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Columbia Accident Investigation Board Press Briefing
Wednesday, March 26, 2003

1:00 p.m.
Radisson Hotel
8701 Astronaut Boulevard
Cape Canaveral, Florida

Reporting: Keith L. Vincent, CSR
Esquire Deposition Services
Houston, Texas

ADM. GEHMAN: Good afternoon. We're pleased to be holding our press conference down here at KSC for a change. As is our usual practice, the board members have a few introductory comments to make. We will then be available to answer questions. The way we view these press conferences is this is an opportunity to dialogue. We aren't here to make news. We don't save up our news for Tuesdays or Wednesdays or whatever day of the week it is – we try not to, anyway – but this is an opportunity for you to dig a little deeper and delve a little more into what's been going on.

I am joined today by three board members representing three subpanels that we've broken ourselves into – Admiral Steve Turcotte, Major General Ken Hess, and Dr. Steve Hubbard, each of whom will get an opportunity to speak.

By way of introduction, I think you are probably aware that, unlike as I advertised last week, my testimony before the Senate Commerce, Science and Transportation Committee was canceled due to world events. So I don't have anything to say about that.

As we have revealed this morning in our discussions about debris, the way I would characterize what I took away from that for you is that about two thirds of the high-probability debris field grids have been searched and they're estimating it will take about 30 days to finish the remaining part. On the other hand, the detailed chemical/metallurgical scientific analysis of the debris has really just started. We really are just at the front edge of that. So we've got a lot more to learn from there, and we're just at the front end of that.

With that, I'll get out of the way; and we'll just go right down the row here. First of all is Admiral Turcotte, who is representing the group that does the material and maintenance issues.

ADM. TURCOTTE: Good afternoon. I'd like to give you a brief update today on the status of our group, which includes Brigadier General Deal, Major General John Barry, and myself.

General Deal spent much of last week doing interviews at Michoud and looking at the process of foam. We've all heard the term "follow the foam." We're starting from way back, going back to when the tanks were put together, and doing a thorough analysis of what that tank looked like perhaps when it went flying.

A first step to that was to take a tank that was of similar nature, last week, dissect it and see if we could find any abnormalities were process-related putting this into flight. We did find some anomalies. We found a couple of small voids that were in the bipod area where the insulation is sprayed and a couple of small voids that could probably cause – and we're looking at that – either a cryopumping effect or a breakage of some sort. That's still under analysis, and we're going to look at several other tanks to see if we find the same anomaly.

General Barry spent much of his time – you've all heard on Day 2 of the shuttle that there's a radar signal that showed something drift away from the shuttle. We have, in the process to try and get a better idea of what that perhaps might have been, sent several samples of what-ifs to the Air Force laboratory at Wright Patterson Air Force Base to take a look at what kind of radar cross-section could that have been and try and marry that up. We have sent – and I'll talk about it here in a second – some carrier panels, some blankets, some tiles, other various items that could have, in any one of our theories on the left wing, separated from the aircraft. That analysis is ongoing, we've got some preliminary data back. It's pretty inconclusive at this point. More to follow on that as we engineer and develop that data.

Finally, I spent some time looking at the reinforced carbon-carbon material last week in Dallas at the plant, and I'd like to focus my energy over here to the left. If you could look, the first big piece you see here is Panel No. 16. It is a reinforced carbon-carbon panel. It's about a quarter of an inch thick. It has a silicon carbide coating that carries the heat, and in between it is 19 plies of impregnated fabric that actually carries the dynamic load. So when you refer to an RCC panel, that's what a real one looks like. That came off the Enterprise. It's not flown hardware, but it came off of the Enterprise.

At the end of it, if you could turn it slightly and point out the T seal when we talk about what the T seal looks like. The T seal is on the far right hand side closest to you. If you could turn around so that you can see where it actually splits and joins and point to that, to the actual panel. Those are what link each of the reinforced carbon-carbon panels together on the shuttle.

ADM. GEHMAN: You can see why it's called a T seal.

ADM. TURCOTTE: Absolutely. That's why it's called a T seal. Now, what you don't see there are some of the metal linkage in the hardware that you may or may not have seen this morning from the public hearing. Now, that hardware is made out of Inconel metal which, as we found out, comes apart at about 2450 degrees. A large part of the inside of those RCC panels was covered with that linkage hardware.

Another two panels there. The very short one, is a closeout panel. The bigger one is a closeout panel that's from the top of the wing, and the smaller one's from the bottom. Carrier panel. Closeout panel. A number of different terminologies. But this is the panel, if you can hold that up and show that in relation to the RCC, where it attaches to the leading edge of the wing. It's about like that. So that's what's right between the blunt part of the wing and the actual RCC.

We're also looking at the processes. As in the foam, was there perhaps a degradation in the material. We're looking to go back to find out how old these panels, how long they've been on the aircraft, have they been inspected, and what quality perhaps were they. Both in the foam and the RCC, non-destructive evaluation is an ongoing issue that we're looking at very heavily to ascertain the actual flight conditions that the shuttle was in at the time that it took off.

That concludes my remarks.

ADM. GEHMAN: Thank you very much.

Major General Ken Hess.

GEN. HESS: Good afternoon. Over the period of the time in the last week, Group 2, which is myself and Steve Wallace, as well as Dr. Sally Ride, have busied ourself doing many, many interviews, to include going to Washington, D.C., last week to do some senior NASA officials. Steve Wallace continues his work toward return-to-flight issues as well as kind of a new mission for him, and that's focusing the board's recommendation process just a bit. Dr. Sally Ride has keyed in on decision processes that were involved in the key operational parts of this mission, to include the much-reported DOD request for imagery as well as the disposition of other STS foam events as they affected the decision to fly STS 107.

I would encourage us all just to keep in context the E-mails and a lot of the information that's been said until we have a pretty complete story here that will be reported, because the E-mails are just a very small part of the overall picture that will be put together by the group and recommended to the overall board for some degree of decisions.

