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News Conference on Columbia Disaster

Aired February 03, 2003 - 17:00   ET

THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.


THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.


WOLF BLITZER, CNN ANCHOR: CNN Space Correspondent Miles O'Brien is joining us with all the latest developments from the Johnson Space Center in Houston. Miles, tell us what we learned today.
MILES O'BRIEN, CNN SPACE CORRESPONDENT: Well, Wolf, let's get right to it. We're going to learn something right now from the Shuttle Program Manager Ron Dittemore, just began his briefing. Let's listen in.

(AUDIO GAP)

RON DITTEMORE, SHUTTLE PROGRAM MANAGER: ... it takes all of our attention on a daily basis.

(AUDIO GAP)

DITTEMORE: ... reviewing our engineering analysis and planning for the future and what we need to do in both the coming days and coming weeks.

Identifying the items that are being recovered is time consuming. It's difficult but as we met with our people in the field today we understand that the process of collecting the debris and relocating it to our staging areas is really picking up steam and I think that's going to progress rapidly over the next couple of days.

As of yet, I still do not have any recovered items of any special significance; however, we have put in place a process whereby if we identify something that we believe to be significant we will red tag that particular piece of debris and immediately send our engineering and technical people to review it.

Literally hundreds of people are involved around the state and hundreds supporting in many different locations. I mention to you again the National Guard and the local law enforcement, state officials, FEMA, EPA, FBI, NASA officials, just a large cooperative effort that is working well to try to help us understand the cause of the loss of the Columbia and its precious crew.

Today I intend to give you additional updates in technical data. I know there's a lot of information or a lot of interest in the analysis that we perform during the mission on the debris impact to the wing and I will talk to you a little bit more about that today.

I also have some information that -- some additional information on the timeline as far as what happened and when and I'll update you on those events. But before I get into that, I would like to take some time and talk about the members of this team.

As I watched them to respond to the events that unfolded on Saturday morning, at all times it was a group of individuals certainly with sadness and disbelief in their eyes but never a hint of panic. These men and women performed flawlessly, recognizing that they had lost members of their family, as we treat the crew members in this community, they continued to stay at their post and do the jobs that we needed them to do. I'm extremely proud of the members of our team all across the country.

A wise person told me a long time ago that true character is revealed when you come face-to-face with reality and when you come face-to-face with adversity and certainly these last few days have been a real challenge on us personally but I couldn't be more proud of the team. Under difficult and adverse circumstances, they have performed in the highest manner and they continue to do so.

Tomorrow, as you know, we're going to pause and reflect upon the crew of Columbia, their lives, their contributions, their memory, and although we can not stop our investigation and the recovery effort, we will pause in this location to take the time to reflect upon their lives, their sacrifice. It's a day of remembering. It's a day of remembering our friends and for us it's a day of mourning.

Out of respect for the crew and their families, I will not do a press conference tomorrow. I will meet again with you the day following. If there is any significant events that occur, we will alert you to those events that will be done out of NASA headquarters. But for us, tomorrow is a day for our reflection and a day for us to pause from these activities for a small time.

Let me talk to you a little bit about the timeline and update you on some of the changes from yesterday. I'm going to run right down a timeline as I did yesterday and I'll try to identify the specific engineering information that has changed.

At 7:52 a.m. Central Standard Time, I believe I started yesterday at 7:53. I'm going to back up one minute. At 7:52 a.m., we have identified that three left main gear brake line temperatures showed an unusual temperature rise. This was the first event, the first occurrence of a significant thermal event in the wheel well on the left-hand side.

At 7:53, as we were passing over California, we've identified that a fourth left brake line strut actuator and uplock actuator temperature measurements rose significantly. Yesterday I reported 20 to 30 degrees increase in five minutes. Now, we believe it's more on the order of 30 to 40 degrees.

At 7:55, a fifth left main gear brake line temperature showed unusual temperature rise. At 7:57 as we were passing over Arizona and New Mexico the upper and lower left wing skin temperatures failed off scale low. At 7:59, as we were passing over West Texas, I mentioned yesterday that we had evidence of increasing drag on the left wing that the aero surfaces were reacting to that drag to maintain our attitude and trim.

