like to
thank you all for the opportunity to talk to you again.
Our panel, again, is the one that's looking at material
and maintenance and also various aspects of management.
We're going from being simply wide to being pretty much
deep and wide in the things that we're doing right now and following the foundation of no assumptions because
our objective, as we all will state, is to examine
everything objectively.
Kind of what our weekly report is and
what we've been up to, we've been on the road in this
last week. As a matter of fact, right now I'm the only
group board member that's in town. General Barry, who
was with you this morning for the hearing, has just
taken off for D.C. Admiral Turcotte was at Kennedy
Space Center last week; and he is currently up in
Dallas, examining the reinforced carbon-carbon panel
processing and processes up there. As for myself, I
was in Colorado doing interviews last week. I was at
Kennedy Space Center with Admiral Turcotte, after which
I spent some time with the folks at Michoud in
New Orleans.
We're cutting a pretty wide swath as we
do what the Admiral calls our gumshoe work. I'm going
to show a few examples of the spectrum of what we're
doing shortly. We're auditing paper processes. You
can image in processing the shuttle how many reams and
reams and reams of paper there is, and we've got teams
that are looking at each aspect of that.
We're examining and then also having
various aspects demonstrate the non-destructive examination techniques that currently exist and that
are used. We have some initial looks now going into
the quality verification processes, which are still
fundamental to shuttle operations. Toward that end,
we've been conducting multiple interviews, over
30 interviews in the last week with technicians, with
contract quality inspectors, with government
inspectors, and also with management, looking at each
person, several different processes of how they put
their stamps on different processes.
In case you're not familiar, each
technician and inspector carries a little miniature
stamp around with them and when they have finished,
rather than signing their whole name and all this other
kind of stuff, they have a stamp with a number. We are
looking at those processes. We've already talked to
some of those inspectors, referenced their numbers, and
by the paperwork that we're examining and auditing
we're able to go back and see who we want to conduct
future interviews with because that is a technician
that has stamped this particular procedure on Columbia
or on other shuttle processing.
You're going to continue to see more and
more matrixing amongst the groups. Some of the things
we're doing with Mr. Wallace or with Dr. Hallock. With Group 3's lead right now, we're monitoring some
testing. Yesterday and today we're doing testing down
at Michoud on the bipod ramp on one of the tanks. Last
week and this week we're at Wright Patterson Air Force
Base doing some things I'll show you on slides shortly.
So quality programs will remain a key
area of examination for us. NASA inspections, as some
of you have printed in your articles, are well down
across the board. Most of those inspections have been
shifted to a contractor, not unlike what the rest of
industries have been doing. So the government
mandatory inspection points, what was commonly referred
to as GMIPs, are NASA's quality verification, kind of
their last line of defense. Part of what we're doing
is doing interviews and also examining the processes
themselves to verify that those are on track and that
we also have the right people with the right
qualifications doing those things.
I'll give you an example of some of the
quality verification that we have. The external tank,
which you maybe know is 15 stories tall, has thousands
upon thousands of inspection points and multiple
methods of inspecting them. You can multiply that to
the orbiter, which has many more parts, and the
complexity of it.
Admiral Gehman has directed from Day 1
that we remain balanced. So we're not looking just for
things that are off track or things that have gone
wrong. We're also looking for some things going right.
I'm going to show you some examples of that, and best
business practices, if those exist, for us to look at,
as well.
Then also, in addition to finding the
cause, another key aspect of what we're doing is to
eliminate what we believe is not a cause. I've
mentioned this before. We have been looking with
Mr. Wallace's group at the Spacehab and its payload.
We've been looking at boosters. We are not ready to
rule anything out yet, but we're getting pretty close
to ruling some of those things out.
Now I want to start by ruling out a
couple of things that some of you have printed about.
Down at Michoud last week we had a test done, in part,
because early on there was some talk about the GX6300,
the adhesive for the ablative foam that was put on.
Now, someone had accused the folks down at Michoud of
having some old stock that they were using on the
shuttle. Well, we found out that if you mix it
properly and everything is done well, it's done like in
a pharmacy. You walk into this area and if you're a technician, you're the patient bringing in a
prescription and your prescription is your request for
the adhesive. It's processed through one technician;
another technician takes it and starts to mix up the
components. They mix it up in the proper amounts,
usually in a quantity of a pound. So we're not talking
50 pounds or a drumful of things; we're talking about a
small area 'cause it's got such a short shelf life to
it, 90 minutes. Then they take a sample of that and
they go and put it in an oven and quick bake it so they
can make sure it's got the right properties. Then they
issue it to the technician who goes and does it.
Now, if a sample of this did happen to be
sitting on a shelf and did get past that and someone
tried to use it, you can see that they couldn't use it.
It hardens up pretty well. Those of you on the
telephone bridge won't be able to experience this, but
any reporter that wants to come up afterwards and touch
it, you're more than welcome to. So that kind of
eliminated that, as long as the foam is mixed properly
or the adhesive is mixed properly.
We went a step further. There's a
Conothane that's the sealant in the primer that goes on
the tank and has to cure for eight hours before foam is
put on and also put inside of a patch if you have a damaged foam. We had them mix some of that up, and
it's got a shelf life of 60 minutes. Then we went back
a few hours later; and again, it's the same type of
story. This is kind of like rubber versus being hard.
We also looked into how they test the
foam whenever they're applying it to the tank. Every
time they fly it, they go through viscosity checks.
Then they also have about a 3-foot-by-3-foot aluminum
test sample, which this is a portion of one, that they
spray some of that foam on. Then they take that and
they do various tests on that test sample that they had
just sprayed on the tank, things such as pull tests to
make sure it will withstand any type of pulling on the
outside.
Then we had them, while we were down
there, show us a foam repair. There's going to be an
example here that you can come up and touch later on.
We had them do a cross-section first. We put the
Conothane in and we put the foam in there and do a
cross-sectional cut for us. So we're looking at all
those type of processes, as well.