We're also busying ourselves now, starting last week, taking a look at the safety organization. Of course, the Rogers Commission indicted the safety organization within NASA as being silent; and, of course, we're going to take a look at the newly re-engineered safety organization and ask ourselves questions about responsibility and accountability to see what opinions we might form in that regard.

As Admiral Gehman has indicated, the debris collection effort that we all heard about this morning is coming into its probably final stages and we will be bringing a briefing to the board through the debris committee out there that recommends how we actually will close that out and will be working with NASA to determine the appropriate way and timing on that closure effort.

Probably within the next week or ten days, I expect that we will close out from our previous deliberations all aspects of crew training and performance as they relate to the mishap, as well as certification issues on the crew itself.

That concludes my remarks.

MR. HUBBARD: I'm here representing Group 3 this afternoon. That includes Jim Hallock, Doug Osheroff, Roger Tetrault, Sheila Widnall, and myself. We've continued to use all the data we can collect from the telemetry, from the debris field, from other examinations of downlinked information to bound the event in the orbiter, and we're on the verge now of beginning to oversee some tests which we hope will either confirm or exclude some of the conclusions that you've been aware of.

This afternoon I'd like to report on three different areas. First of all, I would like to give you an update on the so-called OEX box. This is the flight recorder-like device that was found; secondly, talk a little bit about the analysis of the visual data, where we're hoping to hone in even more on where this external tank debris hit the leading edge; and then finally talk about the tests of the foam impact that are being prepared and will commence here in about ten days.

So to start, let's examine the OEX recorder. The million-dollar question, of course, is what's on it. It arrived in overall good condition. It's got 1-inch tape with 28 tracks on it. If you look closely in the lower right-hand corner, you can see the very end of the tape there, which had a crumpled and wrinkled section about 10 to 15 inches long. Initial testing that was done just yesterday shows there is no data on this section. We believe this is actually a good outcome. It indicates, we hope, that the data recording is back in the earlier part of the reel where it is, relatively speaking, undamaged.

The timetable for this is that the box is here at the Kennedy Space Center. They will duplicate the good tape that's on that reel and send it back to Johnson Space Center by Friday. That will be processed over the weekend, and the data review will begin on Monday the 31st.

We've looked into what is believed to be on this tape. If it is a perfect world, we will have 721 measurement sensor outputs. This covers the wings, the fuselage, and the vertical tail surfaces. Of particular interest are going to be 182 pressure measurements; 53 temperature measurements; and 447 loads, dynamics, and stress measurements. Among these will include a series of measurements, if we get all the data back, on the left wing – strains, stresses and strains, temperatures and pressures.

Now, we have to note that this has been through a very severe environment. We don't know if the tape has been demagnetized. We don't know yet the quality of the data on there. What I'm describing to you is if it's a perfect outcome. We also have to note that the wires from this box to the sensors pass through the same wheel well area where other sensors went off line. So just wait and see over the next few days what we find. If all the data were there that I've described, of course, this would be a gold mine of information that could lead us to a much, much better understanding of what happened throughout the vehicle and particularly on the left wing. It's expected that if it was a normal mission, it would have about 30 minutes of data from ascent and, in a nominal mission, an hour of entry data. Of course, no on-orbit data.

Now I'd like to turn to the work that's been done with the visual analysis of the external tank impact. I think you all know that there are two cameras that took pictures, one video and one film, of the debris-shedding event that occurred at 82 seconds. What the various visual analysis teams have been able to do, they have taken this data and taken the view from one angle, the back side, the view from the other angle, the front side of the orbiter at this time and constructed now a three-dimensional trajectory path. I think if you look here, you can see that path in red. It looks like a pipe and it begins very, very near the bipod ramp area – lending further credence to the speculation that this was the origin of this event – and carrying down to the leading edge there. I'll describe a little bit further in the next slide where the trajectory analysis says that it hit.

Now, imagine that this piece came off and it's tumbling and spinning, coning, turning, and therefore it's creating a footprint, an impact footprint. This footprint is probably at least 2 feet in diameter, perhaps 3 or more. It depends on exactly how this sample or this piece of debris came down through the flow field that couples with the vehicle as it's traveling.

If you take that information, a plotting of each position frame by frame, and put a 2-foot-diameter impact ring around it, then you see something like this. Imagine this impact footprint now intersecting with the three-dimensional leading edge here. It's the same kind of curved surface that you see on the RCC panel over here. As you can see, the area of impact begins somewhere around Panel 5, goes through Panel 6, extends into Panel 7, then begins to cover the tile acreage on the bottom of the wing and, of course, moves very close to the main landing gear door.

This information, which is derived directly from the visual frames both in the film from one angle and the video from the other angle, leads us directly into testing whether or not this impact could have been the initiating event for the tragedy that followed. So let me go now to foam impact testing.

Oh, you can see here another picture of how this footprint would have traveled across the T seal and across the RCC Panel 6 and then moving into what Admiral Turcotte described earlier as the closeout panel area. This is what informs about where to go and test to see what damage this could have created.

These tests will be conducted in four areas – the main landing gear door tiles, the wing tiles, the carrier panel also known as the closeout panel that I showed you, and the reinforced carbon-carbon leading edge subsystem. Currently two sizes are being evaluated by the NASA team. Their test plan is one that will be brought forward to the group, first Group 3 of the board and then, if necessary, consideration by the entire board before the tests are initiated. They're looking at a 1- and a 2-pound mass traveling at about 500 miles per hour, 700 feet per second. One size would be 3 inches by 12 inches by 24 inches. That is the best current measurement from observing the debris that actually fell off the tank and hit the wing. The other is a size of about 6 inches by 14 inches by 24 inches, which is the size that was first evaluated during the mission. The angles will be close to simulate to the visual observations, on the order of 10 to 20 degrees, and the calibration tests will be conducted at Southwest Research Institute, using a gas-pressurized gun with an appropriate sized barrel.