We also now have identified that in addition to the aero surfaces that the yaw jets on the right-hand side, two of the four yaw jets were firing. They fired for one and a half seconds, again trying to help the aileron and the elevon surfaces counteract what we believe is the increasing drag.

And although I said yesterday that it was well within our capability to maintain attitude, it was well within the flight control system's capability to handle the excursion. As we have continued to pour over the data, it's not the absolute value of the attitude change that is interesting. What is becoming interesting to us now is the rate of change.

The aero surfaces were doing what they needed to do to counteract the drag on the left side of the vehicle. The right yaw jets had to kick in to help the aero surfaces and it appears that we were losing ground as far as the rate of attitude excursion. It was not long after that point that we lost all data and communication with the crew.

We are still looking and processing for -- we're still looking for additional information. I talked to you yesterday about 32 seconds. Retrieving that data is not as easy as we originally thought and so it may take us another day or so to extract that information and determine whether it's going to be useful to us.

We also hope to go out directly to the White Sands Terminal where the data comes down from the satellite directly into White Sands. It's then relayed from White Sands over to the Johnson Space Center. We're going to go directly to the White Sands equipment and see if we can extract additional data, and so that effort is continuing.

So, again, there is certainly an interest in the wheel well. I caution you about conclusions. A temperature increase of 30 to 40 degrees in five minutes within the wheel well does not indicate that we have something structurally going on. The outside temperature is above 2,000 degrees. Seeing an increase in the wheel well of 30 or 40 degrees seems to indicate that that's not the point of any large thermal excursion. That's reflecting something else.

Remember I told you yesterday we had an increase of temperature on the left side of the vehicle, on the mid fuselage. I believe I told you 60 degrees in five minutes but a change in temperature of 60 degrees again does not represent a structural problem.

So even though these things are interesting to us we're still trying to find what caused these temperatures to increase, and given the fact that the outside temperature on the wing leading edge is 2,000 degrees, these relatively small increases in temperature are telling us something. We're just trying to find out exactly what they're trying to tell us. Did we have some type of penetration in the wing that the left main landing gear and the left mid fuselage were just reflecting an overall increase in temperature but were not the exact point of the penetration? That's what we're trying to figure out.

So, you can't draw the conclusions that the left main gear of the wheel well, we had a breach there. If you had a breach there, it seems logical that the temperature would be higher than just 30 or 40 degrees from what we normally expect.

But again, we're early in this investigation and we're still pouring over the data and this is the fluid nature of the business, so be cautious about those conclusions. We are certainly trying to be cautious ourselves.

I'm going to talk to you a little bit now about the tile analysis. I know there are a lot of questions about that. I'll try to go through that in a fair amount of detail to help you understand what occurred.

The first thing I'm going to do is talk to you a little bit about the timeline, the events, when we did certain things, and when we finally concurred on it not being a problem.

Launch occurred on the 16th of January. The first film review occurred the following day on the 17th. The first engineering meetings occurred on the 20th. We reported to the debris assessment team on the 21st, which means the engineering teams were starting to do their work.

They were trying to understand exactly what this debris was and so they spent a day reflecting upon it, identifying the assumptions that they needed to utilize in their analysis and they reported to our Debris Assessment Team on the 21st.

They completed an engineering analysis on the 22nd, final engineering reviews on the 23rd and the 24th, reported to the Mission Management Team on the 24th and again on the 27th, both those times reporting to the Mission Management Team the conclusion was that the debris that impacted the vehicle did not represent a threat to the safety of the crew or the vehicle.

Now, I'm going to talk to you a little bit about the assumptions used in our analysis because I've heard a lot of discussion in the last day concerning those assumptions.

The size of the debris utilized in our assumptions was 20 inches by 16 inches by 6 inches, and the weight was 2.67 pounds. The size was determined in two ways. One, we looked at the film and we estimated to the best of our ability the size of the debris.