I'd like to jump now into a few briefing
slides for you. Again, I'm going to talk about the
spectrum of things that we're looking at with the
Admiral, looking at everything from bad to good to just, by the way, we need to evaluate these type of
things. One of them Ð just a little bit of background
information for some who may not be aware about the
evolution of the bipod ramp design, which has been a
big focus that Mr. Wallace discussed.
Next slide. For ETs 1 through 13, you
had a pretty dramatic ramp. There was 45 degrees that
came off. Back here you have the first few shuttle
flights, a developmental flight instrumentation box
that was also enclosed in foam. That went away after
the first few flights. So pretty dramatic at the
beginning and then they changed it.
Next slide. For Tanks 14 through 75,
they greatly smoothed out that curve down to
30 degrees. So you can see the evolution starting.
Next. This is Tanks ET 76 through the
present. It's going down inside of the foam that's on
the tank. That's a picture of it actually on the
external tank with a fully foamed area. Then this, for
your information, was off of Flight 112. Mr. Wallace
referred to the back corner that came off of the bipod
ramp that went down and struck a component of the
booster. So we're looking at how it has evolved and
also looking at what NASA has been doing about it Ð
two flights ago, as Mr. Wallace mentioned, we lost a piece of it Ð and how we've come and what we're doing.
As some of you are already aware, NASA's already moving
to remove the ablative material that goes under the
bipod ramp which has been consistent on all the tanks.
Next. We're going to be looking at,
okay, how do we evolve from that to that to that and
what is the next design that they are already working
on, as well.
Next. Radar signature testing. I
mentioned it's happening right now at the Air Force
research lab at Wright Patterson Air Force Base. We're
doing testing for two purposes. One is for that
mysterious object that we talked about that was seen
from Day 2 to Day 4 on orbit of the orbiter, to try to
see what type of radar characteristics we may be able
to get out of this testing if we could perhaps
determine what it was that separated from the shuttle
and then reentered a few days later.
The other thing we are testing is various
components of the shuttle to help the debris team try
to predict what things were falling off and being shed
from the shuttle from the California coast on inward.
From the videos that we have, we're trying to see what
type of characteristics they are, because we have radar
signatures of a lot of this as it was falling to the ground. By testing at these various frequency ranges,
we're hoping to be able to identify what some of the
parts were.
Next. We've got 28 different materials
being tested right now at the research lab, everywhere
from different types of blankets to RCCs to various
tiles to the Freestar which, as you know, is kind of a
piggybacked payload that sits in the back of the
payload bay, to different types of foam and external
tank components and some seals, as well. Reports
should come by the next time we do a press conference
with you so that we can give you a little more details
on that. Probably be released even earlier than that.
I also want to go back to reemphasize a
couple of things about this mysterious object. To
remind you, this was discovered after the accident
versus while it was on orbit. This was not something
being tracked while it was on orbit. This was a result
of about six days later of what we like to call the
most laborious examination in space command history.
If you think about the orbiter as it's going around the
globe, there are 3180 different observations of the
shuttle. Now, this was more keeping track of the
shuttle versus tracking the shuttle, 'cause that's not
the mission; we're not tasked to do that in space command. We do track for it and we do de-conflict it
with any known objects in space, but they weren't doing
this fine-tooth examination while it was on orbit. So
I just want to make that point that this was after the
accident.
Next. This is just an example of some of
the things we're looking at. Again, it's not that we
think it has anything to do with the Spacehab, but we
have to eliminate it. If you look at Spacehab, it's
got the blankets that are all over it for protection.
Every place where you see one of those little dark
spots, that's just this little seal here that's
connected to a ring button on the other side, kind of a
protruding ball which snaps into the area. These are
all pull-tested before the Spacehab orbiter flight.
Could one come off? Possibly. Did it? Probably not.
That's one of the things they're testing at Wright
Patterson.
Next. As I said, the Admiral's got us
trying to keep as balanced an approach as we possibly
can in everything that we do. I want to give you an
initial look. This is by no means a final look but
some things that we think on the surface so far are
going right.
Next slide. Particularly I want to show you something different. Again, this isn't necessarily
related to where heat protruded inside the wing; but
it's an overall thing that bears looking at. If you go
down at Kennedy Space Center, for those of you who've
been there, you can't turn around without seeing
various posters that are there. USA's got these little
things: "Safety Is An Attitude." They've got
something that personalizes it a little bit. There's
Astronaut Eileen Collins and her daughter and Don
Thomas and his son, these posters that are around there
to personalize it.
Again, you can't turn around without more
visible reminders. Things that are being reflected
through our interviews, as well. Again, these are the
surface; and we're still prying beneath them. These
are initial impressions.
Next. There are some active methods. If
someone wants to speak out and say something is wrong
if you've got a process going on, an in-process leader
can halt an action at any single time it's going on.
Lockheed Martin has a card down at Michoud. I've got
one now that I'm carrying. It's that left card up
there. It's how to conduct a huddle if you think
something's going wrong. If you look at the very
bottom of it, it says: "This is stupid." You throw the card down and you can stop the process. I call
that the "This is stupid" card.
Then you go to USA and they've got a
great card. People carry multiple cards like this
time-out card. If anybody sees anything going wrong,
they can throw it down. As a matter of fact, Admiral
Turcotte saw that used by a junior technician as he was
observing the Atlantis being de-mated last week down at
the Cape. USA also has what they call the RATS
program, which goes off to a huge matrix they have of
risk assessments and score cards that drill down very
deeply into their processes.
Next. When someone does speak out, there
used to be a program that some of our interviews have
given us down at the Cape called "Week at the Beach."
You bring something out, and you got to spend a week at
the beach for stopping the processing. It wasn't like
you and I would want to spend a week at the beach; it
was week unpaid at the beach for slowing down the
processing. That mind set has disappeared, according
to interviews we've had so far.
Examples of some of the things USA has
touted. Some of their technicians had them eat lunch
with a NASA administrator. This is a particular one
from Michoud, won a $2500 award, was touted in both the Lockheed publication as well as NASA publications.
NASA astronauts give something called a Silver Snoopy
award. They give it out to technicians and NASA
employees. There's a lot of awards that are available
for cash and also recurring awards programs.