Now, the size of this piece is being also determined by the size of the piece that fell off during STS 50. If this is the bipod ramp – so this is an exact model of the foam – you look at this black line. This black line indicates on STS 50 the size of the piece that fell off. It weighed about a pound, some 700-plus cubic inches. This is close to the calculated dimension from the visual observations. So a chunk like this may well have been what fell off and hit the leading edge.

Once all the analyses are concluded, a piece like this is what will be fired from this gun into the four kinds of samples that I described; and that's informed by the visual analysis done that says in this intersection you could have hit any one of these four types of materials – tiles on the under side, tiles near the main landing gear door, a closeout panel, and, of course, the reinforced carbon leading edge.

I'll conclude now just by showing you one of the tests that was done in the calibration test. Don't pay any attention to that white plume. It just happened to be a cold morning with warm air. So this is condensation. This shows the kind of calibrations that have been done thus far with pieces of foam with angles that are approximately those of the ones that were observed.

I'll just finish by saying that we will continue to be challenged to match the tests and the analysis with the observed events and that we will not be able to conclude that we know the initiating event that started this tragedy until our theories match the facts. That's all.

ADM. GEHMAN: Thank you very much, panel members. We're ready for questions.

A REPORTER: Florida Today. I would just like to know where you are with the other element of the imagery, the spectral analysis of the debris to try to determine whether or not the makeup is only foam.

MR. HUBBARD: Well, there's two questions embedded there. One is spectral analysis of any of the visual data. We don't hold out at this point a great deal of hope that this is going to yield anything. It would be just fortuitous happenstance because of the kind of data that we've got. There's groups within NASA that are looking at this; but, frankly, at this point we'd be very surprised if we learned anything.

The other part of the question is what could be in here if something like this, indeed, was the impacting element besides just the foam. For that I will refer to the statement by Admiral Turcotte that when they cut open the External Tank 120, they found voids. Those voids could be places where so-called cryopumping – this is just the action of the very cold surface – in fact, condensed nitrogen or air or water vapor. So when a piece this size came off, it possibly could have carried ice with it. We simply don't know that; but in the testing, what's going to be done is probably some smaller-scale tests with materials other than just foam, to see what the impact might be.

ADM. GEHMAN: Scott, if I could follow up on that – and if I don't state this correctly, you correct me because I don't want to say something wrong. One of the reasons why in the foam impact testing we vary the weight, we vary the density is to cover all the possibilities there might have been something in there, without even worrying what it is. Is that right?

MR. HUBBARD: The initial baseline on the testing is to try to mimic as closely as possible what was observed, and that's looking like 1 to 2 pounds. But by varying the velocity and varying the mass, we can, in fact, mimic or bound, if you will, the possibility that there were other things in here. The question on the testing and how far we go is limited by the number of pieces of material we have to impact, to shoot at.

A REPORTER: New York Times. Why are you testing this against RCC that has not flown, when you've already shown us thermographs of RCC that has flown that presumably doesn't look like virgin RCC that has not flown? Will your tests be valid?

MR. HUBBARD: Well, your supposition is incorrect, Matt. The tests will be in a staged fashion, and one of the things that the board will insist on is that we get tests impact articles that are as close as possible to what was on Columbia. It's necessary, for purposes of calibration, to start off with some material that is 20-plus years old from Enterprise, RCC Panels 16 and 17. They haven't flown, but they've got the age on them. They will be instrumented with all manner of sensors so that we can understand what the impact may have done. Then once that's known, we'll move on to Panel 6 from Orbiter 3 that does have, in fact, more than 20 flights on it. So the intent there is to be able to duplicate as closely as possible the type of material that was on Columbia.

A REPORTER: A quick clarification. Orbiter 3 – 103, Columbia?

MR. HUBBARD: No, 103 is Discovery. That's where the used panel is coming from.

A REPORTER: I guess for General Hess. We're all aware of the images from Hawaii and the Kirtland Air Force Base which was by the employees on their own time using the small telescope. Are there any other images taken either from the ground or from orbits from U.S. Government assets, of Columbia, that were obtained incidentally that are available for the board; and, if so, can we get access to those?

GEN. HESS: Actually there are no other images that we have. I mean, the images that we have, you have seen. There is quite a bit of work going on, as Dr. Hubbard has related, in trying to enhance the current images that we do have. In fact, Kodak has done some things to take individual frames and enhance them. For example, enhancing digitally. It takes one of those frames and turns it into a 50-meg file. And they're meeting continuously to try to get the most out of the pictures that we do have so that we can get more conclusory information from them.

A REPORTER: Washington Post. On your continuing concept of a chain of events and working back from the RCC, have you found any contributing factors in the way the RCC is applied – the bolts, the hardware, weak spots that may have been aggravated, may have been lurking beneath the surface, because that RCC panel looks pretty sturdy on its own?

ADM. TURCOTTE: Yes, we have. Throughout the flight history of OV 102, it went through a lot. All but two of these panels were original. We've only replaced, on the left side, two panels – a number of T seals which I don't recall, but only two panels.

Now, in that, there's been maintenance, micrometeor impacts. They've gone back for some refurbishment. They've gone back through a couple of different layers of seals and sealing processes back at the factory, and at the OMMs they are inspected very carefully. At each of those, there were some areas of stress that were filled. There were some areas that were discovered; and as we have looked at the rest of the fleet, we are finding that in the rest of the fleet there are some areas of concern. There are some areas that have been repaired that we don't know enough about yet to make a judgment. That is part of the ongoing process of looking at ways to better understand what was really on OV 102 by looking at the rest of the fleet.

ADM. GEHMAN: By the way, there are other issues also. I mean, if Mr. Tetrault were here, he would answer the same question with a "yes" except instead of talking about RCC panels, he would talk about Inconel bolts and corrosion and exposure to salt air, as we were told by one of the astronauts the other day that, his calculation, Columbia had spent 2 1/2 years out on the launch pad. So there is corrosion. So there's a whole series of strength-and-materials issues here, of which the RCC panels is clearly one.

