Columbia Accident Investigation Board
Home Board Charter Board Members News Photos Events Contact The CAIB
Columbia Accident Investigation Board Press Briefing
Tuesday, April 22, 2003

1:00 p.m.
Hilton Hotel
3000 NASA Road 1
Houston, Texas

MS. BROWN: Welcome, everybody. We're ready to begin, and let me turn you over to Admiral Hal Gehman.

ADM. GEHMAN: Good afternoon. We'll use our usual format here. As the regulars are aware, we don't save up our news for Tuesdays. This is really an opportunity to dialogue with members of the board. That's what we'll do today.

I have a couple of odds and ends, and then I'll turn it over to my colleagues here to my right. First of all, in the world of debris picking-up, the total as of April 16th, which is the last report I have, we had picked up 72,750 pieces of debris total, for a total weight of 79,900 pounds – about 36 percent, by dry weight, of the orbiter.

I think, as we announced last week, the board has approved NASA's plan for how to terminate the searching. We still find interesting pieces of debris. As a matter of fact, we were just talking about an interesting piece of debris that's just recently been found. So the debris search is still very important to us.

We're beginning kind of a new phase in the board's work. We're beginning to concentrate on the report. We're beginning to think about integrating some of the facts and theories and scenarios and analysis. We're beginning to analyze some of the interviews that we've conducted. This will take a couple of months; but a manifestation of that, of course, is the fact that we, last week, issued our first two interim findings and recommendations. They were released last week. You're all aware of those.

As the board deliberates more and reviews what it is that we know and what it is that we don't know and what it is we're going to have to go and do and what kind of work we're going to have to pursue in order to change one of the "I don't know's" into an "I do know," more of these interim recommendations can be expected. Once the board is satisfied with a subject, we will release it. We are not interested in surprising NASA at the end. If there's something that NASA can get to work on, we want them to know about it as soon as possible. I don't have any particular projections as to what the next recommendation will be, but there are four or five that are milling about.

Just to give you an example, I mentioned last week that the board had approved the closeout of two of the NASA fault trees. When we do that, when we go through the closeout of the fault trees, we frequently find interesting observations, we frequently find things which the board wants to note, and we may put those in the category of observations rather than findings and recommendations, but we're doing that all the time.

I will issue my first but not my last "no comment" on the press report that Mr. Dittemore intends to resign.

I would make one other comment by way of clarification – just so that, when you hear terms, that we are both using the same terminology. The board is going to attempt to structure the report in terms of a direct cause of this accident; contributing factors – and a contributing factor would be one which we would hope we could tie to this accident; and then a category of items which we would call root causes – these are cultural kinds of things or historical kinds of things or budget kinds of things that you can't tie directly to this accident but we feel in some way or another are related, distinctly related; and fourth would be a category that we call significant observations. A significant observation is something that the board has come across that may have nothing to do with the accident of the Columbia but it might have to do with management or safety or something else and we feel NASA would benefit from us noting it. So those are the four categories of things. So when you hear terms thrown around, try and couch it along those lines.

Okay. That's enough for me. I'll turn it over to my friends over here. First of all, from Group 1, Admiral Turcotte.

ADM. TURCOTTE: Good afternoon. From the maintenance, materiel, and management group, I would like to give you a short update of a couple of issues I addressed last week – one, on the dissection of the foam and some of the anomalies we found and, two, some of the RCS testing.

First a report on my colleagues. General Deal just returned from Michoud. He was there last week during all of the dissection; and General Barry today is at Kennedy, looking at the debris field and doing some other work.

The next slide, please. As I talked to you last week, we had dissected ET 120 and found some anomalies. This week we had the opportunity to look first at the closest sister tank, ET 94. You recall Columbia had ET 93. Again, here's what we're looking at, the bipod foam. There's the first analysis where we found several electronic anomalies.

Next slide, please. Then I'm going to show some examples of some of the anomalies we found. We found a total of 74 observations on this sister tank. You can see some foldover with some other debris in there.

Next slide. You see some voids. A little bit bigger than what we found on ET 93. More volume. Bigger void.


ADM. TURCOTTE: I'm sorry. ET 94. I keep doing that.

Next slide. Then again you can see some more voids. Much bigger volume and a little bit different patterns that we found on ET 120.

Next slide. Under the radar cross-section. I reported last week that we had submitted a T seal; and, again, that's what a T seal looks like. We showed a cross-section last week. We got the results back. We found that that T seal that we did submit passed both the radar cross-section and the signature ballistics required that was tracked upon re-entry. So that did correspond exactly with what we saw on the duration of the mission.

That concludes my remarks.

ADM. GEHMAN: Group 2, Steve Wallace.

MR. WALLACE: Good afternoon. I'm going to talk quickly about training. We haven't talked much about training during the course of the investigation, and it is an issue that we are fairly close to concluding an actually very extensive, although fairly low-profile, assessment of the training program. I'll talk about training briefly in three different pieces – the training of the astronauts, the training of the mission control personnel, and the training of the launch control personnel.