Next. Then you'd like to think that all
of those would bring out the inputs that you want. If
not, you can't hardly turn around without seeing these
things that are projected up there. There's anonymous
input forms that go directly to the NASA headquarters
safety reporting system. So anyone in any level can
send these things in anonymously, as well.
Next. So I've kind of given you a little
bit of the spectrum of some of the things we're looking
at, all the way from design through the testing through
some of the different practices. I'd like to leave you
with two quick points. One is that as a group and a
board, as Mr. Wallace alluded to, we're examining how
NASA defines what an acceptable risk is. For example,
the foam losses in past missions, you've got to look at
how and when and why and to what extent foam loss
became acceptable.
The other thing we're looking at is you
have to look at how the bulk of NASA is contracted out.
You've got to examine, when do you that, not just the contractor performance but also the contract that
they're performing to. You could have a lousy
contractor and a great contract, or you could have a
fabulous contractor but the contract that they're
working to or the design that they're performing to is
inadequate. By definition, you may not get the product
that you need. So we're examining all those aspects;
and we've brought in some contract experts to help us,
as well.
Thank you for the opportunity to convey
where we're headed. Much is happening. There's much
to do. We'll look at, later, some of the things that
we're doing. Thank you.
DR. HALLOCK: Good afternoon. It's my
pleasure today to tell you what we've been doing on the
engineering and technical analysis group. First of
all, we have welcomed a new member on Friday. That is
Professor Doug Osheroff, who's head of the physics
department at Stanford University. He's joined us; and
I'm looking forward to many, many interesting
discussions.
In order to describe what the rest of us
have been doing over the last week or so, let me do it
in terms of starting at the ascent stage of a mission
all the way to the ending which, in this case, is the debris stage. First of all, Scott Hubbard, as I think
was mentioned, last week was at Southwest Research
because we are getting ready to do the tests on foam
again. Here we go, following the foam. We're all
interested in foam. They'll be doing some tests
starting in about two weeks, I believe, where they'll
be taking larger projectiles, the stuff that was done a
number of years ago in '99, I believe it was.
Basically 1 inch by 1 inch by 1 inch and 1 inch by
inch by 3 inches. Now we're trying to get much
closer to the sizes that we're seeing in that film that
I'm sure all of you have seen.
The second part has to do now with the
external tank. During this past week they've been
looking at External Tank No. 120, which I believe
they're calling a cousin tank. It's a bit different
except for the area that we're talking about, which is
the bipod area, where what they did is to do some new
nondestructive techniques in order to look at what's
happening in this area, in the foam in this area,
particularly the bipod area. So they did things like
X-rays and laser shearography. Then what they're
doing Ð in fact, they may be even doing it right
now Ð is they're actually going to cut into this foam
and actually cut it off and take a look at it, look behind it. Are there voids? Are there cracks? Are
there other things happening in this area? Remember, I
said that we're using this now in External Tank
No. 120, which is a cousin. All of this is really to
be a practice before actually going to the so-called
sister tank which would be ET 94. So after they do the
test that they're doing, as I say, in approximately an
hour, tomorrow maybe, then the idea is to sit down and
look at what happened and make sure that nothing was
introduced by doing those tests that would hurt it.
Then the decision will be made whether we will go and
look at, as I say, the sister tank, the one that was
used for the launch of Columbia. So that's with Scott.
I'm next in the group here, in that we're
looking at a lot of things. Now, we've been hearing a
lot obviously about foam and other things, but we're
also looking at a lot of things which really haven't
hit the headlines very much, because we still need to
look at those kinds of things. So what I've been
looking at are things like meteors. Could there have
been a meteoroid hit or a space debris hit on what's
going on.
The way we've been looking at that is the
spacecraft itself has a number of very sensitive
accelerometers on board. So what we're doing is, when they're not firing any of the reaction control jets,
looking at the data to see if maybe sometime there was
an event of some sort that occurred. We've looked at
approximately half the data so far and sort of starting
at the beginning of the mission and so far have not
seen anything, but we really do need to look at it to
see if it's true.
Another area Ð and this, by the way,
shows that we are listening to people in that a lot of
us have been getting E-mails and we've received a lot
of things at the board now that we've advertised an
E-mail address as well as a mailing address. People
have pointed out there was a large coronal mass
ejection. In my day we used to call those solar
flares. Let me call it a solar flare. This occurred
the day before the landing event, but the actual flare
component didn't come to the earth until after the
accident. However, there was a preceding shock wave
which really contains the high-energy particles. So
the question is: Could this have caused a problem?
Because it turns out that shock wave came into the
earth's environment just when the shuttle was beginning
its deorbit burn. To do that, we got in contact with
the NOA people in the space environment center. These
people are in Boulder, Colorado, as well as people at Hanscom Air Force Base. Now, these are people who
actually look at this data all the time because, as you
probably know, if you do have one of these events,
things could happen like all your cell phones will go
dead, which maybe is a good thing. That is one of the
consequences, and it has actually caused problems with
power grids, too. So they actually look at this to
tell people who have satellites to reorient the
satellite or reorient the space shuttle or reorient
something on the space station.
Basically what has come out of this
thing, it was basically of no interest. It was very
insignificant, but we still needed to look at it. Part
of the reason it was insignificant is this coronal mass
ejection occurred near the rim of the sun and so the
earth really only received a glancing blow. As I said,
there are a number of these things which we still need
to be looking at and hopefully putting a check mark
next to it, saying that I think we can dismiss that as
being a participant within this event.
The next thing to look at Ð can I have
that first slide? We've been talking a little bit and
heard more and more about this thing called the
photograph that was taken at Kirtland. In the upper
left, this is probably the view that you have seen before; but as you can see, the people out in
Santa Cruz have been work on it and using some very
elegant techniques to try to clean up that image.
That's what we're now seeing as this being the image.
It's cleaned up quite a bit, and we probably can't do
too much more about it. If you want to know the
details of how to do it, let's do it afterward. It's
very complex, but it's a very elegant technique.