A REPORTER: NBC. Mr. Hubbard, could you show us on the RCC panel exactly where the footprint hit? Was that on the top leading side or back?

Also, Admiral Turcotte, would you share with us the preliminary data you received back from Wright Pat, what it points out at this time? We'll promise to be big children.

ADM. TURCOTTE: You want me to hold the RCC panel for you?

ADM. GEHMAN: It's sufficient to say it's the underside.

MR. HUBBARD: It's the underside. I was going to bring up the footprint diagram, but it's on the underside but it's an area that's so big, you know. It's sitting on the underside. That's correct.

ADM. GEHMAN: And the radar –

ADM. TURCOTTE: The Wright Pat? I will say that we have ruled out more than we have focused on, on a number of parts. And I can't remember the number. Somewhere between a number bigger than 15 and less than 20 went there, and we've ruled out a lot of the lesser things. Like blankets aren't very radar reactive. So we've got it down to a smaller group, but we don't have a clear enough definition on what that is. There's more tests to follow, different bands, different wave lengths we're going to look at to see if we can refine that even better. So the answer is we're narrowing down and we're excluding a few.

A REPORTER: Are the carrier panels still in there?


A REPORTER: I guess for Mr. Hubbard. Going back to the tests again. You mentioned the one piece falling off the bipod there. Are you going to also model that it broke into three, maybe three smaller pieces, or are you just going to throw that one big piece at it? When you shoot the one big piece at it, will the RCC panel be modeling this corrosion and both mechanical issues as well, or just the raw RCC panels?

MR. HUBBARD: Good series of questions here. If I forget it, remind me of it. First of all, the question about big pieces versus smaller pieces. The piece that I showed you here is one that was actually observed to fall off. At least from the dimensions, the mass, the weight and volume, it resembles what we believe fell off of here.

In 1999, there were a whole series of tests done with much smaller pieces, 3-inch-by-3-inch-by-1-inch pieces, at the same facility, Southwest Research, but in a different gun. One of the plans on the table is to duplicate some of these tests and carry them further, to shoot small pieces into other tiles or into some of these materials and to look at how those pieces might change as a function of temperature, you know, what happens if a foam is cold versus being room temperature and so forth. So there will be, I think, a growing data base of not only large piece but also smaller pieces, as well.

Now, at this point, I don't think the visual analysis is conclusive on whether or not there were three pieces that hit or only one. The frames simply don't show enough of that; and because of the impact energy, we're focusing naturally on the largest piece. But it's clear that we ought to understand what happens with smaller pieces and we're going to use that to fill out the test program.

Now, the second question that you had had to do with how do you simulate a real-life launch condition. And this is a difficult thing to do because this orbiter is rising at a velocity that puts a lot of pressure on the system, so-called dynamic pressure, maybe 700 pounds per square foot. Simulating this on the ground in something like that gun I showed you. It's difficult.

How we're approaching that is the following. First of all, there will be an actual unit like this that is hit by a piece of foam. It won't just be a sheet of carbon-carbon. It's the whole structure, and the structure itself is going to be instrumented by things called strain gauges that measure how much tension or compression, by accelerometers that measure how much vibration goes on, and by some other devices. Those will, in turn, be used to calculate from analytic models what would happen under the load of the launch and also to help us extrapolate to what happens when you take a piece of Inconel bolt, to use Roger Tetrault's favorite item, to fracture, how much stress does it take to fracture a bolt. So we're hoping that between the test approach and the analysis by all of this instrumentation, we will be able to give ourselves a good idea of what happened under launch loads.

Now, clearly if we see some things here that are very suggestive, it might be necessary to go back in with more tests, you know, perhaps find out whatever Groups 1 and 2 have learned about corrosion and maintenance, and factor that back into the equation; but we're very aware of the need to try to test the entire structure system, not just a piece of tile or a piece of carbon.

A REPORTER: WKMG out of Orlando. This question is for General Hess and Admiral Turcotte and it deals more with the war that is going on right now. How difficult is it for you guys to stay mentally, physically, emotionally involved in the game, as far as Shuttle Columbia is involved, when you see what's going on overseas in Iraq right now? And for Admiral Gehman also, are we still concentrating, is NASA and the White House and Congress still making this a priority when it comes to the accident, as opposed to the war that's going on right now?

GEN. HESS: Well, I can obviously speak for myself in that, first of all, personally and professionally, I'm very committed to the investigation that's ongoing. So I'm not necessarily distracted from my duties here, but I'm keeping an eye on the war very carefully and there's obviously part of me that would like to be with my comrades. But this is a very important work for the nation to get done, as well.

ADM. TURCOTTE: I concur with that. It's like we've lost some wingmen in combat; and that's the way we're looking at this, is going back in and trying to figure out the reason why. And we are just as focused. But like General Hess, I'm watching very closely the events overseas.

ADM. GEHMAN: For my part, clearly the events that are going on in Iraq have got everybody's concerns; and everybody's worried about it here on this board and in Washington. But there are still enormous things at stake as a result of this investigation. And there's a lot of attention. We have contact certainly weekly with the oversight committees, if not several times a week, and there are a lot of people paying attention to what we're doing here. So I don't feel any lack of oversight.

A REPORTER: ABC News. A couple of questions, I think, for Mr. Hubbard. First of all, in terms of the OEX recorder, is it possible that there was a strain gauge that might measure the velocity of the impact that hit the left wing that would be recorded on that box, the force or momentum of it? Second of all, in terms of the criticality of foam, do you have a sense of whether foam was a Criticality 1, for example, in looking at how it was treated?

