Columbia Accident Investigation Board Press Briefing
Tuesday, March 18, 2003

1:00 p.m.
Hilton Houston - Clear Lake
3000 NASA Road One
Houston, Texas

MS. BROWN: Thank you for coming. As usual, we've got a phone bridge today. So at the end of the briefing, we'll take some questions from the audience here, followed by some questions from the phone bridge. I'll turn it over to Chairman Hal Gehman.

ADM. GEHMAN: Thank you very much. We'll do the same thing we usually do. I have a few introductory comments. We'll let each of the panel members say what they and their fellow board members are doing. Then we will throw it up to questions.

I literally have almost nothing here to say, very few announcements to make. I'll be traveling to Washington, D.C., tomorrow afternoon, tomorrow evening; and on Thursday I'll appear before the Senate Commerce, Science and Transportation Committee hearing to give a progress report on how the investigation is going.

Next week we'll hold public hearings down at KSC on Tuesday and Wednesday and we'll be discussing things that are relevant to what they do down at KSC, which is shuttle refurbishment and launch and those kinds of things, but most importantly, of course, is the debris, the debris reconstruction.

The only other announcement that I have is that we have a number of interim recommendations that are beginning to percolate up through the staff, through the board. I'm not ready to announce any right now, but we've always mentioned that when we came to a conclusion on anything, that we would issue that when we were confident. And we have a couple of them that are bubbling up and they are at various stages of maturity. When they're ready, you can expect that we'll be issuing some interim findings and recommendations.

So with that, we'll go right down the row here and start off with Steve Wallace who, as you all probably know by now, is in the group that we label as operations and management things.

MR. WALLACE: Thank you, Admiral. My colleagues to my right are going to show more hardware and debris and chemistry sets today than I am. We're really more focused on areas of decision-making and communications, and that is very much the broad focus of the efforts that our group is involved in right now. As you know, Dr. Sally Ride joined the board and she's part of our group and is, as we speak, heavily involved in interviews on those subjects and is a wonderful addition, brings a good perspective on all those issues.

I want to talk a little bit about the decision-making issue. We've heard an awful lot about E-mails and particularly as regards requests for DOD imaging assets, on again, off again. I think an important thing to say about the E-mail trail is that's certainly not the story. That's maybe a fraction of it. So while we read and organize and storyboard and try to figure out the whole story of what happened specifically and what it says sort of culturally in terms of communication practices and relationships among different parts of the organization, we're heavily involved in witness interviews. We're doing typically several every day and will be for some time. I would also like to say we are trying to be fair about all this and not view this with perfect 20/20 hindsight. Obviously there are a lot of people who, in retrospect, may have wished they had done something differently, whether or not it might have affected the ultimate outcome.

We are trying to sort out in all these communications, E-mails, phone calls, whatever, what really constitutes normal banter, normal what-ifing versus something that's Ð keep that in context. We certainly don't want to do anything that might have a long-term effect of inhibiting healthy communication, healthy discussion among people with genuine technical issues and general technical discussions. General Hess, the other member of our group, and I, we'll be in Washington this week. We'll be interviewing some very senior NASA officials as well, which will give another level of the same discussion.

Our group is also looking at the flight readiness review, sort of certification of flight readiness, all of those processes that lead up to a launch. I'd like to say that everybody along the table here has a piece of the foam. General Deal literally has it today, but let me tell you what I will describe as our piece of the foam. It's the deposition of prior foam events in the flight readiness process. We have the well-known foam event in STS 112, the subsequent launching of STS 113 and STS 107. There were prior foam events. I think the best way to characterize this is we're going to do an audit of the whole history of foam events and particularly their disposition in terms of the subsequent flight readiness reviews.

Another area that our group is involved in, although it's somewhat of a shared responsibility, is return-to-flight issues. A lot of them are fairly obvious and have been discussed in the media and openly by NASA. I would say Ð and Admiral Gehman alluded to recommendations we will have Ð some of those will be in the nature of sort of return-to-flight issues and some of them will be longer term. I would say I don't expect us to be in any contest with NASA Ð in other words, they have some very good efforts underway at a couple of different levels. I've been invited and encouraged to follow along with them and sit in all the meetings I want. I've done that. So this board is not going to look to take any pride of invention or authorship in terms of the whole return-to-flight picture. I think we're all looking at the same goal.

Some of the things they are looking at Ð first I'd like to comment on launch dates. NASA has published some various launch dates, and I'm not sure they have always made it clear that the last set of launch dates they put out clearly were dates that were notional, if everything were done right today, the first time we could possibly launch would be such and such a date and the second of which is, by the way, we're going to readjust all those dates later on. I think it's quite safe to say those are for planning purposes. They don't expend a lot of overtime and resources unnecessarily. Those are just long-term planning dates.

Specific areas where they have actions underway. Obviously the bipod foam issue has been going on actually for some time, from 112. They have an extensive program that's well along. Other areas that they are looking at and we are looking at, of course, on-orbit and on-station repair capability. It's a very complex issue. And a broad scheme Ð this is both NASA has efforts under way and we'll be probably adding some further suggestions on imaging capability both on ground-based and space-based assets. And they're also looking at entry profiles, although again this is a troublesome issue. We keep asking all the experts, as we have these hearings, is there anything else you can do in the entry profile. I think the short version is that in any certified procedure there's just very little to be gained. I think they're looking to see even where there might be some possible incremental improvements.

So that's the update from our group.

ADM. GEHMAN: All right. General Deal.

GEN. DEAL: Thank you, sir. I'd like to thank you all for the opportunity to talk to you again. Our panel, again, is the one that's looking at material and maintenance and also various aspects of management. We're going from being simply wide to being pretty much deep and wide in the things that we're doing right now and following the foundation of no assumptions because our objective, as we all will state, is to examine everything objectively.

Kind of what our weekly report is and what we've been up to, we've been on the road in this last week. As a matter of fact, right now I'm the only group board member that's in town. General Barry, who was with you this morning for the hearing, has just taken off for D.C. Admiral Turcotte was at Kennedy Space Center last week; and he is currently up in Dallas, examining the reinforced carbon-carbon panel processing and processes up there. As for myself, I was in Colorado doing interviews last week. I was at Kennedy Space Center with Admiral Turcotte, after which I spent some time with the folks at Michoud in New Orleans.