So now the question is let's start
looking in here. Now, is that something where maybe
some RCCs are missing, leading edge type material? Is
that what that's showing us? We also see what looks
like maybe a protuberance. That's why, in talking to
those of you who were here this morning, I was asking a
question about seeing shock-shock interactions. That's
probably what that may be, is a shock-shock
interaction. Why is it there? Is it there because
something is missing? That's a question mark. That's
what we're looking at.
Very briefly, if you look down below
here, that's looking at that now. You remember earlier
that was interpreted as being maybe the tail or
something like that of the orbiter. Now that they've
cleaned it up, it looks like a plume here. Looking at
it closer, it shows something that may be actually a piece of debris. We're not clear, not absolutely sure
of that at this moment, but that's what that could be.
Moving on. Dr. Widnall has been spending
time, once again, really dealing with the aerodynamic
reactions and how aerodynamics and extreme heating
interact. In connection with that, she's also been
trying to look at what is the behavior of these things,
dealing both on the exterior part of the shuttle itself
but also what's going inside the wing, how do these
things affect everything.
Now, my next thing to talk about is what
Roger Tetrault's doing. Can I have the next viewgraph,
please?
You heard a little bit of this. We have
talked in the past about this particular piece. What
we're talking about here, that is on the side of the
door. This is supposed to represent the door. Here's
a picture of the door. Here's where that piece is
located. Basically the fuselage is over on this side.
The door on the left wing Ð assume this is a door for
a moment Ð opens this way. When it's open, it's close
to the edge of the orbiter itself. So it opens this
way.
Now, the interesting thing about that
when we talked about it before was that we are seeing a spray pattern here, showing, once again, that there's
hot gas. The superheated gas is escaping from inside
the wheel well, going outward. Well, now we have
another piece that's on the other side. And here it's
shown and it's right up against the spar that the RCC
and stuff gets attached to and it goes right up to the
edge here. And what are we seeing here but the same
thing. We're seeing the spray going now in the
opposite direction. And this is the side that has the
hinges on it. So what it actually had to be able to do
is not only go out one side but it's now spraying out
the other side where it has to fight against the hinges
and get up to where the seals are within the door
itself.
That's implying that we're talking about
something that's got some pressure behind it and a lot
of heat building up. How much heat? Well, you've seen
this picture maybe. I can't see it very well from here
but it's the uplock and the interesting thing about
that Ð can I have the next viewgraph, please Ð still
a little bit better Ð but the interesting thing about
this is, look right down here. There's a corner
missing. It has been melted off. This is titanium.
In fact, to be specific, it's called 6-4 titanium Ð
percent aluminum, 4 percent vanadium, and 90 percent of it is titanium. It melts at approximately
,000 degrees Fahrenheit. So now we have another thing
that's inside this door, inside the wheel well area
where the temperature, as we now know, thanks to this,
is up around 3,000 degrees. So that's a large
temperature.
We also can't say when all of this was
happening, but at least having the superheated air
coming out, this plume coming out on both sides of the
door, so that obviously means the door is still on.
When it eventually departed from the shuttle itself, we
can't tell at this point; but sometime during the event
we had very, very hot temperatures in here.
Now we want to look at what this material
that's been plated on it. It's very directional. So
we can tell from what direction all of this is
happening. Depending on what that is, it could be very
interesting. Again, it's aluminum. Well, we've seen
aluminum being sprayed everywhere. That could also be
chromium, for example, because there's chromium on the
landing gear strut. I don't know what it is yet. Once
we know what it is, we're going to start looking at it.
The question is: Do we really know this
is from the left wheel well? Well, we have found the
right door, the right landing gear door, and it has all four uplocks attached to it. So there's no question
that this is from the left wheel well. Which one of
the four uplocks is a question at this point which we
would like to be able to narrow down.
But now see what we have. We have an
interesting picture. We have a thing that we know was
3,000 degrees here. We have sprays of aluminum going
around in different places and so on. So what we're
hoping to be able to do is hone in on possibly where
this breach actually occurred. That's very important.
If we know where the breach originally occurred, now we
can work backwards to start saying is that a panel, is
it a carrier panel, or what is it, as being the place
where everything came in.
So that's the story of our people. We've
been pretty busy this past week, as you can see, but
things are becoming quite exciting in the sense of
having a lot of information telling us a lot of hints
as to what's there. We're not yet ready to turn around
and say here is the story, but we're getting many, many
pieces of that puzzle. Thank you.
ADM. GEHMAN: Thank you very much.
MS. BROWN: Okay. We can take some
questions. Go ahead.
ADM. GEHMAN: Orlando Sun, for General Deal. Could you elaborate on some of things you're
looking at to make the determination of whether or not
safety processes might have been eroded or changed as
they were transferred gradually from government to
industry; and have you seen any indications yet that
that might be the case?
GEN. DEAL: Well, I've given you the
initial impressions that we have; but I also want to
stress those are initial impressions. The way that you
get past the things that you see on walls is through
the interview process which we've started. Down at
Kennedy along the last week we did about 20 different
interviews and so far they're substantiating what you
see on walls, but we still have many, many more to do.
That's where you're asking the people that have been
working the shuttle systems for perhaps 20 years what
changes have you seen, are they positive changes, what
could be made better. A typical question we like to
ask every single interviewee is a "King for the Day" or
"Queen for the Day" kind of question: "If you were in
charge, what would you do to make the processing
better, the safety programs better, the quality
programs better?" We're getting some good inputs from
that and also getting some good reinforcement of the
current programs compared to those things, like I mentioned earlier, the "Week on the Beach" program,
which was not a positive program. So things are
looking good now. However, we're at just the Phase 1
of that. We have many more interviews to do to see if
that's consistent across the board from what everyone
is saying.
A SPEAKER: USA Today, for Dr. Hallock.
What kinds of things could give pressure to a jet of
hot gas or hot metal coming out of the wheel well?
DR. HALLOCK: Pressure is a relative
quantity. Here we're talking about, in order to be
able to get this thing to actually be pushing against
the door and making its way out, breaking through the
seals and so on. It has to have some impetus behind it
for that to happen. So the pressure that we're talking
about here is not like the pressure in your tires or
something like this. It's actually having enough
quantity of this material inside the wheel well.