MR. HUBBARD: Okay. First question. Could the OEX box have data in it from the ascent phase that measured the impact of this piece of foam? There are sensors on there that are strain gauge sensors, the compression transducers, pressure gauges. Whether or not you could pick out the impact of a piece of foam, even traveling at 500 miles an hour, from the enormous pressures and stresses that are going on during ascent? This period is near what they call Max Q. That is to say it is near the period of maximum dynamic pressure on the vehicle, which is some 700 pounds per square foot. What we have with a 1-or-2-pound piece of foam here is something that would be equivalent to driving in your car at 60 miles an hour and being hit by a 70-pound sack of cement. You're clearly going to notice that in your 2,000-pound auto. Whether in a 220,000-pound orbiter – in fact, the whole system here is millions of pounds – I would say it's very difficult. Certainly you would be looking down in the noise of this data and seeing if you can pick out any blip or blibbet. And they'll look at that but at this point I would say the signal-to-noise ratio is going to be pretty small.

The second question: Is foam a Critical 1 material? I guess I would turn to one of my colleagues here and say: Does that show up in any of your reviews as being a Crit 1?

GEN. HESS: It has not. I'm not going to say that it's 100 percent certainty it's not there, but in our initial looks in the FEMA process to look and see if foam has been identified as an individual component, the initial answer we're getting is, no, it is not.

A REPORTER: Palm Beach Post. Forgive me if this question has been asked in previous weeks. In your review, have you looked at the discussion on the foam from the FRR for 113, I believe, and was the analysis that they did similar to or identical to the one that was done in flight on 107 or different or less? If you could get into those details.

GEN. HESS: I think that the STS mission we want to start with is 112, and we're tracking the disposition of the foam events from 112 through 113 to 107. And we know that in the FRR process for 107, foam was not addressed as an issue. We are digging up all the paperwork on the mission between 112, where we had a significant piece of foam loss, to 113, to see how it was dispositioned in that particular event and taken care of. That analysis is not complete; but before we're done, we're going to have tracked that all through.

A REPORTER: Discovery Channel. For Mr. Hubbard. Could you compare and contrast the data that you expect to get from the Southwest Research Institute tests with the engineering analysis that was done during the 107 flight which determined the foam impact was not a safety-of-flight issue, and also when the Southwest tests are scheduled to begin?

MR. HUBBARD: Okay. The analysis that was done during the STS 107 mission was just that: It was analysis. What they did was to say we believe the size of the material that fell off was so and so big. 6 inches by 14 by 24, I believe, was what they were thinking at the time. And they went to a model called Crater. Crater is what's called in the trade a semi-empirical model. Basically it's a spreadsheet into which a lot of data points have been entered from previous tests; and they said, okay, this is about where it falls, using this analytical model, this computer tool, and therefore through three iterations of analysis or presentations, they concluded that there would still be enough material in the tiles. This model focuses on tile damage; it does not have RCC damage in its data base. There is another much less sophisticated model that is sometimes used, but this was a focus on the tiles.

That is different, quite different from what we're going to do at Southwest. Southwest built up a data base with small pieces four years ago; and we're going to go and actually fire a full-size chunk, as best that can be determined of the right mass and right dimensions, against existing not only tiles but the so-called closeout panels, as well as this RCC structure. So we're going to collect actual test data, not just run computer models.

A REPORTER: When is the test going to start?

MR. HUBBARD: The schedule. The first test will be with the tiles, because that's the most straightforward way to begin, will be the week of April 6th. I can't tell you exactly which day but during that week.

A REPORTER: Associated Press for Admiral Turcotte. I'd like to find out a little bit more about the flaws that you found in the bipod ramp foam from the one tank. Do you have any idea what the process called that, whether it was defective foam, improper handling or application? How many voids did you see, and how old was this tank? And just some more details about the whole thing.

ADM. TURCOTTE: Well, first off, the amount of voids, if I recall clearly, were 3. Three small voids that were found when we carefully dissected that.

As far as the age of the tank –

(To Mr. Hubbard) Do you know when 120 was built, how old?

MR. HUBBARD: That's a cousin of 94, but it's a couple of years old.

ADM. TURCOTTE: Just guessing, it's a couple of years old. It's not as old as the ET that was on Columbia, but it's a couple of years old. But the same process was used. We're looking behind those, however. There are some process changes that have happened over the years in the application of the foam; and that's part of what our investigation is looking at is exactly who did it and what processes were changed or what was done differently, what propellants perhaps were used back then and what are being used now. Those are all part of the investigation. And I might add further that we're going to go to a sister tank and take a look at that once we dissect one more bipod element. And then we're going to come up with a better test plan and dissect this one a little differently just to make sure that we did the first two right.

A REPORTER: Aviation Week. For Admiral Turcotte and General Hess. Admiral Turcotte, on the RCC documentation for Columbia, did RCC Panels 6, 7, 8, the general area of interest, have any significant write-ups or maintenance that you've tied into?

For General Hess. In your management interviews, have you found any threads or trends, not necessarily conclusions but threads or trends that are provocative?

ADM. TURCOTTE: I'll cover the RCC first. First off, again, all but two panels were on the orbiter since it first started flying. So over the years, you're going to see some wear and tear from both micrometeor damage or micrometeorite damage and just wear and tear. So, yes, we've carefully looked at each of the panels. We've looked at the records. We have carefully reviewed the records page by page from its last flight, its flow, and have done a cursory review of the records for its last major maintenance period in OMM and found nothing of significance that would cause us anything, any reason to think that we have a problem.

However, I just want to let you know there is maintenance done on most all of these, and there has been done for quite some time. Now, we're looking very carefully at the evaluation methods used to continue this and keep these in service. That is primarily the focus of what we're at and so we can understand what was really underneath those panels.

GEN. HESS: In answer to your second question, in terms of the management interviews, I would say we have not found anything provocative; but I think that's fairly normal. In any hierarchical organization, you're going to find different perceptions and levels of information as you work yourself up and down the levels of that hierarchy. So some of the disposition that we've seen between E-mails and our interviews with management about those same E-mails involve just a matter of the perspective that's viewed and based on the decisions that were made, as opposed to anything that's out of order.