We're cutting a pretty wide swath as we do what the Admiral calls our gumshoe work. I'm going to show a few examples of the spectrum of what we're doing shortly. We're auditing paper processes. You can image in processing the shuttle how many reams and reams and reams of paper there is, and we've got teams that are looking at each aspect of that.

We're examining and then also having various aspects demonstrate the non-destructive examination techniques that currently exist and that are used. We have some initial looks now going into the quality verification processes, which are still fundamental to shuttle operations. Toward that end, we've been conducting multiple interviews, over 30 interviews in the last week with technicians, with contract quality inspectors, with government inspectors, and also with management, looking at each person, several different processes of how they put their stamps on different processes.

In case you're not familiar, each technician and inspector carries a little miniature stamp around with them and when they have finished, rather than signing their whole name and all this other kind of stuff, they have a stamp with a number. We are looking at those processes. We've already talked to some of those inspectors, referenced their numbers, and by the paperwork that we're examining and auditing we're able to go back and see who we want to conduct future interviews with because that is a technician that has stamped this particular procedure on Columbia or on other shuttle processing.

You're going to continue to see more and more matrixing amongst the groups. Some of the things we're doing with Mr. Wallace or with Dr. Hallock. With Group 3's lead right now, we're monitoring some testing. Yesterday and today we're doing testing down at Michoud on the bipod ramp on one of the tanks. Last week and this week we're at Wright Patterson Air Force Base doing some things I'll show you on slides shortly.

So quality programs will remain a key area of examination for us. NASA inspections, as some of you have printed in your articles, are well down across the board. Most of those inspections have been shifted to a contractor, not unlike what the rest of industries have been doing. So the government mandatory inspection points, what was commonly referred to as GMIPs, are NASA's quality verification, kind of their last line of defense. Part of what we're doing is doing interviews and also examining the processes themselves to verify that those are on track and that we also have the right people with the right qualifications doing those things.

I'll give you an example of some of the quality verification that we have. The external tank, which you maybe know is 15 stories tall, has thousands upon thousands of inspection points and multiple methods of inspecting them. You can multiply that to the orbiter, which has many more parts, and the complexity of it.

Admiral Gehman has directed from Day 1 that we remain balanced. So we're not looking just for things that are off track or things that have gone wrong. We're also looking for some things going right. I'm going to show you some examples of that, and best business practices, if those exist, for us to look at, as well.

Then also, in addition to finding the cause, another key aspect of what we're doing is to eliminate what we believe is not a cause. I've mentioned this before. We have been looking with Mr. Wallace's group at the Spacehab and its payload. We've been looking at boosters. We are not ready to rule anything out yet, but we're getting pretty close to ruling some of those things out.

Now I want to start by ruling out a couple of things that some of you have printed about. Down at Michoud last week we had a test done, in part, because early on there was some talk about the GX6300, the adhesive for the ablative foam that was put on. Now, someone had accused the folks down at Michoud of having some old stock that they were using on the shuttle. Well, we found out that if you mix it properly and everything is done well, it's done like in a pharmacy. You walk into this area and if you're a technician, you're the patient bringing in a prescription and your prescription is your request for the adhesive. It's processed through one technician; another technician takes it and starts to mix up the components. They mix it up in the proper amounts, usually in a quantity of a pound. So we're not talking 50 pounds or a drumful of things; we're talking about a small area 'cause it's got such a short shelf life to it, 90 minutes. Then they take a sample of that and they go and put it in an oven and quick bake it so they can make sure it's got the right properties. Then they issue it to the technician who goes and does it.

Now, if a sample of this did happen to be sitting on a shelf and did get past that and someone tried to use it, you can see that they couldn't use it. It hardens up pretty well. Those of you on the telephone bridge won't be able to experience this, but any reporter that wants to come up afterwards and touch it, you're more than welcome to. So that kind of eliminated that, as long as the foam is mixed properly or the adhesive is mixed properly.

We went a step further. There's a Conothane that's the sealant in the primer that goes on the tank and has to cure for eight hours before foam is put on and also put inside of a patch if you have a damaged foam. We had them mix some of that up, and it's got a shelf life of 60 minutes. Then we went back a few hours later; and again, it's the same type of story. This is kind of like rubber versus being hard.

We also looked into how they test the foam whenever they're applying it to the tank. Every time they fly it, they go through viscosity checks. Then they also have about a 3-foot-by-3-foot aluminum test sample, which this is a portion of one, that they spray some of that foam on. Then they take that and they do various tests on that test sample that they had just sprayed on the tank, things such as pull tests to make sure it will withstand any type of pulling on the outside.

Then we had them, while we were down there, show us a foam repair. There's going to be an example here that you can come up and touch later on. We had them do a cross-section first. We put the Conothane in and we put the foam in there and do a cross-sectional cut for us. So we're looking at all those type of processes, as well.

I'd like to jump now into a few briefing slides for you. Again, I'm going to talk about the spectrum of things that we're looking at with the Admiral, looking at everything from bad to good to just, by the way, we need to evaluate these type of things. One of them Ð just a little bit of background information for some who may not be aware about the evolution of the bipod ramp design, which has been a big focus that Mr. Wallace discussed.

Next slide. For ETs 1 through 13, you had a pretty dramatic ramp. There was 45 degrees that came off. Back here you have the first few shuttle flights, a developmental flight instrumentation box that was also enclosed in foam. That went away after the first few flights. So pretty dramatic at the beginning and then they changed it.

Next slide. For Tanks 14 through 75, they greatly smoothed out that curve down to 30 degrees. So you can see the evolution starting.

Next. This is Tanks ET 76 through the present. It's going down inside of the foam that's on the tank. That's a picture of it actually on the external tank with a fully foamed area. Then this, for your information, was off of Flight 112. Mr. Wallace referred to the back corner that came off of the bipod ramp that went down and struck a component of the booster. So we're looking at how it has evolved and also looking at what NASA has been doing about it Ð two flights ago, as Mr. Wallace mentioned, we lost a piece of it Ð and how we've come and what we're doing. As some of you are already aware, NASA's already moving to remove the ablative material that goes under the bipod ramp which has been consistent on all the tanks.

Next. We're going to be looking at, okay, how do we evolve from that to that to that and what is the next design that they are already working on, as well.

Next. Radar signature testing. I mentioned it's happening right now at the Air Force research lab at Wright Patterson Air Force Base. We're doing testing for two purposes. One is for that mysterious object that we talked about that was seen from Day 2 to Day 4 on orbit of the orbiter, to try to see what type of radar characteristics we may be able to get out of this testing if we could perhaps determine what it was that separated from the shuttle and then reentered a few days later.