Remember, we think it came in one way and there is a
vent in front of it, but there's no other exit place in
the wheel well itself. So the pressure is more because
more and more of this material is collecting in that
region and then obviously looking for a place to
escape.
A SPEAKER: Is that material plasma or hot gas from the outside?
DR. HALLOCK: It's the hot gases. Maybe
I should say a lot of people, particularly myself as a
physicist, when people say plasma, we shudder a little
bit. Plasma has a definition, and plasma means you
have about 20 to 30 percent of dissociated atoms in the
material. Here where we are talking about superheated
air, we don't have that particular situation. So I try
to talk all my compatriots into using that term rather
than using the term "plasma."
A SPEAKER: Associated Press, for either
General Deal or Dr. Hallock. The question was asked
earlier and there wasn't really an answer from the
panelists. The possibility of multiple breaches.
Could someone address that? Is that being seriously
considered by the board that perhaps there were
multiple breaches letting in the hot gases from
different places? And is there any more information on
the launch debris, what exactly it may have consisted
of and whether, indeed, there were just three pieces?
DR. HALLOCK: In terms of the multiple
breaches, we haven't dismissed that. The issue is,
once you get a breach of some sort and then all the
other things that are happening there, it's possible
that it would actually open up other breaches. Whether that's what's happened here, I don't know. Right now
in order to try to work backwards, do the problem
backwards, we're more or less assuming that it probably
came from one place. When we find that that won't
work, then we go to Plan B which says now let's say
let's suppose in this area it could have come from this
location and maybe in this area it could be another.
Once damage started going, particularly late in the
event here, a lot of areas are going to start opening
up. So it's very likely at the very end, before
everything broke up, that the whole wing could have
been exposed. So it's one big breach at that
particular time.
What was the other part?
A SPEAKER: Any more progress on what the
launch debris was and how many pieces may, indeed, have
come off?
DR. HALLOCK: I'm not aware of that.
A SPEAKER: General Deal, do you have
anything?
GEN. DEAL: I think his group is working
very closely with the NASA folks that are doing the
photo analysis and video analysis.
ADM. GEHMAN: There's been no change to
what we showed last time. We don't know any more, whether it was ice in the foam or whether it was one
piece or two pieces or three pieces. There's been no
change in that.
A SPEAKER: Washington Post. A question
for Admiral Gehman. You had mentioned today, sir, that
you were going to ask NASA to allow the board to have a
say in what kind of tests are conducted, especially in
terms of the wind tunnel tests and so forth, so that
you're not just analyzing results after they've been
conducted but actually saying what tests are being
conducted. Can you talk about what's prompting this
and how these requests are being received by NASA?
ADM. GEHMAN: I sure can. NASA has a lot
of people working on this problem and they have their
own investigation path which includes a couple of
techniques like bounding problems, for example. They
want to test something way at the right-hand edge of
the problem and something way out on the left-hand side
edge of the problem. We may have a different
investigation approach and may be interested in a
different piece of data or a different analysis or test
in order to pursue our approach. So as we become
aware Ð and we know just about everything that's
NASA's doing Ð as we become aware, for example, that
foam impact testing is just about to begin down at Southwest Research, we inject ourselves to make sure
that, as long as they're writing a contract to do some
testing, that they include our requirements at the same
time. This is now going on across the board, and we
are working this together. I couldn't be happier with
the response. And it's a team effort and it's working
great.
A SPEAKER: Dallas Morning News. You've
said that there are no givens and that you hope not to
beg any questions, but it almost seems as though return
to flight is a given. Are you all examining the
fundamental question of whether there should be a
return to flight, and is there unanimity or consensus
on that question?
MR. WALLACE: I would speak to return to
flight at two different levels. I would say that I
think in the days after the accident, the President
stated the country's position on manned space flight,
which is that it will continue.
As far as the board, we are looking at
return to flight in two ways. One is the short-term,
which I think we can define that as the return to
flight necessary to ensure the continued viability of
the International Space Station. That would be
probably the shortest-term return-to-flight issue.
Beyond that, the board may and I think
will reframe the debate, which has been held many times
and will probably be held again, on who should go into
space and why, what payloads require that people
accompany them. I was thinking now as we feel like
we're on the brink of war and how people are all
worried about friends and relatives who are going off
into a war zone, as I had the explanation of risks
involved in various activities described to me by some
experts, manned space flight is an order of magnitude
or two more dangerous than operating aircraft in a
hostile war zone. So I think that debate will go on
again as to who needs to go into space and why, but I
don't think we are going to answer that question.
A SPEAKER: CBS News. Two quick ones for
Dr. Hallock. It's a geometry question. As I look at
the leading edge or carrier panel between Panels 6
and 9 and think about a plume getting up against the
spar of the wings, I'm assuming that the first data
they see that's anomalous telemetry is because ambient
air flow through the vent enters the wheel well causes
that and then you burn through cables and perhaps burn
through the wall of the wheel well at some point after
that. Is that correct, or are you guys assuming that
the plume enters the vent in the front of the wheel well? And just how that geometry sets up with where
the best guess is right now that something might have
happened.
DR. HALLOCK: We're actually looking at
both ways. Obviously it's easier for it to come in
through the vent, if it can; but this is a vent that
has a lot of material in it. It's more like a screen
as opposed to a vent itself. Once again, we're looking
at the timing here, when did those sensors go off line,
because that does say that we're in somewhere around
here making contact with the cable and particularly the
cable run that has all of those cables in it.
Now, we're going to have to move
somewhere in order to be able to get to the point where
we have these sensors just beginning to show a small
amount of temperature change where, at the same time,
we know eventually we're going to get a temperature in
there on the order of 3,000 degrees to start melting
this titanium. So right now we have many, many
possibilities as to what it could be; and we can't
narrow it down as yet to saying here's one or two ways
for this to occur.
A SPEAKER: Just a related follow-up.
Given the location of the tires themselves in the front
part of wheel well, I don't understand how the tires get these kinds of temperatures and you didn't see
something earlier. I guess I don't understand the
temperature regime from the front of that wheel well
back to the back, that you wouldn't either blow a tire
or, if you had the plume coming in from the front of
the well, that you couldn't get some pretty noticeable
damage in the rubber. This jet of hot air will bounce
around a bit; but you would see something, wouldn't
you? I don't understand that.