A REPORTER: CBS. Some OEX questions for Scott Hubbard. I'm assuming that the 721 possible things you're measured, is that from mapping STS 109 OEX output so that you know which sensors were active and which ones might have failed over the years, No. 1?

No. 2, you mentioned that some of the left wing sensory wiring is in the same bundle – or I'm assuming you were trying to tell us it's in the same bundle on the outboard side of the wheel well and on the forward edge so that you could lose some of that data but you would still have other data on the recorder that might prove useful.

The last part of my normal 15-minute question is the void in the RCC panels, that void that runs along the wing. I'm assuming there are sensors in the leading edge of the wing – or I guess there are – and we could, in theory, get some sense of how hot gas is moving through there from the very beginning of this. Is that not a possibility that could give you some indication of where this started?

MR. HUBBARD: Okay. You'll have to help me here. I may have missed something here. Okay. The 721 measurements is a total and I have breakdowns, but they're not ready to be distributed yet. I am sure that we, within the next day or two, will be able to give you a much more detailed release, through the regular channels, of what they are and where they're distributed. So the sense of your first question was where do all these go?

A REPORTER: No, the sense of my first question is the OEX system, some sensors that have failed over the years have not been replaced because it's not an active system anymore. It was my understanding that the guys were going back to look at STS 109 to map out which sensors were actually operational going into this mission, and I was trying to find out if that 721 was in reference to that.

MR. HUBBARD: The 721 is – the best information I have as of an hour ago is that this is by actual count of the beginning of the mission. In other words, this box – Columbia, of course, is different. The three newer orbiters have boxes that are similar but not nearly as extensive. They may have 2 or 3 hundred sensors. This was part of the development of the first vehicle, but the 721 is the current sensor count and this is routinely read out after every flight. So when it goes up, they have a tabulation of which sensors are intended to be record; and, of course, that's checked against the post-flight data. So that was the first question.

And the second question was what, Bill? I forgot.

A REPORTER: I'm sorry. With the cable runs from the left wing or at least some of the left wing sensors around the wheel well and you could, in theory, lose some of those but you would still be getting data from the rest of the vehicle that would be of use to you.

MR. HUBBARD: Oh, yes. This box and the distribution of these sensors is all over the vehicle. I was just cautioning that if people expect that, you know, whatever bad thing it was that happened to the other wire bundles in the left wing would or wouldn't happen here is that, if it did, we might lose the data at roughly the same point. But there is data distributed throughout the vehicle, up on the fuselage, on the right wing and so forth. Some of that aerodynamic data could be extremely valuable in determining what the status of the vehicle was. And then finally you asked if the temperature sensors – and are there, according to the maps I've got, temperature sensors near the leading edge. This is the hottest area, and that's why the RCC is there to protect it. There are some that are near that; and if those recorded the data and stayed on line, we could hopefully begin a much better map of the temperature flow and maybe this plume of superheated gas.

A REPORTER: Florida Today. I am not sure for whom. A couple of weeks ago, y'all mentioned that you were closing out fault trees. I'm wondering if you've been able to exonerate any systems or elements such as the SRBs or the SSME shack; and I'm also wondering if you could give us an update on when we might see interim advisories, I think, as the admiral has called them.

ADM. GEHMAN: We don't do fault trees. That's a NASA methodology. NASA is currently briefing fault tree closeouts to their chain of command, which will eventually get to us for approval. We have agreed with NASA on the process. They have a couple ready to be closed out, and they have to agree themselves they're finished. Then whichever group has cognizance over that area will listen to the brief, and then a shortened version of that brief will come to the board for closeout approval. The process of NASA briefing themselves is going on right now for the first couple. I don't want to get ahead of them and say this fault tree's almost ready and this fault tree will be next because it might get rejected to go back and look at something else.

What was the second part of your question? Oh, interim reports. We have already issued interim advisories that are not interim reports. We are going to issue interim advisories whenever we are satisfied, ourselves, that a certain area should be – that NASA should be advised that we've come to a tentative conclusion on something and it is most likely going to be not in our report. If we are satisfied that we studied this enough, we might as well tell NASA about it as soon as possible. We have a couple that are percolating their way up. We looked at them as a board collectively last week. The first two needed a little more polishing and a little more research. So the answer is, yes, we are going to issue interim advisories as the board satisfies itself that we know enough about the subject and it will be useful for NASA to know about it.

A REPORTER: NASA TV. This one will be for Scott Hubbard. Your analysis showing that the debris hits the leading edge of the wing suggests that NASA mission management simply called it wrong during the mission in terms of where the debris hit. Can you comment on that and can you comment on that with respect to the gap filler tile or carrier panel tiles or whatever you're calling those tiles? And is that an issue, the fact that if they missed the call, you know, should they have done their work better in terms of figuring out where it hit?

MR. HUBBARD: Well, I don't want to get ahead of the other teams that are looking into management decisions and what the various processes were or checks and balances for decision-making during the pressure of a mission; but what I can say is this, that to get to this point, of being able to say within an error bar of a foot or two where this hit, required weeks of data analysis. We're at the two-month point here. This data had to be washed and cleaned and in some cases digitized, studied, evaluated. New models had to be created in two dimensions and then made into three dimensions. Coordinates had to be translated. So there was a huge amount of work to get to this point to be able to say that this is really looking like where the pork chop impact region was here. So whether or not that level of analysis could have been done during the middle of a two-week mission, I am not prepared to speculate on. It has taken quite a bit of effort to get to this point, though.

A REPORTER: And just the other part of that, too, where the carrier panel, the tiles. I mean, do they behave differently than the other tiles on the belly?