The astronaut training actually went on for 126 weeks. Because of the very extensive repeated delays of STS 107, their training was dragged out over a period over twice as long as what might be typical. 5,000 cumulative training hours for the crew. A lot of these are integrated training exercises with the mission controllers and the launch controllers, and they do a certain amount of retraining. When they have long slips, they also will go into sort of a maintenance level training and then re-peak up again before the mission. Really the crew records of training was all in perfect order, and all of the evidence indicates that the crew was extremely well trained for the mission and that crew training was certainly not a factor.

The mission control team training. There were actually some discrepancies found, which we would probably characterize as an area for improvement – that is, that 7 of the 77 mission controllers involved in the mission actually had some recertification requirements missing. Now, not to overstate this, they were actually highly qualified, in our view, for the mission. Nonetheless, there were some recertification requirements, exercises that weren't completed; and these discrepancies were not drastic in the preflight control process. So there's an issue there that I think the board will speak to as something for improvement, but clearly not in any way considered to be a contributing factor.

The launch control, which is a group down at Kennedy, that part of the training is still being completed. So assessing all the records there.

Our two big issues that we always talk about, sort of the foam story and the DOD imaging story, which really is the focus of a lot of the energy of Group 2. I think I'd like to discuss a little bit how these stories fit together and, that is, the foam story, which is all of the prior foam events, the disposition of foam events, and particularly the most recent prior to 107, which was the STS 112 event. We see in the documentation and we see in recordings "not a safety-of-flight issue." "Not a safety-of-flight issue." That same expression is kind of the same drumbeat we hear in the decision-making regarding not ultimately requesting utilizing imaging assets that might have been available during flight. So that's sort of the common thread and, indeed, the part of the story that pulls those issues together.

All three of the members – my colleagues, Dr. Sally Ride and Major General Hess – we're all very much focused on that. It's probably the bulk of what we are working on, looking at all these various processes of the boards and particularly – it's easy to look back at these things; it's hard to look forward and envision a process where that sort of thing, where you can eliminate it. I know that some of my other colleagues have drawn the comparison to the Challenger situation and how an organization that is so effective and has such thorough processes, these breakups can still occur.

Other than that, we're also following return-to-flight issues. NASA has, of course, extensive efforts going on in that area. We did issue our first two recommendations, as Admiral Gehman referred to. They were both characterized as return to flight. In other words, all of our recommendations ultimately will not be that way. There may be some longer-term organizational-type recommendations. However, the first two issued, the one on the inspection of the RCC panels and the other on use of imaging assets, both were prefaced with "before we return to flight." A number of our recommendations will be that way, and a number will not.

NASA has, again, extensive efforts that many of ours will parallel and there won't be any contest there. I will say that the RCC recommendation was something that NASA did not have on their return-to-flight agenda directly; whereas the other one on imaging, they had several different imaging efforts underway. So we'll be following those issues and issuing further recommendations in that area.

ADM. GEHMAN: Thank you very much.

Dr. Hallock.

DR. HALLOCK: Good afternoon. I'll be talking about the work that Group 3, which is the engineering and technical analysis group, has been working on; and we've been quite busy of late. We've been looking at everything from the OEX data to aerothermal analyses, looking at the debris and trying to analyze what it is we're seeing with the debris, and also getting ready for the tests that will be coming up shortly at Southwest Research.

My colleague, Scott Hubbard, that's what he is working on at this point, is helping to finalize the test plan. I believe the idea is to start testing next week. They will be starting with the main landing gear door and looking at the tile on the door itself as a beginning. A lot of that's going to give them a chance to shake out the equipment and so on, as eventually we'll be moving on from tile to the RCC panels themselves.

Doug Osheroff is actually down at Cape Kennedy. This is his first chance to visit down there. He has been working on the role of the chemical effects in this superheated air environment, which is interesting because not only do you have to worry about how everything is flowing but the environment in which you're operating is very important in the sense of you don't have an oxygen molecule, you have maybe an atomic form of the molecules instead, individual atoms, and hence they react a bit differently. He's also spending some time thinking about possible new ways of doing some non-destructive testing because obviously that's going to become a very important issue with respect to things like the RCC.

Sheila Widnall is continuing the work she reported on the last time she was here. That is the aerodynamic responses to all of these extreme heating events. It's not a very simple area. In a lot of places, some new ground has to be broken in order to be able to understand the effects that we are seeing.

Also, my colleague Roger Tetrault is also down at Kennedy and will be down there all week.

A lot of new things are coming in in the sense of results from chemical analyses and X-ray studies. Part of what we're really interested in is when you see this material that's on all of the equipment down there, called slag anomaly, the intent is to find out what is it made of because if you can determine what it is made up of and map that with the idea of what the temperature would have to be for such a thing to melt, you then can get a sense a little more of what is really going on, what is the temperature environment and also where is this material possibly coming from.

The main area, though, a lot of us are now starting to look into is this whole idea of taking all of this evidence that we have – that is, the telemetered data, the debris analysis types of things, the OEX data that we talked about, the videos, the timing of events and so on – and trying to put all of these together and try to come up with some hypotheses as to what happened back on February 1st.