The other thing we are testing is various components of the shuttle to help the debris team try to predict what things were falling off and being shed from the shuttle from the California coast on inward. From the videos that we have, we're trying to see what type of characteristics they are, because we have radar signatures of a lot of this as it was falling to the ground. By testing at these various frequency ranges, we're hoping to be able to identify what some of the parts were.

Next. We've got 28 different materials being tested right now at the research lab, everywhere from different types of blankets to RCCs to various tiles to the Freestar which, as you know, is kind of a piggybacked payload that sits in the back of the payload bay, to different types of foam and external tank components and some seals, as well. Reports should come by the next time we do a press conference with you so that we can give you a little more details on that. Probably be released even earlier than that.

I also want to go back to reemphasize a couple of things about this mysterious object. To remind you, this was discovered after the accident versus while it was on orbit. This was not something being tracked while it was on orbit. This was a result of about six days later of what we like to call the most laborious examination in space command history. If you think about the orbiter as it's going around the globe, there are 3180 different observations of the shuttle. Now, this was more keeping track of the shuttle versus tracking the shuttle, 'cause that's not the mission; we're not tasked to do that in space command. We do track for it and we do de-conflict it with any known objects in space, but they weren't doing this fine-tooth examination while it was on orbit. So I just want to make that point that this was after the accident.

Next. This is just an example of some of the things we're looking at. Again, it's not that we think it has anything to do with the Spacehab, but we have to eliminate it. If you look at Spacehab, it's got the blankets that are all over it for protection. Every place where you see one of those little dark spots, that's just this little seal here that's connected to a ring button on the other side, kind of a protruding ball which snaps into the area. These are all pull-tested before the Spacehab orbiter flight. Could one come off? Possibly. Did it? Probably not. That's one of the things they're testing at Wright Patterson.

Next. As I said, the Admiral's got us trying to keep as balanced an approach as we possibly can in everything that we do. I want to give you an initial look. This is by no means a final look but some things that we think on the surface so far are going right.

Next slide. Particularly I want to show you something different. Again, this isn't necessarily related to where heat protruded inside the wing; but it's an overall thing that bears looking at. If you go down at Kennedy Space Center, for those of you who've been there, you can't turn around without seeing various posters that are there. USA's got these little things: "Safety Is An Attitude." They've got something that personalizes it a little bit. There's Astronaut Eileen Collins and her daughter and Don Thomas and his son, these posters that are around there to personalize it.

Again, you can't turn around without more visible reminders. Things that are being reflected through our interviews, as well. Again, these are the surface; and we're still prying beneath them. These are initial impressions.

Next. There are some active methods. If someone wants to speak out and say something is wrong if you've got a process going on, an in-process leader can halt an action at any single time it's going on. Lockheed Martin has a card down at Michoud. I've got one now that I'm carrying. It's that left card up there. It's how to conduct a huddle if you think something's going wrong. If you look at the very bottom of it, it says: "This is stupid." You throw the card down and you can stop the process. I call that the "This is stupid" card.

Then you go to USA and they've got a great card. People carry multiple cards like this time-out card. If anybody sees anything going wrong, they can throw it down. As a matter of fact, Admiral Turcotte saw that used by a junior technician as he was observing the Atlantis being de-mated last week down at the Cape. USA also has what they call the RATS program, which goes off to a huge matrix they have of risk assessments and score cards that drill down very deeply into their processes.

Next. When someone does speak out, there used to be a program that some of our interviews have given us down at the Cape called "Week at the Beach." You bring something out, and you got to spend a week at the beach for stopping the processing. It wasn't like you and I would want to spend a week at the beach; it was week unpaid at the beach for slowing down the processing. That mind set has disappeared, according to interviews we've had so far.

Examples of some of the things USA has touted. Some of their technicians had them eat lunch with a NASA administrator. This is a particular one from Michoud, won a $2500 award, was touted in both the Lockheed publication as well as NASA publications. NASA astronauts give something called a Silver Snoopy award. They give it out to technicians and NASA employees. There's a lot of awards that are available for cash and also recurring awards programs.

Next. Then you'd like to think that all of those would bring out the inputs that you want. If not, you can't hardly turn around without seeing these things that are projected up there. There's anonymous input forms that go directly to the NASA headquarters safety reporting system. So anyone in any level can send these things in anonymously, as well.

Next. So I've kind of given you a little bit of the spectrum of some of the things we're looking at, all the way from design through the testing through some of the different practices. I'd like to leave you with two quick points. One is that as a group and a board, as Mr. Wallace alluded to, we're examining how NASA defines what an acceptable risk is. For example, the foam losses in past missions, you've got to look at how and when and why and to what extent foam loss became acceptable.

The other thing we're looking at is you have to look at how the bulk of NASA is contracted out. You've got to examine, when do you that, not just the contractor performance but also the contract that they're performing to. You could have a lousy contractor and a great contract, or you could have a fabulous contractor but the contract that they're working to or the design that they're performing to is inadequate. By definition, you may not get the product that you need. So we're examining all those aspects; and we've brought in some contract experts to help us, as well.

Thank you for the opportunity to convey where we're headed. Much is happening. There's much to do. We'll look at, later, some of the things that we're doing. Thank you.

DR. HALLOCK: Good afternoon. It's my pleasure today to tell you what we've been doing on the engineering and technical analysis group. First of all, we have welcomed a new member on Friday. That is Professor Doug Osheroff, who's head of the physics department at Stanford University. He's joined us; and I'm looking forward to many, many interesting discussions.

In order to describe what the rest of us have been doing over the last week or so, let me do it in terms of starting at the ascent stage of a mission all the way to the ending which, in this case, is the debris stage. First of all, Scott Hubbard, as I think was mentioned, last week was at Southwest Research because we are getting ready to do the tests on foam again. Here we go, following the foam. We're all interested in foam. They'll be doing some tests starting in about two weeks, I believe, where they'll be taking larger projectiles, the stuff that was done a number of years ago in '99, I believe it was. Basically 1 inch by 1 inch by 1 inch and 1 inch by inch by 3 inches. Now we're trying to get much closer to the sizes that we're seeing in that film that I'm sure all of you have seen.