Secondly, we utilized the information that we gained on STS-112 where we had debris from the same area shed from the tank. The difference on 112 was that we had the film that the flight crew shot of the tank after the main engine cut off and after ET separation. And as the ET was separating away from the orbiter, the crew was able to take pictures of the tank and we clearly identified where the debris came from, and because of those photographs we were able to understand the size of the debris that departed from the tank.

We knew the size and the location and that's why we could tell you it was from that bipod region, and based upon those photographs we determined that the size of the debris, being somewhat conservative, was what I told you, 20 inches by 16 by 6, and the mass of that particular piece of debris, again determined based on the density of that size of debris.

As we performed the analysis, we looked at different incident angles. The debris is not going to hit the underside of the wing at a 90 degree angle. It's coming from the tank and the orbiter relationship, if I can use this model for a second, the tank debris is coming from here.

It's transporting down to the bottom of the vehicle at a slight incident angle and it's going to impact the wing and come off. It's not going to hit directly 90 degrees. So, as it comes into the wing, you have to calculate how much energy it has depending on the mass and the size, so that's very important to us. We looked at incident angles bearing from 10 degrees, 13, and 16 degrees, again trying to bound our analysis. We varied the weight of the debris, again trying to bound it.

We utilized a program, a tool that we have that we've used many, many times to predict the penetration of any coding or the penetration of any tile based upon this debris, and this -- we know from tests and we know from previous flight experience that this particular tool over predicts damage to the bottom of the vehicle, to the tile or to the wing leading edge.

We've used it in the past when we have shed debris. We've used its results, its predictions, and compared it to actual flight experience when the vehicle returned and we were able to measure the debris. So, we know that it over predicts. It also has some conservatism in the model itself. I won't go into those details. I haven't got those all captured for you yet but I wanted to give you that background.

As we completed the analysis, trying again to understand as we normally do the worst case, we looked at two primary -- well, we looked at more than two but the two worst cases were the loss of a single tile near the main landing gear door and we also looked at the loss of multiple tile, not that we lost the entire tile but we lost a portion of the tile in a larger area, and the area we looked at was 32 inches by approximately 7 inches, approximately 2 inches.

So, our model was predicting that we could have damage to the bottom of the wing near the left main gear door, and on other areas predominantly outboard from the main landing gear door to the tip of the wing depending on the incident angle and depending on the size or mass of the debris so it varies. For the loss of the single tile at the main landing gear door and for the other case where you had more acreage damaged, 32 by 7 by 2 inch area, in both those cases the analysis predicted that even though you might have structural damage, and what I mean by structural damage is localized heating where you may have some effect on the basic structure in that area.

Even though you might have localized structural damage, you would not have damage sufficient to cause a catastrophic event, nor impact the flying qualities of the vehicle.

Now today we are also going to release to you our daily Mission Evaluation Room reports. I believe we have 15 reports and you can read through those reports and it will reflect a lot about what I have just told you probably in less detail than what I just shared with you.

So, why don't we stop at that point and give you a chance to ask me some questions and, again, I'm sharing with you information, as much information as I have available and, again, ask for your indulgence as we change this information from day to day.

UNIDENTIFIED MALE: Let's start over here with Bill, please.

QUESTION: Bill Harwood (ph) with CBS News. Ron, I'm curious. I agree I was kind of looking at the wheel well, but from yesterday I was kind of baffled by that sensor up on the side of the fuselage and trying to figure out how you get heating effects above the wing, if something is going on in the wheel well, and a physicist told me that you don't conduct heat up the side of the fuselage fast enough to reflect what's going on here.

And, when you're talking about possible other penetration areas, I want to make sure I don't misinterpret what you're saying. You're saying, I guess, it's possible that you could have a penetration somewhere besides the main landing gear wheel well, get some heating going on in some of the structural boxes of the wing itself, and then perhaps have something happening in that nature but you're still talking about heat from below that would be somehow in the wing structure itself than manifests itself else.

DITTEMORE: That's exactly my thinking also. I'm speculating a little bit here because I have no data or evidence to really say that's what happened but I'm trying to think in my own mind how would the temperature increase in the wheel well and on the side of the fuselage and still end up with an event that lost a vehicle?