You sort of take an event, such as a broken T seal or something like that, and starting from there, start looking at all of this data and see if you can actually tell a story. The problem is getting through a lot of it. We've been working on things; the NASA folks have. On Thursday of this week, the board will be meeting with NASA to exchange some ideas and actually some hypotheses also. The intent, as I say, is to share this information because we're all trying to get to the same result – that is, what did happen back on February 1st.

To develop these hypotheses, it gets very important to really understand the nature and how these sensors behave – and not only how they behave but how do they fail. I've been working very closely with Professor Bruce Starling from the University of Washington, who is helping us to look at the sensors themselves, how do they actually work and then what are the failure modes of doing it. What I'd like to do is to show you some OEX data here but more in the sense of trying to say that we've got to understand what is actually going on.

The data itself is interesting but you have to, as I say, first spend the time to understand what is it you can say or not say about the data. So we have various kinds and types of things. We have a lot of the data which is what we would say is nominal flight data – in other words, it looks just like data that occurred on the last five or six flights of Columbia. So here what we're seeing in various colors are previous flights of Columbia and looking at whatever this happens to be. This happens to be the left OMS pod, which is an important issue for a lot of what we're looking at. The types of things you're looking for is where does it differ from most other flights.

As you can see, we are talking about something happening here. Normally everyone seems to get excited about temperatures rising and rising a lot. Well, here we're interested in the fact that it didn't rise as much as it did on previous flights and that says something, but it also says sometime later, at 540 seconds after, it started its re-entry thing. Then temperatures did start changing and changing a lot and doing a lot of different things at the time.

Go to the next one, please. Here's another one which is going to be interesting, which is the front spar panel. Now, this is fairly simple; but you've got to be careful of how you look at it, in the sense of you do see a small beginning of something happening and then it goes fast and it goes way up here. Some people at times will say we've reached a temperature of 450 degrees. Well, it turns out this sensor, by the way, is calibrated such that the highest temperature it will ever show you is 450 degrees. So you have got to be careful about trying to take that number and doing something with it because in this case it's actually started rising faster and faster and, in fact, it was going so fast it got overloaded and eventually the sensor itself failed. So you have to look at how they do it.

One thing I forgot to mention is that these times are very interesting. The good news is that all of the data that we have, the telemetry, some of the data we saw many months ago when we first started to meet, showing, you know, temperatures changing inside the wheel well and all of that, that was a different data system and the OEX is a completely different system, but the good news is they're all using the same time base. So when we start putting the data and looking at them together, we can feel fairly confident that the time is what it says it is. So when we say something may have differed by 5 seconds or something, we're fairly confident that that can be used as part of our investigation to understand what is going on.

Next slide, please. Here's another one where different types of things are going on and lots of stuff. Here's a case where some of the previous flights had one sort of response and others had a different type of response, but in this one it's another one where you start seeing things happen but then suddenly it goes down to zero and in this case starts vibrating like mad. Well, these are cases where we're talking about the sensor itself probably melting or the wiring next to it at the time.

Next one, I think. Here's another one which we've seen a number of times in the data where it goes along and then in the space of one time increment, a second, something jumps up something like 300 degrees. Some people may try to look at this and say, wait a minute, look what happened, we have something that's 300 degrees hotter. Well, things like this can happen; and in this case it probably happened back at the source of power for this particular sensor. As it works out, it's just one bit. As you know, the data is transmitted as a series of bits. It starts off as 10 bits and as 8 bits. So what is happening is one of these bits – and I think it's the fifth one – actually just changed in magnitude because of what was going on because of a problem in the electrical power supply, which in itself was probably being affected by the temperatures that are going on.

So the point I'm trying to make, there's a lot of things we need to look at which is sort of more the unglamorous part of all this – that is, to really dig down and understand how the sensors are operating and what kinds of failure modes they can go into. So some things tell you that the S temperatures are rising, but the other part we need to understand is was it with the wiring.

Another part of this unglamorous part of the thing is that we've been looking at all of the closeout photos. These are photos that are taken just before they start buttoning up the shuttle itself and getting it ready to move to the launch pad area. They take photos of everything. So now we can see here is where that sensor is and here are all these cables. So we take those and the engineering diagrams and try to track down, okay, where is that wire. Okay, here's a wire that obviously got burned at such and such a time; and here's another one that did at the same time. Well, let's now look at it and see are they in the same wire bundle or not, or is there someplace where they at least come together so we can say that's probably where the heating event occurred, rather than just hitting the sensor part itself.

So there's a lot of these kinds of things that need to be looked at and we're spending a lot of time on it and, as I say, it's important to understand these things because, frankly, I've heard a lot of statements people are making which are wrong because they're trying to draw too much from some of these sensors, such as like the first one I showed. Someone could say, gee, it went up to a certain temperature. Well, it could be more; but that was the highest that it was set for calibration and it just happens to be that where you're plotting just happened to be a larger number of degrees that it could have plotted but it was not part of it.