The second part has to do now with the external tank. During this past week they've been looking at External Tank No. 120, which I believe they're calling a cousin tank. It's a bit different except for the area that we're talking about, which is the bipod area, where what they did is to do some new nondestructive techniques in order to look at what's happening in this area, in the foam in this area, particularly the bipod area. So they did things like X-rays and laser shearography. Then what they're doing Ð in fact, they may be even doing it right now Ð is they're actually going to cut into this foam and actually cut it off and take a look at it, look behind it. Are there voids? Are there cracks? Are there other things happening in this area? Remember, I said that we're using this now in External Tank No. 120, which is a cousin. All of this is really to be a practice before actually going to the so-called sister tank which would be ET 94. So after they do the test that they're doing, as I say, in approximately an hour, tomorrow maybe, then the idea is to sit down and look at what happened and make sure that nothing was introduced by doing those tests that would hurt it. Then the decision will be made whether we will go and look at, as I say, the sister tank, the one that was used for the launch of Columbia. So that's with Scott.

I'm next in the group here, in that we're looking at a lot of things. Now, we've been hearing a lot obviously about foam and other things, but we're also looking at a lot of things which really haven't hit the headlines very much, because we still need to look at those kinds of things. So what I've been looking at are things like meteors. Could there have been a meteoroid hit or a space debris hit on what's going on.

The way we've been looking at that is the spacecraft itself has a number of very sensitive accelerometers on board. So what we're doing is, when they're not firing any of the reaction control jets, looking at the data to see if maybe sometime there was an event of some sort that occurred. We've looked at approximately half the data so far and sort of starting at the beginning of the mission and so far have not seen anything, but we really do need to look at it to see if it's true.

Another area Ð and this, by the way, shows that we are listening to people in that a lot of us have been getting E-mails and we've received a lot of things at the board now that we've advertised an E-mail address as well as a mailing address. People have pointed out there was a large coronal mass ejection. In my day we used to call those solar flares. Let me call it a solar flare. This occurred the day before the landing event, but the actual flare component didn't come to the earth until after the accident. However, there was a preceding shock wave which really contains the high-energy particles. So the question is: Could this have caused a problem? Because it turns out that shock wave came into the earth's environment just when the shuttle was beginning its deorbit burn. To do that, we got in contact with the NOA people in the space environment center. These people are in Boulder, Colorado, as well as people at Hanscom Air Force Base. Now, these are people who actually look at this data all the time because, as you probably know, if you do have one of these events, things could happen like all your cell phones will go dead, which maybe is a good thing. That is one of the consequences, and it has actually caused problems with power grids, too. So they actually look at this to tell people who have satellites to reorient the satellite or reorient the space shuttle or reorient something on the space station.

Basically what has come out of this thing, it was basically of no interest. It was very insignificant, but we still needed to look at it. Part of the reason it was insignificant is this coronal mass ejection occurred near the rim of the sun and so the earth really only received a glancing blow. As I said, there are a number of these things which we still need to be looking at and hopefully putting a check mark next to it, saying that I think we can dismiss that as being a participant within this event.

The next thing to look at Ð can I have that first slide? We've been talking a little bit and heard more and more about this thing called the photograph that was taken at Kirtland. In the upper left, this is probably the view that you have seen before; but as you can see, the people out in Santa Cruz have been work on it and using some very elegant techniques to try to clean up that image. That's what we're now seeing as this being the image. It's cleaned up quite a bit, and we probably can't do too much more about it. If you want to know the details of how to do it, let's do it afterward. It's very complex, but it's a very elegant technique.

So now the question is let's start looking in here. Now, is that something where maybe some RCCs are missing, leading edge type material? Is that what that's showing us? We also see what looks like maybe a protuberance. That's why, in talking to those of you who were here this morning, I was asking a question about seeing shock-shock interactions. That's probably what that may be, is a shock-shock interaction. Why is it there? Is it there because something is missing? That's a question mark. That's what we're looking at.

Very briefly, if you look down below here, that's looking at that now. You remember earlier that was interpreted as being maybe the tail or something like that of the orbiter. Now that they've cleaned it up, it looks like a plume here. Looking at it closer, it shows something that may be actually a piece of debris. We're not clear, not absolutely sure of that at this moment, but that's what that could be.

Moving on. Dr. Widnall has been spending time, once again, really dealing with the aerodynamic reactions and how aerodynamics and extreme heating interact. In connection with that, she's also been trying to look at what is the behavior of these things, dealing both on the exterior part of the shuttle itself but also what's going inside the wing, how do these things affect everything.

Now, my next thing to talk about is what Roger Tetrault's doing. Can I have the next viewgraph, please?

You heard a little bit of this. We have talked in the past about this particular piece. What we're talking about here, that is on the side of the door. This is supposed to represent the door. Here's a picture of the door. Here's where that piece is located. Basically the fuselage is over on this side. The door on the left wing Ð assume this is a door for a moment Ð opens this way. When it's open, it's close to the edge of the orbiter itself. So it opens this way.

Now, the interesting thing about that when we talked about it before was that we are seeing a spray pattern here, showing, once again, that there's hot gas. The superheated gas is escaping from inside the wheel well, going outward. Well, now we have another piece that's on the other side. And here it's shown and it's right up against the spar that the RCC and stuff gets attached to and it goes right up to the edge here. And what are we seeing here but the same thing. We're seeing the spray going now in the opposite direction. And this is the side that has the hinges on it. So what it actually had to be able to do is not only go out one side but it's now spraying out the other side where it has to fight against the hinges and get up to where the seals are within the door itself.

That's implying that we're talking about something that's got some pressure behind it and a lot of heat building up. How much heat? Well, you've seen this picture maybe. I can't see it very well from here but it's the uplock and the interesting thing about that Ð can I have the next viewgraph, please Ð still a little bit better Ð but the interesting thing about this is, look right down here. There's a corner missing. It has been melted off. This is titanium. In fact, to be specific, it's called 6-4 titanium Ð percent aluminum, 4 percent vanadium, and 90 percent of it is titanium. It melts at approximately ,000 degrees Fahrenheit. So now we have another thing that's inside this door, inside the wheel well area where the temperature, as we now know, thanks to this, is up around 3,000 degrees. So that's a large temperature.

We also can't say when all of this was happening, but at least having the superheated air coming out, this plume coming out on both sides of the door, so that obviously means the door is still on. When it eventually departed from the shuttle itself, we can't tell at this point; but sometime during the event we had very, very hot temperatures in here.

Now we want to look at what this material that's been plated on it. It's very directional. So we can tell from what direction all of this is happening. Depending on what that is, it could be very interesting. Again, it's aluminum. Well, we've seen aluminum being sprayed everywhere. That could also be chromium, for example, because there's chromium on the landing gear strut. I don't know what it is yet. Once we know what it is, we're going to start looking at it.