MR. HUBBARD: Well, right here you can see I've highlighted two closeout panels, carrier panels. What these are are the black tiles that cover a lot of acreage on the bottom of the orbiter, but they have attach points into a metal structure. So maybe if you can hold that up again there, we can highlight what we're talking about. So you see those tiles on the front there? Those are the kinds of tiles that you find on the bottom of the orbiter, but they have some differences. One is they're scalloped out on the edge.

In fact, these things are attached on the top by four bolts and on the bottom by two bolts and they are, in fact, scalloped out of this side. So this side here has less material on it than the acreage that's here. And, of course, there's all the structure that goes on underneath. So, yes, the thermal protection part of this is a similar kind of ceramic; but the structure of it is something different.

So, for example, if this pork chop shaped or lamb chop shaped piece of region happened to hit that just right on the edge, you can imagine snapping that off. Whether or not that's what actually happened, that's part of what the test is going to do.

A REPORTER: New York Times. For Mr. Hubbard. Actually I have a question that I already asked you a couple of weeks ago or more. Aside from the foam that disintegrates after it hits the underside of the shuttle, there's also another piece from another view, from another rear view of the beach tracker, as they call it, where you see this piece of solid material that seems to either hit the shuttle and bounce off or I was wondering if it is actually coming off the shuttle. And it is not a piece that disintegrates. It looks like a solid piece that remains in one piece.

MR. HUBBARD: I'm not sure if that has been validated. You know, the focus is on the big piece that obviously did hit about in this region, because that's the one that would have done the most damage. Smaller pieces seem to be visible; and one of the reasons that this very high-resolution, digitized version of the film is being prepared is to, in fact, go and evaluate that next level of detail. As General Hess said, a study of that is in process. What kind of impact it could have had at this point is speculation; but as I said, that's one of the reasons that tests are being run with smaller impacters.

A REPORTER: Have you looked into the possibility that that actually could have been a piece of the shuttle coming off as a result of the impact with the foam?

MR. HUBBARD: I don't think that that scenario has received very much attention because, if I can back up here – well, it's not – I thought red was reverse. Okay. Never mind.

The impact footprint from all the available visual data shows this column that's 2 to 3 feet across that proceeds from the bipod ramp area up here and goes down and hits the wing. There is no other data at this point that suggests anything came off from elsewhere.

A REPORTER: Houston Chronicle. I have two for Admiral Turcotte. Are the RCC Panels 6, 7, and 8 among those that were original to Columbia?


A REPORTER: On the radar cross-section tests, I could not hear your earlier answer on this; but I just wondered if tile ice, carrier panel, and RCC are still in the running among candidates that the returns could indicate was what was coming off the shuttle.

ADM. TURCOTTE: Most anything that is a hard object like what you see there is still in the running. What we've really taken off are some of the blanket materials, some of the frizzy blankets, those kinds of things that are much smaller and did not have a big cross-section; but I will say it's preliminary. We haven't done a full analysis. There is more in different frequencies, different wave lengths to be looked at. So those could be brought back on the table.

A REPORTER: I think this question's for General Hess and perhaps Scott Hubbard, as well. Just to revisit the 112 foam-shedding incident. We haven't really received much information about what damage was done to the solid rocket booster. There was some documentation from NASA released in the last week that said there was a 4-inch-diameter-by-3-inch-deep impact site on the booster. I'm wondering if you know any more about that and whether you think it's strange that in the following Flight Readiness Review there was really no reference to an impact on the booster, it just dealt with the fact that foam shedded.

GEN. HESS: I think the information that we have is consistent with what you just suggested, that there was a strike on the solid rocket booster. I have not seen the actual picture of that particular strike other than just the post-mission reports of it.

I've forgotten the second half of your question now.

A REPORTER: It was whether you thought it was strange that, in the discussions that seemed to follow at the next mission's Flight Readiness Review, it seemed like there was little reference to the fact that a booster had been struck, it was just that foam had separated from the tank.

GEN. HESS: I don't necessarily want to agree with your characterization of thinking it strange right now, because that would mean I've decided already. We are going to take a look at how that foam event was dispositioned from 112 to 113 to 107. It's a little bit difficult to track it through the safety process. So by the time I get back to Houston, hopefully, we're going to have all that data lined up so I can actually track it and determine for myself was it declared to be an in-flight anomaly and, if so, how was it handled. If it was an in-flight anomaly and handled as some lesser safety event, how was that disposition and was it handled at a lower level? All their actions may have been appropriate, but I need to read it all myself in a consistent fashion before I can make a judgment on it.

ADM. GEHMAN: I want to comment on the 112 foam strike. I mean, you saw the skirt, didn't you?

ADM. TURCOTTE: I saw a little bit what he's talking about. Just from the technical aspect, it was soft on soft. It was a part of a cover that had some other rubber material on it. So it was not a metal or it was not a hard object that it hit. So that was essentially the results of that analysis. Now, where that fits into the rest, I couldn't tell you.

A REPORTER: Orlando Sentinel. For Scott Hubbard, I believe. I understand that, along with all the other debris you're analyzing in the hangar, that you're also looking, of course, at remains of the crew compartment, which I guess are kept segregated from the other pieces of debris. Could you talk a bit about how much of the crew compartment you've recovered so far, what it shows as far as damage is concerned, and where the pieces were recovered along the debris track and what sort of big-picture conclusions you can draw as far as the forces it was subjected to and when it came apart?

ADM. GEHMAN: I'm the crew compartment guy. You are correct: Anything having to do with the crew is being reconstructed in the hangar, but separately. Anything that we learn from the crew equipment, crew compartment is examined; and if it's relevant to the investigation, if it tells us anything about the cause in the investigation or characterizes how the orbiter came apart, we then carry it over the top of the curtain and put it out on the floor. If it doesn't support our investigation as to what caused this accident, then we don't take it across the curtain. As far as questions like how long did the crew compartment stay together and things like that, we're not commenting on.