One last thing that we've been doing is we've always said many, many times – and could we have the next viewgraph, please – that the debris is telling us a lot. We've shown these pictures and we've seen a lot of things showing what happens to the debris. Well, another interesting part of that is to go back and look at where did we find all of this debris. And I've filtered out a lot of the information so all I have on this particular one are just the RCC panels – not the sides part, not the mounting brackets, just the panels themselves. It shows a very interesting thing. You can see here's 9. Here's 8. There's 7. Here's 6 and so on. All of it seems to show this thing. I mean, it shows that things were coming apart when this happened in somewhat of an order centered somewhere about 8 and 9, because that's another thing we've been looking at. The higher-numbered ones also showed somewhat the same thing, not as clean as this particular one; but it does, once again, give you another feature of things to look at as you're trying to develop all of these hypotheses.

That's what I have.

ADM. GEHMAN: Thank you very much.

MS. BROWN: I think we'd like to take some questions now, and we have a phone bridge we'll take questions from after that. First we can take them from the audience starting over here, geographically. Mic on the end, please.

A REPORTER: Orlando Sentinel. My question's for Admiral Gehman. Could you talk a bit about the status of the investigation, big picture? What are some of the big questions that you feel are still unanswered, and what is your timetable right now? Do you have target dates for when you would like to be completed, when you would like to be finished with the hearings, when you would like to start writing the report, when you would like to have a final report done?

ADM. GEHMAN: The progress of the investigation will be event-driven. We will progress ourselves depending on how we develop the investigatory matters. The best I can tell you is, in broad terms, we have agreed with NASA that the main effort or the search for debris will end on the 30th of April, even though the analysis of the debris will go on for weeks after that. The OEX data, it will take another two or three weeks to complete the analysis of that; and that will be finished in early May. The foam testing will go on in May, the impact testing of shooting foam at various wing parts. The testing that we're keenly interested in – that is, shooting at the leading edge – won't even start until mid-May. So you can see that we have another few weeks in which we'll still be receiving data; but sometime in early May I expect that the rate at which new information is put on the table will start to fall off. The board is already beginning to deliberate a little; and in the month of May we will spend more time deliberating and less time investigating, I suspect. That's really about the best I can do, as far as predicting the future.

I, as kind of the traffic cop of this board, am pushing certain administrative processes amongst the board members to write things down now and begin to write down some preliminary kinds of things; but this is a very, very, very beginning of that stage. Since we're still receiving new information, it's a little bit early for us to think about concluding this.

We are still interviewing people. We have well over a hundred interviews done now. We have some more to go, and we have a couple of issues that we're just at the front edge of examining. We are going to spend a considerable amount of time starting tomorrow, as a matter of fact, and continuing on to next week, conducting kind of a board awareness program of high-reliability and high-risk organizational management issues. We feel a little bit hesitant to comment upon NASA's management style and technique, in a very, very risky business, without baselining what the academics and the professionals in that area say about it. So there's an area that we're just starting to get smart at.

So the way I would characterize it is that we are in the declining weeks of receiving new information and we are in the beginning weeks of the deliberation and writing phase.

A REPORTER: CBS News. For Admiral Turcotte, I think. Your chart on the radar cross-section analysis issue lists the RCC T seal and a wing leading edge earmuff insulator. Did you guys test a partial RCC panel? I'm assuming that got ruled out. Did it? Also, the wing leading edge earmuff insulator, can you explain is that even theoretically possible, because that would have had to have come out of the interior of the cavity? I'm just trying to figure out where that plays into this.

ADM. TURCOTTE: First answer is we have not tested partial pieces. We are looking at that now. We are looking at perhaps taking some pieces of debris and looking at the size and whether it would match both the ballistics and an RCS and submitting them for tests. So that's the next phase of this.

Two, the earmuff? No. It depends on the scenario. If you rule out a panel, there's no way for that earmuff.

A REPORTER: That's what I thought.

ADM. TURCOTTE: So if you're just in the T seal business, there's no way for that thing to get out. But it did match – you know, you had to cover it because it matched both the ballistics and it matched the cross-section.

A REPORTER: Florida Today. For Dr. Hallock. I was very interested in the slide you had up there with the RCC panels and where they were found on the ground, and I was wondering if you could comment on what that data appears to be telling the board.

DR. HALLOCK: Well, it's something we're still looking at at this point, but one clear thing that we can see from all of this is what I just showed you here is the left wing, that the pieces from the left wing fell well before the pieces from the right wing. In fact, if you sort of average – and what we try to do is sort of find what's the center of mass, if you will, of the left wing pieces and the right wing things, they're separated by something like 60, 70 miles. So obviously things were coming off of the left wing first. So that's one part of it that's of importance.

The other part of the pictures I showed – it's up here again. You can see way off the furthest west that we have is something like around No. 9, where there's an upper piece of the RCC panel. Basically when you come to the right here or you're going to the east part of it, like I say, not only does it seem to be going down – 9, 8, 7 – but the other way, too – 9, 10, 11, 12, 13. So things are coming apart from the middle, if you will. So those are two very useful pieces of information.

A REPORTER: Washington Post. This would be for Admiral Turcotte or Dr. Hallock, I think. First, could one of you, for those of us in the provinces, define "earmuff insulator." And could you tell what Dr. Hallock called a story about, if it's the T seal, then what would be the sequence and what are the biggest "I don't know's."