The question is: Do we really know this is from the left wheel well? Well, we have found the right door, the right landing gear door, and it has all four uplocks attached to it. So there's no question that this is from the left wheel well. Which one of the four uplocks is a question at this point which we would like to be able to narrow down.

But now see what we have. We have an interesting picture. We have a thing that we know was 3,000 degrees here. We have sprays of aluminum going around in different places and so on. So what we're hoping to be able to do is hone in on possibly where this breach actually occurred. That's very important. If we know where the breach originally occurred, now we can work backwards to start saying is that a panel, is it a carrier panel, or what is it, as being the place where everything came in.

So that's the story of our people. We've been pretty busy this past week, as you can see, but things are becoming quite exciting in the sense of having a lot of information telling us a lot of hints as to what's there. We're not yet ready to turn around and say here is the story, but we're getting many, many pieces of that puzzle. Thank you.

ADM. GEHMAN: Thank you very much.

MS. BROWN: Okay. We can take some questions. Go ahead.

ADM. GEHMAN: Orlando Sun, for General Deal. Could you elaborate on some of things you're looking at to make the determination of whether or not safety processes might have been eroded or changed as they were transferred gradually from government to industry; and have you seen any indications yet that that might be the case?

GEN. DEAL: Well, I've given you the initial impressions that we have; but I also want to stress those are initial impressions. The way that you get past the things that you see on walls is through the interview process which we've started. Down at Kennedy along the last week we did about 20 different interviews and so far they're substantiating what you see on walls, but we still have many, many more to do. That's where you're asking the people that have been working the shuttle systems for perhaps 20 years what changes have you seen, are they positive changes, what could be made better. A typical question we like to ask every single interviewee is a "King for the Day" or "Queen for the Day" kind of question: "If you were in charge, what would you do to make the processing better, the safety programs better, the quality programs better?" We're getting some good inputs from that and also getting some good reinforcement of the current programs compared to those things, like I mentioned earlier, the "Week on the Beach" program, which was not a positive program. So things are looking good now. However, we're at just the Phase 1 of that. We have many more interviews to do to see if that's consistent across the board from what everyone is saying.

A SPEAKER: USA Today, for Dr. Hallock. What kinds of things could give pressure to a jet of hot gas or hot metal coming out of the wheel well?

DR. HALLOCK: Pressure is a relative quantity. Here we're talking about, in order to be able to get this thing to actually be pushing against the door and making its way out, breaking through the seals and so on. It has to have some impetus behind it for that to happen. So the pressure that we're talking about here is not like the pressure in your tires or something like this. It's actually having enough quantity of this material inside the wheel well. Remember, we think it came in one way and there is a vent in front of it, but there's no other exit place in the wheel well itself. So the pressure is more because more and more of this material is collecting in that region and then obviously looking for a place to escape.

A SPEAKER: Is that material plasma or hot gas from the outside?

DR. HALLOCK: It's the hot gases. Maybe I should say a lot of people, particularly myself as a physicist, when people say plasma, we shudder a little bit. Plasma has a definition, and plasma means you have about 20 to 30 percent of dissociated atoms in the material. Here where we are talking about superheated air, we don't have that particular situation. So I try to talk all my compatriots into using that term rather than using the term "plasma."

A SPEAKER: Associated Press, for either General Deal or Dr. Hallock. The question was asked earlier and there wasn't really an answer from the panelists. The possibility of multiple breaches. Could someone address that? Is that being seriously considered by the board that perhaps there were multiple breaches letting in the hot gases from different places? And is there any more information on the launch debris, what exactly it may have consisted of and whether, indeed, there were just three pieces?

DR. HALLOCK: In terms of the multiple breaches, we haven't dismissed that. The issue is, once you get a breach of some sort and then all the other things that are happening there, it's possible that it would actually open up other breaches. Whether that's what's happened here, I don't know. Right now in order to try to work backwards, do the problem backwards, we're more or less assuming that it probably came from one place. When we find that that won't work, then we go to Plan B which says now let's say let's suppose in this area it could have come from this location and maybe in this area it could be another. Once damage started going, particularly late in the event here, a lot of areas are going to start opening up. So it's very likely at the very end, before everything broke up, that the whole wing could have been exposed. So it's one big breach at that particular time.

What was the other part?

A SPEAKER: Any more progress on what the launch debris was and how many pieces may, indeed, have come off?

DR. HALLOCK: I'm not aware of that.

A SPEAKER: General Deal, do you have anything?

GEN. DEAL: I think his group is working very closely with the NASA folks that are doing the photo analysis and video analysis.

ADM. GEHMAN: There's been no change to what we showed last time. We don't know any more, whether it was ice in the foam or whether it was one piece or two pieces or three pieces. There's been no change in that.

A SPEAKER: Washington Post. A question for Admiral Gehman. You had mentioned today, sir, that you were going to ask NASA to allow the board to have a say in what kind of tests are conducted, especially in terms of the wind tunnel tests and so forth, so that you're not just analyzing results after they've been conducted but actually saying what tests are being conducted. Can you talk about what's prompting this and how these requests are being received by NASA?

ADM. GEHMAN: I sure can. NASA has a lot of people working on this problem and they have their own investigation path which includes a couple of techniques like bounding problems, for example. They want to test something way at the right-hand edge of the problem and something way out on the left-hand side edge of the problem. We may have a different investigation approach and may be interested in a different piece of data or a different analysis or test in order to pursue our approach. So as we become aware Ð and we know just about everything that's NASA's doing Ð as we become aware, for example, that foam impact testing is just about to begin down at Southwest Research, we inject ourselves to make sure that, as long as they're writing a contract to do some testing, that they include our requirements at the same time. This is now going on across the board, and we are working this together. I couldn't be happier with the response. And it's a team effort and it's working great.

A SPEAKER: Dallas Morning News. You've said that there are no givens and that you hope not to beg any questions, but it almost seems as though return to flight is a given. Are you all examining the fundamental question of whether there should be a return to flight, and is there unanimity or consensus on that question?

MR. WALLACE: I would speak to return to flight at two different levels. I would say that I think in the days after the accident, the President stated the country's position on manned space flight, which is that it will continue.

As far as the board, we are looking at return to flight in two ways. One is the short-term, which I think we can define that as the return to flight necessary to ensure the continued viability of the International Space Station. That would be probably the shortest-term return-to-flight issue.