DR. HALLOCK: Well, in fact, you said the
right thing in there. When this plume entered, it can
bounce around. You've got to remember this is a very
rarefied atmosphere still. So we could be having
3,000 degrees at one end, which is melting titanium,
and at the other end we'll have a sensor that doesn't
know much is happening at the point. So you've got to
have enough atoms in here to be able to convey the
temperature itself. Temperature is a quantity that
depends upon having something for it to register on.
You know, maybe you've seen in these
reports where they say astronomers have found a place
where the temperature is 10 million degrees and this is
a place in space itself. Why? There's two or three
molecules moving around with such energy that, yes,
indeed, if you had a thing that those things could hit against, they would register a temperature that high.
So don't think of it as being like heating up this
room. It's very different because there's so few
molecules there that you can get a great gradation
right across the entire area. Yes, it's bouncing
around. We know those kinds of things.
ADM. GEHMAN: And if you were in
attendance this morning, Bill, you recollect that the
reason we spent so much time on the chemical reactions
involved here is because we're trying to achieve an
understanding of how aluminum reacts, beyond where it
melts and beyond where it burns. What we're leading
to, of course, is a scenario in which a new path into
the wheel well could be developed in seconds, I think.
In other words, the normal process, the mapping process
that you would have to have in your mind where heat
enters here 10 feet forward and works its way back
there may not be the process that took place at all.
And we're trying to establish just how rapidly other
kinds of processes can rearrange the inside of the
wheel well and then match up with these temperatures.
Right now we're still at the exploratory stage.
A SPEAKER: Houston Chronicle. My
question is related to Dr. Hallock's. Again, it's this
phenomenon you're seeing in the wheel well and I don't understand whether the escape is because the heat and
pressure built up inside that compartment beyond its
capacity to vent or whether a jet with a force behind
it was actually bounced off of something or directly
pressed against the door to cause this escape.
DR. HALLOCK: I think I can say I agree
with you. I don't know either. That's part of the
problem here, that it can be actually both issues here.
Remember, we talked about before that we still have
that pyrotechnic here, that release that is used to
release landing gear. That hasn't gone off. That
thing will go off at 500 degrees or something. So
here's a place that the upper part of the wheel well,
which if you get something over 500 degrees you're
going to have this pyrotechnic go off, it obviously
hasn't gone off and yet down at the door level we're
finding temperature very warm, enough so that it is
actually finding its way out of the wheel well itself.
Very complex.
A SPEAKER: SpaceFlight.com.
Mr. Wallace, you talked a little bit about the debris
event on STS 112. I believe we were told originally
there was some superficial damage to the solid rocket
booster that got struck. I wonder if you had a chance
to assess that and whether you could derive anything from that impact that might relate to a similar impact
on the wing.
MR. WALLACE: Well, it damaged the skirt
of the solid rocket booster. Foam material Ð and I'm
not really the expert on this and I'll let my
colleagues answer if they like Ð the bipod piece fell
in a trajectory that's quite different from what we saw
on STS 107 and struck the skirt of the solid rocket
booster. Again, it was a foam-covered metallic
surface, I believe, and it put a big ding in it. And I
think part of the problem also was that when the solid
rocket booster was recovered, there was also an issue,
I believe, as to what might have been the extent of
damage from the foam strike and from the water impact.
So, again, our view on that is rather the way that
event was categorized, you know. Was it called an
in-flight anomaly? Actually it was called something of
a lesser degree of seriousness, yet it went through a
fairly thorough disposition process before the
subsequent flights were launched.
GEN. DEAL: I'll just add exactly what
Steve said. It's exactly the same, just different. I
mean, it happened off the bipod ramp but it happened at
31 seconds or so as opposed to 50 seconds later, as our
incident took place. One of the key things we're looking at is what happened subsequently. You know,
this was back in October. There were two more shuttle
flights. What types of decision went on for the flight
readiness review of the two subsequent shuttle flights
to assess that this was acceptable? So that's part of
what we're looking at.
A SPEAKER: Aviation Week. I have a
question that gets to the issue of the earliest events.
Looking at the Rev 14 and Rev 13 master time lines at
about 25 seconds after start of peak heating Ð and
that's overall at 13:51:19 Ð we have remote sensors
indicate off-nominal event, earliest known event. The
question is: What was the event and what was the
remote sensor? Was it a VSP missile warning satellite
or another optical spacecraft sensor? What was the
event and what was the sensor?
ADM. GEHMAN: I don't have my time line
in front of me, but let me just say between Rev 13 and
Rev 15 the first off-nominal event changed.
A SPEAKER: I see the gradient of issues
there.
ADM. GEHMAN: Plus, they now have put an
aero event. The elevon trim event, I think, has been
moved up. But the first off-nominal temperature event
was upper-left brake sensor temperature rise.
A SPEAKER: I think the operative words
there to the question are "remote sensors indicate."
So this is something is seen that is not telemetry; and
the time there is 13:51:19.
ADM. GEHMAN: Okay. Then I'm not
familiar with the entry then and I wrote Ð you're
referring to what was a remote sensor?
A SPEAKER: Both. What would be the type
of event that was registered on the remote sensor, and
what was the remote sensor? That was well out over the
Pacific.
MS. BROWN: We can get back to you on
that.
DR. HALLOCK: I know where you're
referring to. I know where it is on the time line and
I even tracked out what sensor it was; but I do not
remember, sitting here.
MS. BROWN: We can get back to you.
ADM. GEHMAN: We didn't bring our time
line with us.
A SPEAKER: National Public Radio. I
have a general question and a specific question. If
you reflect back, please, over the last two days here,
what have you learned? How has your thinking been
refined by this exercise in understanding these rather complicated elements of physics and aerodynamics and so
on? In particular, what do you make of the sensor
readings that are around the vent lines, far away
from Ð in front of the wing, which everyone is saying
today, "I can't explain it by my theory, can't explain
it by our calculations and analyses"?