ADM. TURCOTTE: (To Dr. Hallock) I'll take the earmuff part, and you can go from the scenario.

Essentially, it's a heat dissipater. It is a blanket that is put behind the actual panels, the RCC panels, to carry heat. That's really its sole function there. Between the panel, as you've seen in the many pictures, the RCC panel, the shape of it's kind of like this, and then you have the leading edge of the wing. This blanket is in between. So it helps carry the heat so that it doesn't radiate towards the wing leading edge.

DR. HALLOCK: In terms of the scenarios or hypotheses that we're trying to come up with, we'd have to take a number of things that we would say as let's try this as being the place where the breach occurred; and then when you look at that breach, you then have to look at all of the evidence that you have around it. Can you now explain each of the temperature sensor types of things that I showed or each of the wires being severed? Can you explain the slag? Why is it so thick here and nothing is over here? You even look at the pieces you have because there's also the issue of why don't you have a given piece. So it's trying to put all of those things together into hopefully one picture. So what we keep doing is starting at different places and saying let's pretend it was Panel No. 8. Okay. If we take that and somehow it got in through there, now is everything consistent with some large temperature source being introduced at that particular point? You have to then look at all of the RCC panels in another way because it's basically an open channel at the very front of these things. So actually in some cases you could – and have the hot air come in one place and start moving to other places. Do we see any evidence of that happening?

Also the other thing is when you start looking at all of this slag on the backs of these panels, what is it made out of? Is it aluminum? Well, then that's maybe we're seeing pieces of the spar being burned up. Does it have other things that tell us that maybe it's Inconel, which are the bolts that are holding these things? So each one of these things, you sort of have a methodical way that you then start going through each and every possible thing to try to walk from wherever we say the initiating event is, all the way to eventually get back to things that we talked back many weeks ago – that is, we had a very hot source of heat somewhere in the wheel well and how do we get it to there, among others.

A REPORTER: I was hoping you would focus on just the T seal scenario, if that was the thing that came loose on Day 2, as you've now matched it.

DR. HALLOCK: I don't know if we say we matched it. We say that a T seal is consistent with what they saw. Doesn't mean it couldn't have been something else. But if you have a T seal that now comes out, now you're talking about having a rectangular orifice there, so to be something that's maybe 3 quarters of an inch wide, an inch, and it could be 10, 15, whatever number of inches long. Now you start talking about if this is now open, now what happens. How do you introduce the air through that and what kinds of plumes can you form on that?

The point is you start with that and now you're saying, okay, if we can introduce the air and it will be introduced over time and slowly start building up, what happens? That heat has now gotten in there. What can it do to go anywhere? A lot of these things were designed to allow the panels, for example, to radiate away some of the heat. If you have a place where the heat is building up and the temperature's getting hotter and hotter in there, how can you re-radiate that?

So the whole point is to start off with something which is a narrow slit and see how can that now build, what are the ways to build? So you can build it by bringing in the heat panels nearby, because of the high temperatures, aren't able to re-radiate a lot of that heat. So maybe now the next thing would happen is you would lose probably the bottom of one of the neighboring RCC panels. Now you have a large orifice and hence you can now introduce lots of more molecules. Remember, it's a very rarefied atmosphere up there. A lot more of these molecules and atoms of high temperature. Now you can start talking about a lot of these heat sources coming together or even spreading apart but some places concentrating on areas and actually burning through the lower-temperatured items like aluminum. You know, the aluminum, if we're looking at that spar, that's right behind all of this because it's out of aluminum and it's one of the things that will melt at one of the lower temperatures. So it's more likely to melt than some of the others. Piece by piece you have to make arguments about how do I get that hole bigger in the first place, and what I just mentioned was one way you could do that.

A REPORTER: ABC News. Two questions. One for Admiral Gehman. If I understood you right, you said you had an interesting piece of debris. Then I have a question for Dr. Hallock. What data do you have from the OEX recorder on ascent that you've been able to analyze, and what does that analysis show?

ADM. GEHMAN: Well, I was attempting to reinforce the point that the debris collection continues to be important and will continue to be important right up until the end. We have continued to pick up left wing tiles and left wing leading edge component systems west of Interstate 45, which is an area which had not previously been searched; and it all helps. It all helps. That's all I want to say about any individual piece at this time. I'll make a comment about the last question that Kathy asked, and that is that for 11 weeks we have been saying that we don't have any particular scenarios, any favorite scenarios. We used to call them the scenario du jour and everything like that.

As I indicated before and as Jim Hallock indicated, we are involved in a series of meetings right now in which we are going to attempt to arrive at a working hypothesis. So it's a little premature to answer the previous question because we are going to meet with lots of people, and the board's going to deliberate over this. We have a meeting on Thursday, as a matter of fact, in which both some of the NASA team and us are going to meet together, in which we're going to begin the process of trying to come up with a working scenario, which is a change from what our process has been up until recently. But I think 11 weeks into this, it's time that we attempted to see where the evidence was pointing us. We haven't done that yet, but that indicates that we are moving more toward a deliberative end of this investigation and moving away from the evidence-gathering piece. So I wanted to make that comment about Jim's comment. And I'll let Jim comment on ascent data.