Beyond that, the board may and I think will reframe the debate, which has been held many times and will probably be held again, on who should go into space and why, what payloads require that people accompany them. I was thinking now as we feel like we're on the brink of war and how people are all worried about friends and relatives who are going off into a war zone, as I had the explanation of risks involved in various activities described to me by some experts, manned space flight is an order of magnitude or two more dangerous than operating aircraft in a hostile war zone. So I think that debate will go on again as to who needs to go into space and why, but I don't think we are going to answer that question.

A SPEAKER: CBS News. Two quick ones for Dr. Hallock. It's a geometry question. As I look at the leading edge or carrier panel between Panels 6 and 9 and think about a plume getting up against the spar of the wings, I'm assuming that the first data they see that's anomalous telemetry is because ambient air flow through the vent enters the wheel well causes that and then you burn through cables and perhaps burn through the wall of the wheel well at some point after that. Is that correct, or are you guys assuming that the plume enters the vent in the front of the wheel well? And just how that geometry sets up with where the best guess is right now that something might have happened.

DR. HALLOCK: We're actually looking at both ways. Obviously it's easier for it to come in through the vent, if it can; but this is a vent that has a lot of material in it. It's more like a screen as opposed to a vent itself. Once again, we're looking at the timing here, when did those sensors go off line, because that does say that we're in somewhere around here making contact with the cable and particularly the cable run that has all of those cables in it.

Now, we're going to have to move somewhere in order to be able to get to the point where we have these sensors just beginning to show a small amount of temperature change where, at the same time, we know eventually we're going to get a temperature in there on the order of 3,000 degrees to start melting this titanium. So right now we have many, many possibilities as to what it could be; and we can't narrow it down as yet to saying here's one or two ways for this to occur.

A SPEAKER: Just a related follow-up. Given the location of the tires themselves in the front part of wheel well, I don't understand how the tires get these kinds of temperatures and you didn't see something earlier. I guess I don't understand the temperature regime from the front of that wheel well back to the back, that you wouldn't either blow a tire or, if you had the plume coming in from the front of the well, that you couldn't get some pretty noticeable damage in the rubber. This jet of hot air will bounce around a bit; but you would see something, wouldn't you? I don't understand that.

DR. HALLOCK: Well, in fact, you said the right thing in there. When this plume entered, it can bounce around. You've got to remember this is a very rarefied atmosphere still. So we could be having 3,000 degrees at one end, which is melting titanium, and at the other end we'll have a sensor that doesn't know much is happening at the point. So you've got to have enough atoms in here to be able to convey the temperature itself. Temperature is a quantity that depends upon having something for it to register on.

You know, maybe you've seen in these reports where they say astronomers have found a place where the temperature is 10 million degrees and this is a place in space itself. Why? There's two or three molecules moving around with such energy that, yes, indeed, if you had a thing that those things could hit against, they would register a temperature that high. So don't think of it as being like heating up this room. It's very different because there's so few molecules there that you can get a great gradation right across the entire area. Yes, it's bouncing around. We know those kinds of things.

ADM. GEHMAN: And if you were in attendance this morning, Bill, you recollect that the reason we spent so much time on the chemical reactions involved here is because we're trying to achieve an understanding of how aluminum reacts, beyond where it melts and beyond where it burns. What we're leading to, of course, is a scenario in which a new path into the wheel well could be developed in seconds, I think. In other words, the normal process, the mapping process that you would have to have in your mind where heat enters here 10 feet forward and works its way back there may not be the process that took place at all. And we're trying to establish just how rapidly other kinds of processes can rearrange the inside of the wheel well and then match up with these temperatures. Right now we're still at the exploratory stage.

A SPEAKER: Houston Chronicle. My question is related to Dr. Hallock's. Again, it's this phenomenon you're seeing in the wheel well and I don't understand whether the escape is because the heat and pressure built up inside that compartment beyond its capacity to vent or whether a jet with a force behind it was actually bounced off of something or directly pressed against the door to cause this escape.

DR. HALLOCK: I think I can say I agree with you. I don't know either. That's part of the problem here, that it can be actually both issues here. Remember, we talked about before that we still have that pyrotechnic here, that release that is used to release landing gear. That hasn't gone off. That thing will go off at 500 degrees or something. So here's a place that the upper part of the wheel well, which if you get something over 500 degrees you're going to have this pyrotechnic go off, it obviously hasn't gone off and yet down at the door level we're finding temperature very warm, enough so that it is actually finding its way out of the wheel well itself. Very complex.

A SPEAKER: SpaceFlight.com. Mr. Wallace, you talked a little bit about the debris event on STS 112. I believe we were told originally there was some superficial damage to the solid rocket booster that got struck. I wonder if you had a chance to assess that and whether you could derive anything from that impact that might relate to a similar impact on the wing.

MR. WALLACE: Well, it damaged the skirt of the solid rocket booster. Foam material Ð and I'm not really the expert on this and I'll let my colleagues answer if they like Ð the bipod piece fell in a trajectory that's quite different from what we saw on STS 107 and struck the skirt of the solid rocket booster. Again, it was a foam-covered metallic surface, I believe, and it put a big ding in it. And I think part of the problem also was that when the solid rocket booster was recovered, there was also an issue, I believe, as to what might have been the extent of damage from the foam strike and from the water impact. So, again, our view on that is rather the way that event was categorized, you know. Was it called an in-flight anomaly? Actually it was called something of a lesser degree of seriousness, yet it went through a fairly thorough disposition process before the subsequent flights were launched.

GEN. DEAL: I'll just add exactly what Steve said. It's exactly the same, just different. I mean, it happened off the bipod ramp but it happened at 31 seconds or so as opposed to 50 seconds later, as our incident took place. One of the key things we're looking at is what happened subsequently. You know, this was back in October. There were two more shuttle flights. What types of decision went on for the flight readiness review of the two subsequent shuttle flights to assess that this was acceptable? So that's part of what we're looking at.

A SPEAKER: Aviation Week. I have a question that gets to the issue of the earliest events. Looking at the Rev 14 and Rev 13 master time lines at about 25 seconds after start of peak heating Ð and that's overall at 13:51:19 Ð we have remote sensors indicate off-nominal event, earliest known event. The question is: What was the event and what was the remote sensor? Was it a VSP missile warning satellite or another optical spacecraft sensor? What was the event and what was the sensor?