DR. HALLOCK: One thing I've looked at,
trying, once again, to do the answer analysis, work
backwards, how would I get something in that area that
would possibly raise the temperature. Whether this is
what happened or not, I have zero idea at this point.
However, suppose you do have a shock wave up closer in,
much higher up in here, so where the wing is actually
starting to come apart earlier. If you do get
something like that, you can get a vortex that's here,
as you heard Dr. Bertin talking about, which could then
be coming up here and actually pulling off some of the
blankets here and hence allow temperature to actually
be sensed in that neighborhood as going up. Whether
that's what's occurring or not Ð I mean, that's the
only way I can rationalize it myself.
A SPEAKER: But the temperature goes back
down again.
DR. HALLOCK: That's correct. Once
again, you notice things are moving. As soon as you start moving the craft one way or another, whether it's
a yaw or side slip, that's going to move the central
point of where this thing would be impinging on here.
You've got to ask the question. We see all these
events from California on, lots of things are coming
off. What can be coming off such that the people on
board and the people on the ground, watching it, not
know that? Well, there are things along here, things
like the blankets here and the white tile on the top of
here are such that you probably wouldn't notice that
that's what's happening if those are the things that
are actually coming off. So it's trying to say how do
I explain it. Now, how do I get that to happen? I
don't know. At least there's one way to try to explain
what is the event, how do you get that event to take
place.
A SPEAKER: Could I ask a more general
question?
MS. BROWN: One each right now.
A SPEAKER: Well, I have a clarification,
then. ABC News. I want to just clarify, Dr. Hallock.
You are convinced that titanium uplock, that that
damage was done while the shuttle was coming back, not
after breakup, correct, because it was inside the well
wheel and you know that the door was still on? Is that why you're convinced of that?
DR. HALLOCK: 99 percent convinced.
A SPEAKER: My question is that there was
a published report that there's some particular
interest in whether a carrier panel may have been
missing, and there's some focus on that. Is that true
and can you talk about why you're looking at that and
whether it holds any more interest than anything else
at this point?
DR. HALLOCK: You've got to remember
where the carrier panel is. The RCC panels are the
things here on the leading edge. The carrier panel is
that panel that's right behind it that transitions from
there to the tile. In fact, the carrier panel actually
has tile on it. So the question is maybe it's not the
RCC that actually came off for the initial entry of
this but what came off would be that carrier panel.
When you look at the film looking at the foam where it
struck, it struck in this area and it struck in the
area of the carrier panel. So eliminate that.
The next thing why I think it's important
to look at it and we're waiting for what General Deal
talked about is what was this thing that we saw on that
Day 2 of the mission. That could conceivably be a
carrier panel. That's about the size of what we're talking about, as well as what's called the horse shoe
collar that's right behind it. If the carrier came
out, that horse shoe collar may have become loose and
come out. So there's two objects which seem to be
about the size of what may have been detected on that
second day. That's why we talk about it and having it
as being a key thing. If the carrier panel came off,
then it would be very easy to have damage occur such
that the RCC panels themselves would come off. It's
only held on, I believe, with two bolts. Get this
thing out and get some heat in there in the right place
on those Inconel bolts and it could come loose. And
that's what could happen is all of this stuff is
starting to open up into a larger area. We know it's
got to be Ð as we saw from the Langley test, one
thing, one RCC or one carrier panel is not really
enough to really get all the temperature in. So we
need more to happen, but that's one way to get this
thing to start.
A SPEAKER: New York Times, for anybody
on the panel. What is the state of your thinking about
whether the shuttle should always be photographed on
orbit and whether it should always carry or have the
ability to do repairs in orbit, given that all
remaining shuttles are now always flying to the space station? Hal is smiling.
ADM. GEHMAN: Well, I would say you're
asking us for a conclusion that we're not ready to come
to yet. I mean, all of those are relevant and
pertinent questions and we'll address them, but I don't
believe that we're quite ready to make a conclusion
yet. Anybody else can chime in if they want.
GEN. DEAL: Sounded good, sir.
ADM. GEHMAN: I think that you're asking
a question which is a bit more definitive than we are
ready to make right now.
MS. BROWN: I'd like to take a few
questions from the phone bridge.
A SPEAKER: Admiral Gehman. NBC News.
I've been asked this question by several people during
the past six weeks since the accident took place. As
you mentioned a while ago, NASA's doing its own
investigation; and, of course, you're doing yours.
What if both of you come up with different answers?
What happens?
ADM. GEHMAN: Well, there's only one
investigation, and that's ours. All the NASA people
work for us. It is entirely possible that in some
minor detail or some technical detail we may come to a
different conclusion than the NASA management comes to, because we're using the same data. We're all using the
same data. We also may come to a different conclusion
as to the significance of what this piece of data
represents. That doesn't bother me in the least. I am
not going to be influenced by their opinions, but they
will be influenced by ours because our report will be
the basis for the debate about how to fix these kinds
of things.
As you are aware, our report does not go
to the NASA administrator; it goes to the White House
and to the Congress, as well as the NASA administrator.
The implementation of our recommendations will be the
subject of an intense public policy debate by the
government. It might will be that, as Steve Wallace
has indicated so clearly, we aren't going to be the
adjudicators of return to flight but we will make
recommendations as to the parameters of return to
flight and those parameters might be too expensive.
MS. BROWN: Phone bridge.
A SPEAKER: Los Angeles Times. I'd like
to ask a question about the foam versus
micrometeoroids. If your research would ultimately
indicate that a foam strike from the external tank
could have damaged either the tiles or the leading
edge, do you have a methodology for determining that it wasn't a micrometeoroid or, vice versa, if you
determine that it could have been a micrometeoroid, how
could you eliminate the possibility that it would not
be a foam?
DR. HALLOCK: I don't think we're ever
going to be able to say absolutely 100 percent this is
what it was or zero percent this is what it was. We're
going to be looking at what's the preponderance of the
evidence. As I say, so far, looking for
micrometeoroids, I'm not seeing any indication. If I
don't see any indication, looking at all the rest of
the data, in my mind I'm going to assign that a very
low probability. Is it zero? I can't say it's zero;
but I can certainly say it's very, very unlikely.