DR. HALLOCK: Well, obviously since we have the data on ascent as well as on the re-entry, we'd look at it. And obviously we've been looking right around 81, 82 seconds to see if there was anything there, that being the time when it looks like the foam struck the leading edge of the shuttle. Frankly, I don't see anything convincing there. I mean, yes, you see some very small type temperature changes; but they're almost within the noise, if you will, of the data. So I don't really see anything there. There are some other temperature changes many minutes later; but how I tie that back to an event at 82 seconds, I'm not quite sure.

A REPORTER: Newsday. For Dr. Hallock. On the T seal scenario, in terms of how you would lose that bottom end of a panel. I'm just trying to understand where that plume – I mean, would it be redirected back towards the panel by impinging on the spar, or how would that work? Secondly, is it too soon yet to say whether or not there might need to be a redesign of the T seal?

DR. HALLOCK: I don't know if I can comment too much on the latter part of it, but the former part – remember, what we're talking about here, if it is a T seal here, you have basically a very narrow slit into which the heat can be building up and building up and building up. Remember, at the same time the RCCs, the way they were designed, was to be able to withstand temperatures like around 3,000 degrees Fahrenheit but part of the way they withstand that is being able to pass on that heat and one of the ways they pass it on would be by re-radiating the heat area. And if you have a chamber in here, this very narrow air where all of this very superheated air is coming and collecting, if you cannot re-radiate some of that heat, that heat is going to get so high and collect so much that I think one of the things it could do is then cause part of an RCC panel to basically break off and just separate. At least that's one of the modes that I'm considering.

A REPORTER: Would this have to be a panel that is weakened, or even a regular panel might succumb to that sort of pressure?

DR. HALLOCK: That I can't answer. Obviously if it's weakened, one would tend to think it would break easier. Whether a fresh panel would go through the same thing at this point, I don't know.

A REPORTER: Houston Chronicle. I have a question for Admiral Turcotte. It has to do with the external tank dissection. You showed us in your charts some flaws and voids that you've encountered. Could you characterize for sure if that work was in the bipod area, and how would you characterize the workmanship and the quality control that you've seen from the work so far? Is this troubling? Is this something that you would expect the design to tolerate? I guess I'm asking what you think it might say about Tank 93 on Columbia and any conclusions about the prospect for shedding foam in that area.

ADM. TURCOTTE: Well, the first part of your question. That was from the bipod. It was from the right bipod, which is the positive Y side. Again, as I said, it was ET 94 – the sister of ET 93, which was on Columbia. So we assess that they were very close. They were machined about the same time, made about the same time. So that's why we're very curious to look at that.

The second part of that. That is part of what we're looking at is inherent in the design of that and actually filling the void of that bipod assembly. Is there a better way to do it? Is there no way to do it? Were the appropriate procedures at that time employed or the known procedures employed at that time? All those things we're looking at. Right now that's not known, and that's not really for us also to direct. Part of that, NASA is looking very closely at another design; and they're looking at all of those processes. So it's really inappropriate for me to comment now at this point on the future direction of that. But I can say that it's anomalous, we think, because it was very close to about the same time of manufacture. So one could make that presumption that what we found in ET 94 could have been reasonably found in ET 93, which was flown on Columbia.

A REPORTER: Associated Press. Two questions. The first for Admiral Turcotte, following up on that. Besides voids, did you find anything else? Because we heard about a piece of tape that ended up on another bipod on another tank. So did you find anything else besides voids all over the place?

For Dr. Hallock, the question is the T seal. If the only gap was the T seal and all the panels around remained intact, would just a missing T seal alone be enough to contribute to what happened? So it's two separate questions.

ADM. TURCOTTE: The first part. There were some voids. There were also what were called rollovers. When you spray something like paint, you go back and forth across. The bond was not what it should have been. In other words, it did not adhere as it should have. So as I said, there were 74 observations found last week. Many of them were voids, and some of them were what we call rollovers, where two layers of foam come together and also where a layer of foam is bonded to an ablator or something else that was inside there. So there's other things besides that we did not find on this particular dissection, like we did on ET 120, any foreign objects, to my knowledge.

DR. HALLOCK: The second part you were asking about – are you asking to suppose it was just the T seal and nothing else ever?

A REPORTER: Exactly. Suppose it was just a T seal that floated away and everything around that gap remained intact. Would that be enough to cause such penetration and destruction?

DR. HALLOCK: Interesting question because I have not thought about that, I must admit. Off the top of my head – and please remember this is off the top of my head – I would think you would have to somehow get it to get more of the superheated air to be in. So I think you're going to have to get some other way, whether it's a broken RCC panel or something like that, to get a larger hole there in order to be able to get enough heat to wreak the damage that it did. But, once again, I haven't thought about it but I'm going to make a note about it and think about that some more.

MS. BROWN: Now, I'd also like to remind everybody that just because we're giving you the opportunity to ask a question each, that doesn't give you the license to pile six questions on at once.