ADM. GEHMAN: I don't have my time line in front of me, but let me just say between Rev 13 and Rev 15 the first off-nominal event changed.

A SPEAKER: I see the gradient of issues there.

ADM. GEHMAN: Plus, they now have put an aero event. The elevon trim event, I think, has been moved up. But the first off-nominal temperature event was upper-left brake sensor temperature rise.

A SPEAKER: I think the operative words there to the question are "remote sensors indicate." So this is something is seen that is not telemetry; and the time there is 13:51:19.

ADM. GEHMAN: Okay. Then I'm not familiar with the entry then and I wrote Ð you're referring to what was a remote sensor?

A SPEAKER: Both. What would be the type of event that was registered on the remote sensor, and what was the remote sensor? That was well out over the Pacific.

MS. BROWN: We can get back to you on that.

DR. HALLOCK: I know where you're referring to. I know where it is on the time line and I even tracked out what sensor it was; but I do not remember, sitting here.

MS. BROWN: We can get back to you.

ADM. GEHMAN: We didn't bring our time line with us.

A SPEAKER: National Public Radio. I have a general question and a specific question. If you reflect back, please, over the last two days here, what have you learned? How has your thinking been refined by this exercise in understanding these rather complicated elements of physics and aerodynamics and so on? In particular, what do you make of the sensor readings that are around the vent lines, far away from Ð in front of the wing, which everyone is saying today, "I can't explain it by my theory, can't explain it by our calculations and analyses"?

DR. HALLOCK: One thing I've looked at, trying, once again, to do the answer analysis, work backwards, how would I get something in that area that would possibly raise the temperature. Whether this is what happened or not, I have zero idea at this point. However, suppose you do have a shock wave up closer in, much higher up in here, so where the wing is actually starting to come apart earlier. If you do get something like that, you can get a vortex that's here, as you heard Dr. Bertin talking about, which could then be coming up here and actually pulling off some of the blankets here and hence allow temperature to actually be sensed in that neighborhood as going up. Whether that's what's occurring or not Ð I mean, that's the only way I can rationalize it myself.

A SPEAKER: But the temperature goes back down again.

DR. HALLOCK: That's correct. Once again, you notice things are moving. As soon as you start moving the craft one way or another, whether it's a yaw or side slip, that's going to move the central point of where this thing would be impinging on here. You've got to ask the question. We see all these events from California on, lots of things are coming off. What can be coming off such that the people on board and the people on the ground, watching it, not know that? Well, there are things along here, things like the blankets here and the white tile on the top of here are such that you probably wouldn't notice that that's what's happening if those are the things that are actually coming off. So it's trying to say how do I explain it. Now, how do I get that to happen? I don't know. At least there's one way to try to explain what is the event, how do you get that event to take place.

A SPEAKER: Could I ask a more general question?

MS. BROWN: One each right now.

A SPEAKER: Well, I have a clarification, then. ABC News. I want to just clarify, Dr. Hallock. You are convinced that titanium uplock, that that damage was done while the shuttle was coming back, not after breakup, correct, because it was inside the well wheel and you know that the door was still on? Is that why you're convinced of that?

DR. HALLOCK: 99 percent convinced.

A SPEAKER: My question is that there was a published report that there's some particular interest in whether a carrier panel may have been missing, and there's some focus on that. Is that true and can you talk about why you're looking at that and whether it holds any more interest than anything else at this point?

DR. HALLOCK: You've got to remember where the carrier panel is. The RCC panels are the things here on the leading edge. The carrier panel is that panel that's right behind it that transitions from there to the tile. In fact, the carrier panel actually has tile on it. So the question is maybe it's not the RCC that actually came off for the initial entry of this but what came off would be that carrier panel. When you look at the film looking at the foam where it struck, it struck in this area and it struck in the area of the carrier panel. So eliminate that.

The next thing why I think it's important to look at it and we're waiting for what General Deal talked about is what was this thing that we saw on that Day 2 of the mission. That could conceivably be a carrier panel. That's about the size of what we're talking about, as well as what's called the horse shoe collar that's right behind it. If the carrier came out, that horse shoe collar may have become loose and come out. So there's two objects which seem to be about the size of what may have been detected on that second day. That's why we talk about it and having it as being a key thing. If the carrier panel came off, then it would be very easy to have damage occur such that the RCC panels themselves would come off. It's only held on, I believe, with two bolts. Get this thing out and get some heat in there in the right place on those Inconel bolts and it could come loose. And that's what could happen is all of this stuff is starting to open up into a larger area. We know it's got to be Ð as we saw from the Langley test, one thing, one RCC or one carrier panel is not really enough to really get all the temperature in. So we need more to happen, but that's one way to get this thing to start.

A SPEAKER: New York Times, for anybody on the panel. What is the state of your thinking about whether the shuttle should always be photographed on orbit and whether it should always carry or have the ability to do repairs in orbit, given that all remaining shuttles are now always flying to the space station? Hal is smiling.

ADM. GEHMAN: Well, I would say you're asking us for a conclusion that we're not ready to come to yet. I mean, all of those are relevant and pertinent questions and we'll address them, but I don't believe that we're quite ready to make a conclusion yet. Anybody else can chime in if they want.

GEN. DEAL: Sounded good, sir.

ADM. GEHMAN: I think that you're asking a question which is a bit more definitive than we are ready to make right now.

MS. BROWN: I'd like to take a few questions from the phone bridge.

A SPEAKER: Admiral Gehman. NBC News. I've been asked this question by several people during the past six weeks since the accident took place. As you mentioned a while ago, NASA's doing its own investigation; and, of course, you're doing yours. What if both of you come up with different answers? What happens?

ADM. GEHMAN: Well, there's only one investigation, and that's ours. All the NASA people work for us. It is entirely possible that in some minor detail or some technical detail we may come to a different conclusion than the NASA management comes to, because we're using the same data. We're all using the same data. We also may come to a different conclusion as to the significance of what this piece of data represents. That doesn't bother me in the least. I am not going to be influenced by their opinions, but they will be influenced by ours because our report will be the basis for the debate about how to fix these kinds of things.

As you are aware, our report does not go to the NASA administrator; it goes to the White House and to the Congress, as well as the NASA administrator. The implementation of our recommendations will be the subject of an intense public policy debate by the government. It might will be that, as Steve Wallace has indicated so clearly, we aren't going to be the adjudicators of return to flight but we will make recommendations as to the parameters of return to flight and those parameters might be too expensive.