A REPORTER: L.A. Times. Could you tell me whether, when the RCC panels were originally designed and manufactured, whether there was a specification that it had to withstand a certain burst, a so-called burst strength or some type of intrusion specification and then, secondly, can you tell me if you've made any determination of whether ageing, these microfractures, these worm holes and voids, how much that would have reduced that strength?

ADM. TURCOTTE: First question, on design specs. This was designed primarily to withstand orbital debris types of impacts, and there was a number of tests done at very high velocity low mass that showed different failure modes. And the majority of those failure modes were survivable. Part of our investigation, to my knowledge right now, there was not any testing done on ascent impacts of high mass and relatively medium velocity. That's part of what we're looking at right now, and that's why we're doing the testing that we're doing.

Part 2. The ageing. This is a carbon fiber substance. It's got a porosity value of about 20 percent. It is very strong; but as in any composite material, it does age. Over those years, they have done extensive maintenance on it; and, yes, we have found some areas that have been repaired and brought back to life. We have seen a lot of cracks. We have seen some oxidation. Based on the inspection that we've done and the process that we've done, we've taken some out of service and replaced them. So, yes, they have aged. To what extent is part of what we're looking at very closely now to come up with a baseline assessment of the density and the actual makeup or the nature of really what we're looking at across the fleet.

A REPORTER: Was there an actual specification?

ADM. TURCOTTE: There are design specs, yes. And I don't have them in front of me but I can tell you they are X amount of millimeters thick and if they fail that, then after that you replace them. Those kinds of specifications, yes.

MS. BROWN: We're going to take three questions from the phone bridge now.

A REPORTER: For Mr. Hubbard. Forgive me if you said this earlier. First of all, with respect to the OEX –

MS. BROWN: Can you say where you're from?

A REPORTER: Washington Times. With respect to the OEX, is it too early to know whether or not there is a magnetic signal on the tape?


A REPORTER: Secondly, what's potentially the most important information you can get from that? Then with respect to the foam testing, can you describe the equipment used to fire the foam itself; and do the tests take into account that the foam might have ice or something like that?

MR. HUBBARD: Okay. The first question was is it too early to know if we have a magnetic digital signal on the tape. Yes, it is too early. That's what we hope to find out within the next day or two when the tape is duplicated here at the Kennedy Space Center.

The second question is the most important information. We have focused a lot of our attention on the left wing and particularly the left wing leading edge. If the sensors that are there were active and working and got recorded, that information would be extremely valuable. As I said in answer to an earlier question, though, if for some reason those sensors dropped out, the orientation of the vehicle from some of the other sensors could also help us determine the attitude of the vehicle; and that might give us a better sense of what was going on.

The third question was about what's used to fire the foam. It is a nitrogen-pressurized gas gun, and I think the sense of your question was how are we going to make it as much like the real event as possible. We're taking every precaution to see that the size and the mass and the velocity and so forth are like what was observed, and we're using all the sensor data that we'll get from instrumenting these pieces and therefore using analysis to determine what would have happened to the whole structure. So we can't duplicate everything, but our intent is to do a lot of analysis from sensor data and extend our knowledge out to where we don't have test data.

A REPORTER: Daily Press. According to NASA Langley Public Affairs, the investigation board interviewed Langley engineer Bob Dougherty and one of his supervisors, Mike Stewart, yesterday. I was wondering, now that you've interviewed them, what, if anything, you have to say about the significance of their E-mails, the ones that were written before this disaster, and were they handled appropriately and, if you don't know, if you can't say now, when do you think you'll reach the point where you'll be able to give a conclusion of whether these E-mails were significant or not.

GEN. HESS: This is Ken Hess. I haven't heard the outcomes of those interviews yet. Those did take place at Langley yesterday and there is a task force that runs along this seam between Group 1 and 2 that are conducting a lot of the background interviews that have to do with those E-mails. And I have to plead a little ignorance on the outcome of those interviews yesterday.

A REPORTER: Richmond Times Dispatch. A follow-up on that, General. You had talked earlier about keeping the E-mail exchange in proper context. What is the task force and your team learning about that proper context and the safety management issues, and could you describe in more detail how you're going back to the Rogers Commission safety recommendations and how they are implemented today at NASA?

GEN. HESS: Let me see if I can answer those. First of all, it tied together a couple of different aspects of what we are learning as you take a complete look at NASA and their organization or structure. One is that, being a very hierarchical organization, there are certainly levels of information and decision processes that are made at varying levels. That becomes very, very evident to us in terms of how we view the overall process of making a decision like the COFR, because lots of information gets worked at low levels and then it's basically informed through their committee process, if you will, because there's no way that the top executives of NASA could handle the volume of information that's required to get a shuttle commitment to launch. So there a lot of checks and balances to a process that reports out key issues and the most important issues to the leadership.

So as you begin to look at the levels of information that are available at any particular level, as well as the relationships between the various groups, you begin to have an appreciation for how the E-mails could have been perceived or how dialog between one particular group may have been perceived. And if we stand back from it as not being part of it, well, we can draw any number of conclusions. So we have to be very careful that we understand all of those relationships when we come to our final commitments to how we think that the issue was handled, be it for DOD imagery or for a decision on how the crater analysis was applied and how it was reported up the chain to the leaderships in the FRR process.

Secondly, when we take a look at the safety organization, the part that we want to take a look at and have an appreciation for is the level of oversight versus insight as well as what that means to the management levels. I mean, there is safety in the workplace where you're worried about loss of workdays and stuff; and all the statistics are excellent here. We have no indication that the NASA USA contractor family is not conducting a very aggressive safety program; but when you work the levels up and you try to ask yourself is there a fair balance between management and then independent safety oversight as I think was envisioned in the Rogers Commission, then we have to judge that a little bit differently. And we're doing that through getting as much information as we can and interviewing everybody that's involved in that process so that we can form a board opinion on whether or not we think that process is effective.

MS. BROWN: Thank you very much. That will conclude the press briefing for today.

(Conference concluded at 2:16 p.m.)

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