A REPORTER: A single question going to two panelists, Admiral Turcotte and Dr. Hallock. There are voids – there are presumed to be voids in this foam that flew. What is the volume of voids collectively, what was in the voids when they broke off, and how does that affect the testing at Southwest Research Institute? Will you be shooting foam with voids in it? Shooting foam with voids fill with air? Shooting foam with voids filled with water? Ice? With liquid oxygen? Solid oxygen? You two have to work together here.

ADM. TURCOTTE: Absolutely. And we do. Let's see. That was six questions?

The first part I'll cover. What were in the voids? Essentially air. They were – whatever was in the room at the time when that was sprayed, they were clear. That was air. But, you're right, at the time there are many assumptions – and I will turn this over to Dr. Hallock here – but there are various assumptions about the cryopumping theory, about the expansion of – you know, when you supercool air – nitrogen turns to gas and then it returns back to – excuse me – to liquid and then to gas. And that causes an expansion. And that is one of the theories of why the cumulative effect of that would cause the bipod to separate from the ET at that point.

Now, over to the testing.

DR. HALLOCK: Well, actually I think you answered my part of the question, too, in the sense that the reason we're interested in the voids is that it does give you the cause that will make the foam break and break off. So it's not that the void is something that we need to officially recreate – at least, I wouldn't think so – for the testing that we're going to do; but it just is the mechanism that allows the foam to break off.

A REPORTER: NBC News. First a question from several weeks ago that we hadn't found resolution to. In testing the candidates for the object on Day 2, you've used the radar cross-section and you've used the decay characteristics. General Hess also mentioned a third observed characteristic of the object, which was its re-entry. He certainly suggested from his discussion that the actual entry was observed by some U.S. asset that provided data perhaps on brightness or on spectrum of the actual atmospheric entry. Was that a misstatement, or is there additional data that you can use to characterize this mystery object?

ADM. TURCOTTE: To my knowledge – I can speak that it was observed, and that's part of where we got the area-to-mass ratio or the ballistic coefficient.

A REPORTER: But the actual entry, the flare, the actual fireball when it re-enters the atmosphere, was that observed by any U.S. asset?

ADM. TURCOTTE: Not to my knowledge at this point.

A REPORTER: My question today involves the debris search.

MS. BROWN: That was the question you get. That was the question you get for today.

A REPORTER: My question from two weeks ago, then, is on the issue of western debris. Is the end of the search, April 30th, all debris search?


A REPORTER: What is your thought with the debris search in Utah and Nevada and New Mexico?

ADM. GEHMAN: No, the April 30th is the end of the search for the thousands and thousands of firefighters out there. Individual searches will go on. There will still be a search headquarters. It will be moved from Lufkin, Texas, to JSC. Individual sightings will be followed upon by a debris team and individual areas, high probability areas, will be searched, but those search teams will have to be organized when we're ready to go out there.

A REPORTER: Los Angeles Times. I have a question for Mr. Wallace. I understand you were careful not to overstate this, but can you tell us a little bit more about the recertification process and maybe give us a couple of examples of things you have discovered where someone at Mission Control had not completed the recertification that you would have liked them to have before the mission started.

MR. WALLACE: Well, they have a lot of training requirements and a number of simulations; and again, there were 7 out of 77 where some of the recertification requirements were not complete. Now, this, I would characterize it as being maybe something that I would characterize as perhaps more serious than a recordkeeping error but not serious to the point that it would call into question their qualifications to control the mission but that certain sort of required drills or exercises were not done. That's about as detailed an answer as I can give you because I don't remember exactly which sort of exercise it was.

A REPORTER: Dallas Morning News. Did I understand you to say, Dr. Hallock, that there were interesting temperatures later in ascent, data from the OEX? You said you didn't think that at 81 or 82 seconds you saw anything really that you could have confidence in; but you said there was interesting stuff later in ascent, right?

DR. HALLOCK: I believe I said there were some temperatures much later where there was some temperature rise. I don't remember what it was – 7-, 8-, 9-, 10-degree temperature changes; but that was like five minutes into the launch.

A REPORTER: What would that mean?

DR. HALLOCK: I don't know.

A REPORTER: Why is it interesting?

DR. HALLOCK: I just said that there were other temperature things; but how that correlates with the situation at 81, 82 seconds, I don't know. And I don't know if it does.

A REPORTER: USA Today. We've seen several reports this week which apparently indicate that at least some folks at NASA are prepared to say now that the breach occurred as a result of the foam in the area of RCC Panel 8 or 9. I just wanted to see if you could help me out, Mr. Hallock, or perhaps Admiral Gehman, and assess – I know you have more work to do on analyzing this – but based on what you know now, is the board in concurrence with that, or can you give us any guidance about how far along you are in making such an assessment?

ADM. GEHMAN: We are not in a position to concur or not concur, because our first meeting on this subject is Thursday. I read the press report that somebody at NASA has a theory; but we are just at the beginning of that stage, as I indicated earlier, of developing a working hypothesis. So I certainly wouldn't comment on that scenario because we're at the beginning of that process.