MS. BROWN: Phone bridge.

A SPEAKER: Los Angeles Times. I'd like to ask a question about the foam versus micrometeoroids. If your research would ultimately indicate that a foam strike from the external tank could have damaged either the tiles or the leading edge, do you have a methodology for determining that it wasn't a micrometeoroid or, vice versa, if you determine that it could have been a micrometeoroid, how could you eliminate the possibility that it would not be a foam?

DR. HALLOCK: I don't think we're ever going to be able to say absolutely 100 percent this is what it was or zero percent this is what it was. We're going to be looking at what's the preponderance of the evidence. As I say, so far, looking for micrometeoroids, I'm not seeing any indication. If I don't see any indication, looking at all the rest of the data, in my mind I'm going to assign that a very low probability. Is it zero? I can't say it's zero; but I can certainly say it's very, very unlikely.

MR. WALLACE: I'd like to add to the answer. In terms of our final product, it happens in the civil aviation realm occasionally that the probable cause of an accident is not determined to a certainty; and the NTSB, in fact, sometimes couches their findings as more in terms of the most likely cause. So I think the ultimate objective of an accident investigation is to learn everything you can and go forward and make the system safer. So I think that even without an absolute certainty in an ultimate probable cause finding you may still have a very clear direction on improvements you can make and causes that you can eliminate, even if they are not established to a certainty.

GEN. DEAL: I'll underscore what Dr. Hallock said. We will never know 100 percent for sure that there were not micrometeoroids, but we have looked at previous shuttle flights where they mapped out all the tile damage and their have been micrometeoroid strikes. We also know that's there's national, international, university type resources that look at meteorites and we know about meteorites that fell during the orbits of the Columbia that weren't anywhere near. So we know it's not a major meteor. I'm not sure we'll ever be able to rule out a micrometeor, but we also know that previous shuttle flights have sustained them and come back perfectly fine.

A SPEAKER: Discovery Channel. My question is for Admiral Gehman. This follows along pretty much where you all have kind of headed in the last few questions. Do you intend, if you cannot determine with 100 percent certainty, which is very unlikely, given where the accident took place and all the variations and permeations that could have happened to various components on their way down, do you think that at the end, when all of this is said and done, that you will posit several scenarios, perhaps with a probability of each one occurring?

ADM. GEHMAN: Right now, based on the amount of evidence which is still flowing in, my confidence is still pretty high that we're going to be able to ascertain the root cause of this with some amount of certainty, not absolute certainty; but right now I'm not at the point where I have any view that we're going to end up guessing at this or even coming up with a number of possible scenarios. And that's based on the fact that evidence and information is still arriving daily and aircraft accidents with less data than this have been solved before. So the debris is still showing us things. We're still learning from the debris. We're still squeezing data out of the telemetry. So I'm not at that point yet.

MS. BROWN: Anyone else on the phone bridge who has a question? Okay. Then we'll drop out the phone bridge and take just two more questions here.

A SPEAKER: Newsday. I guess I'm still interested in Admiral Gehman mentioning this possibility of opening up a very rapid pathway to the wheel well. Does that necessarily require explosive burning of aluminum? There are some who are skeptical of that because you are essentially trying to get a fuel-air type of explosive with an even distribution of particles. In the chaos of what is going on in there, it seems that might be unlikely.

ADM. GEHMAN: You're right. What you see is us trying to characterize that environment; and the more we learn about how aluminum operates in these superheated temperatures, the better we'll be able to characterize that. But what is unfolding here is a scenario in which particularly a superheated air plume, a superheated plume of extraordinary high temperatures, above 3,000 degrees, could kind of carve its own way into the wheel well pretty rapidly. Now, we're going to have to characterize that a little bit better. Then also the fact that above certain temperatures, the aluminum actually becomes a fuel. It ceases to be a barrier and actually becomes a fuel. So this presents a new avenue for heat to get in, and we haven't characterized it completely yet. I mean, you're absolutely right. In order for burning to occur, you have to have oxygen. There's not much oxygen up there; but if you have a stream of even rarefied oxygen that's traveling 15,000 miles per hour, you can get a lot of oxygen molecules in a few seconds. That's what we've got to characterize.

MS. BROWN: Last question over here.

A SPEAKER: NBC. Dr. Hallock, the issue of the object in orbit on Flight Day 2 possibly conceived as being a carrier panel. Can you imagine any scenarios in which pieces like a carrier panel or an RCC panel or something else was damaged during ascent but then remained on for the rest of ascent and somehow worked loose in 24 hours in orbit? Any idea how that might have happened?

DR. HALLOCK: That's also one of the many scenarios we're thinking about on the same thing. This was pointed out to me very clearly by the astronaut who has been working with us, Mike Bloomfield Ð that is, the first 8 1/2 minutes of going to orbit is a wild ride. You are shaking around with 3 Gs and everything. I'm surprised a lot of things don't come loose when you're having something like that. From there on, it's basically a very mild environment in terms of accelerations upon you. So there are other things you can worry about Ð as you say, things like carrier panels and closeout panels and a lot of other things that could possibly have become loose, whether it was initially caused by this jarring caused by the foam hitting or whether it's something else. So you have to keep an open mind there. There's some other pieces that are on other places here which may have been able to move about for a while and then suddenly, when you started getting in this heating environment, then led one thing to another to another, falling dominos type of thing, to a lot of other possible scenarios.

A SPEAKER: How would it come loose after 4 hours, though, with practically no forces in orbit?

DR. HALLOCK: Think of what you also have. You have a very interesting heating environment. You spend Ð I don't remember the exact time. Was it 90 minutes you're in the very cold of space, where it's minus 250 degrees, and the next 90 minutes you're in sunshine where it's plus 250 degrees, whatever the time is Ð 45 and 45. I knew 90 was in there somewhere. I could calculate it. So you're having extremes. The temperature extremes, plus and minus 250 degrees Fahrenheit, do things to materials like metals.

GEN. DEAL: Plus some maneuvering of the shuttle.

ADM. GEHMAN: It turns out that just before this thing was spotted, they had just done a state vector change. They had just done a yaw; and if you've got no gravity, even a small motion like that's enough to throw something off. Astronauts have told me that on Day 2 or Day 3 of a flight, they look out the window and see a washer floating by. I mean, things happen. I'm not so sure we're going to have to prove, you know, exactly how this happened.

MS. BROWN: Okay, everybody. Thank you very much. We'll see you next week down at Kennedy.

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