MR. WALLACE: I'd like to add to the
answer. In terms of our final product, it happens in
the civil aviation realm occasionally that the probable
cause of an accident is not determined to a certainty;
and the NTSB, in fact, sometimes couches their findings
as more in terms of the most likely cause. So I think
the ultimate objective of an accident investigation is
to learn everything you can and go forward and make the
system safer. So I think that even without an absolute
certainty in an ultimate probable cause finding you may
still have a very clear direction on improvements you can make and causes that you can eliminate, even if
they are not established to a certainty.
GEN. DEAL: I'll underscore what
Dr. Hallock said. We will never know 100 percent for
sure that there were not micrometeoroids, but we have
looked at previous shuttle flights where they mapped
out all the tile damage and their have been
micrometeoroid strikes. We also know that's there's
national, international, university type resources that
look at meteorites and we know about meteorites that
fell during the orbits of the Columbia that weren't
anywhere near. So we know it's not a major meteor.
I'm not sure we'll ever be able to rule out a
micrometeor, but we also know that previous shuttle
flights have sustained them and come back perfectly
fine.
A SPEAKER: Discovery Channel. My
question is for Admiral Gehman. This follows along
pretty much where you all have kind of headed in the
last few questions. Do you intend, if you cannot
determine with 100 percent certainty, which is very
unlikely, given where the accident took place and all
the variations and permeations that could have happened
to various components on their way down, do you think
that at the end, when all of this is said and done, that you will posit several scenarios, perhaps with a
probability of each one occurring?
ADM. GEHMAN: Right now, based on the
amount of evidence which is still flowing in, my
confidence is still pretty high that we're going to be
able to ascertain the root cause of this with some
amount of certainty, not absolute certainty; but right
now I'm not at the point where I have any view that
we're going to end up guessing at this or even coming
up with a number of possible scenarios. And that's
based on the fact that evidence and information is
still arriving daily and aircraft accidents with less
data than this have been solved before. So the debris
is still showing us things. We're still learning from
the debris. We're still squeezing data out of the
telemetry. So I'm not at that point yet.
MS. BROWN: Anyone else on the phone
bridge who has a question? Okay. Then we'll drop out
the phone bridge and take just two more questions here.
A SPEAKER: Newsday. I guess I'm still
interested in Admiral Gehman mentioning this
possibility of opening up a very rapid pathway to the
wheel well. Does that necessarily require explosive
burning of aluminum? There are some who are skeptical
of that because you are essentially trying to get a fuel-air type of explosive with an even distribution of
particles. In the chaos of what is going on in there,
it seems that might be unlikely.
ADM. GEHMAN: You're right. What you see
is us trying to characterize that environment; and the
more we learn about how aluminum operates in these
superheated temperatures, the better we'll be able to
characterize that. But what is unfolding here is a
scenario in which particularly a superheated air plume,
a superheated plume of extraordinary high temperatures,
above 3,000 degrees, could kind of carve its own way
into the wheel well pretty rapidly. Now, we're going
to have to characterize that a little bit better. Then
also the fact that above certain temperatures, the
aluminum actually becomes a fuel. It ceases to be a
barrier and actually becomes a fuel. So this presents
a new avenue for heat to get in, and we haven't
characterized it completely yet. I mean, you're
absolutely right. In order for burning to occur, you
have to have oxygen. There's not much oxygen up there;
but if you have a stream of even rarefied oxygen that's
traveling 15,000 miles per hour, you can get a lot of
oxygen molecules in a few seconds. That's what we've
got to characterize.
MS. BROWN: Last question over here.
A SPEAKER: NBC. Dr. Hallock, the issue
of the object in orbit on Flight Day 2 possibly
conceived as being a carrier panel. Can you imagine
any scenarios in which pieces like a carrier panel or
an RCC panel or something else was damaged during
ascent but then remained on for the rest of ascent and
somehow worked loose in 24 hours in orbit? Any idea
how that might have happened?
DR. HALLOCK: That's also one of the many
scenarios we're thinking about on the same thing. This
was pointed out to me very clearly by the astronaut who
has been working with us, Mike Bloomfield Ð that is,
the first 8 1/2 minutes of going to orbit is a wild
ride. You are shaking around with 3 Gs and everything.
I'm surprised a lot of things don't come loose when
you're having something like that. From there on, it's
basically a very mild environment in terms of
accelerations upon you. So there are other things you
can worry about Ð as you say, things like carrier
panels and closeout panels and a lot of other things
that could possibly have become loose, whether it was
initially caused by this jarring caused by the foam
hitting or whether it's something else. So you have to
keep an open mind there. There's some other pieces
that are on other places here which may have been able to move about for a while and then suddenly, when you
started getting in this heating environment, then led
one thing to another to another, falling dominos type
of thing, to a lot of other possible scenarios.
A SPEAKER: How would it come loose after
4 hours, though, with practically no forces in orbit?
DR. HALLOCK: Think of what you also
have. You have a very interesting heating environment.
You spend Ð I don't remember the exact time. Was it
90 minutes you're in the very cold of space, where it's
minus 250 degrees, and the next 90 minutes you're in
sunshine where it's plus 250 degrees, whatever the time
is Ð 45 and 45. I knew 90 was in there somewhere. I
could calculate it. So you're having extremes. The
temperature extremes, plus and minus 250 degrees
Fahrenheit, do things to materials like metals.
GEN. DEAL: Plus some maneuvering of the
shuttle.
ADM. GEHMAN: It turns out that just
before this thing was spotted, they had just done a
state vector change. They had just done a yaw; and if
you've got no gravity, even a small motion like that's
enough to throw something off. Astronauts have told me
that on Day 2 or Day 3 of a flight, they look out the
window and see a washer floating by. I mean, things happen. I'm not so sure we're going to have to prove,
you know, exactly how this happened.
MS. BROWN: Okay, everybody. Thank you
very much. We'll see you next week down at Kennedy.
(Conference concluded at 2:16 p.m.)
Back to Event |
|
|
|