MS. BROWN: We have some people on the phone bridge. I believe we had a few problems with that early on. Thanks for bearing with us.

A REPORTER: NBC. Admiral Gehman, you made a couple of recommendations last week, one using the spy satellite system; and I can foresee possibly a future shuttle marooned in orbit. Is the board taking a position or will they recommend to NASA that they come up with some rescue scenario that they have on the books, ready to go in case a shuttle should be left in orbit and they can go up and rescue the astronauts, something like we could have had that situation here, had they used the photographs and seen the problem that they had on the left wing?

ADM. GEHMAN: I wouldn't want to predict what recommendations the board may make in the future. I can tell you that the board is going to look at issues such as on-orbit repair, various crew survival escape modes and mechanisms. We're going to look at the relationship of the International Space Station to see whether or not the presence of the International Space Station changes any of the assumptions that were made with respect to crew survival, but to me it seems it's too early to be declarative about what we may or may not recommend. I would say that all those subjects are going to get looked at in an effort to make shuttle travel safer and more reliable.

A REPORTER: Discovery Channel. For Admiral Gehman. Have you caught a whiff of any other ongoing technical issues in the shuttle program that you'd like to see NASA follow further and look at from a bigger and more integrated perspective?

ADM. GEHMAN: Did you say any more tactical issues?

A REPORTER: Technical.

ADM. GEHMAN: Technical issues. Oh. There have been a number of technical issues that the board was curious about that we directed that someone in the investigation take a look at. Every time we've brought one of these – I mean, the number of times this has happened, I could count on one hand, I think. Every time we've brought it up, they've instituted an inquiry into it. So nothing comes to mind. There are none outstanding right now. I don't think there are any outstanding.

You can't see here, but I'm looking at my colleagues up and down the row here. I can't think of any technical review – I know there are a lot of technical issues in which the work is not finished. Dr. Osheroff, Dr. Widnall, Dr. Hallock, Mr. Hubbard, Mr. Tetrault all have ongoing technical reviews and technical analysis in which more work has got to be done, but I can't think of anything in which we wish that NASA – if we wished NASA were looking at something, NASA would be looking at something and it wouldn't be a wish. So I don't think that I can answer that any better than that.

A REPORTER: Times Picayune. I have a question regarding the external tank dissection. I wonder if someone could provide more detail about how that testing of the external tank and the foam will proceed over the next month or so and what the presence of voids in ET 94 might bode for the production of tanks that is under way currently.

ADM. TURCOTTE: Well, two parts. The first part, we're going to continue obviously the dissection, I believe starting next week, of the minus Y bipod and –

ADM. GEHMAN: Better known as the left bipod.

ADM. TURCOTTE: Better known as the left side. Then after that, the plan is to put it all kind of together to make an assessment of how many voids there were and what were the possible implications of having that many voids and could it have perhaps caused the bipod to depart. That's really the direction.

Now, the next part, that NASA is currently looking at, is refining its procedure for encapsulating that bipod. There are several proposals that are under study right now to either encapsulate that – different design, different way of coating it. There are a number of proposals on the street and they're all pretty preliminary at this point, but that's going on as a parallel effort. But the main purpose of our dissection is to confirm that, in fact there were some voids and there was a problem and could it have been the precipitator of the bipod departing the ET.

A REPORTER: NASA Watch. A question for Admiral Gehman. A press release yesterday stated that you're going to be having a safety seminar for the 27th or 28th of April but the event is closed to the media and the public. Now, I've got to wonder why you put out a press release about something if nobody can go cover it. What's going to be discussed there? Why shouldn't the public see this? Isn't it kind of contradictory that NASA's safety process is being examined in intricate detail in public and yet yours is not going to be shown to the folks? I think this would be relevant.

ADM. GEHMAN: Well, we are going to cover much of the safety and risk-management and risk-assessment issues in public hearings; but on the other hand, I think for the good functioning of the board, for an open and deep and rich analysis of what we have to wrestle with here, the board needs to be able to deliberate privately, deliberate with just the board present. We need a mix of both, is the way I see it.

You're right, we want to be as open as we possibly can. We have attempted to do that by holding public hearings, by being available to the press; but we also need to balance that with some amount of time in which we deliberate matters amongst ourselves. It's a fine balance. I'm not sure that I'm going to get it 100 percent right, but I'm going to try to get it 95 percent right and we will report on this process.

I will say that a lot of what's going to go on in this safety seminar is educational and, you're right, there's no reason why the press couldn't be there. It's just that if a member of the board wants to demonstrate his ignorance by asking a question, I don't want him to be intimidated or in any way reluctant to say whatever he wants or ask anything that he wants, by fear that it's going to get reported someway. So we have to balance our requirement to do some things amongst ourselves and most of what we do in public. We've attempted very hard to strike that balance and I probably can't please everybody all the time, but that's about the best I can do.

MS. BROWN: Did I miss anybody on the phone bridge? Okay. That's the conclusion of the briefing for today. As usual, the board members will take a few questions afterwards. Thanks.

(End of conference, 2:03 p.m.)

Back to Event
Privacy Policy Disclaimer Accessibility