It does not seem logical that the wheel well is the source of the problem because the temperature does not reflect it. We have now five different temperature sensors all showing 40, 50 degree increase over five minutes, the side of the fuselage showing an increase.

There's some other event. There's some other missing link that we don't have yet that is contributing to this temperature increase and we've got to go find that.

UNIDENTIFIED MALE: Let's go right here to (UNINTELLIGIBLE).

QUESTION: (UNINTELLIGIBLE) with the "Palm Beach Post." Mr. Dittemore, I'm wondering is there any type of contingency entry scenario in which you would be able to, by say inducing a yaw during descent, protect one wing over the other, even if it's by a little bit? And also, did you see any increased skin temperatures on the left wing near the leading edge?

DITTEMORE: We have not seen any increase in skin temperatures that I am aware of. I'm reporting to you all the information I have. I mean you've got everything I know and if we do, I'll tell you as soon as I find out.

I'm not aware of any other scenarios, any other techniques that would have allowed me to favor one wing over the other, and obviously, you know, think about that for a second. If you favor one wing over the other, the wing that's not being favored is getting really hot, and so I'm sure that we didn't develop those scenarios.

But, I don't know for a fact that we couldn't have. I don't know for a fact that the analysis would have showed that it was not feasible. I can certainly ask some of our engineers and talk to you in the coming days but I'm doubtful that that's the case just from my knowledge of the thermal conditions.

You would also have had to make a judgment that you wanted to fly that way and sacrifice the vehicle because you can not meet your landing conditions by protecting one wing over the other. What you're really trying to say is can I enter through the atmosphere, preserve one wing because you think it might have some damage, and still make my landing conditions way down range?

That's not going to happen. You would have had to make the decision that you knew so much information about the damage on the wing that it was going to fail if you didn't protect it and then you would have had to make the decision that you were going to sacrifice the vehicle and get to a certain altitude and ask the crew to bail out. That's the scenario that you're asking me about.

And, I'm sure you understand that for us to have made that type of decision, we would have to have absolute sure knowledge and I don't believe that there is going to be any sensors or any pictures or any photographs or any video that would have got us there.

So, we can speculate all day long about what we could have done but I just don't believe that we would ever have had enough information to make those type of risk trades so be cautious about that line of thinking.

UNIDENTIFIED MALE: OK, let's go to Mike and then right here.

QUESTION: (UNINTELLIGIBLE) with the "Orlando Sentinel." Ron, as you continue the process of recovering and sifting through the debris, what are the two or three items that you are most anxious to find that you think are the most crucial to helping you unlock what happened? DITTEMORE: We are extremely interesting in any debris upstream of the primary impact area. We've all seen the debris map as it stretches from Fort Worth down through Lufkin and even into Louisiana. We are primarily interested, and certainly if we can find wing debris structure, tile, but if we find any tile or structure upstream of Fort Worth, New Mexico, Arizona, if that exists that is extremely important to us because that's going to be real key in the puzzle.

And so, we have received a large amount of information from the public on what they have seen and based upon those reports we are methodically following up on each one of those reports to try to understand whether they were fooled by a phenomena that is natural or whether they actually saw something that would be a concern to us as far as the health of the vehicle.

And then you have to think about this for a second. Just go through the scenario in your mind. Let's say we did shed a couple of tiles. You're at 220,000 feet or so, because now we're at California- Arizona. We're descending rapidly. We're going through mach 20, 19, 18, fairly quickly, and you shed a piece of tile or two that are six inches by six inches.

Where are they? That's a difficult problem but we have people seeing if we can solve that problem. You have to know the characteristics of the tile or a piece of material that you're looking for. It's traveling at a high speed and it's at high altitude, and we have tools that will help us predict where that type of debris may land, but it's like looking for a needle in a haystack.

But that is not going to keep us from trying to look for it and so we have a special team that's following up on each one of those reports. We're analyzing the potential of where the debris might have landed if there really is debris, and searching for any key parameter that might unlock the mystery to this tragedy.

UNIDENTIFIED MALE: OK, right here and then right here.

QUESTION: Mr. Dittemore, Jenny Blankenship (ph) with KI News out of Austin, Texas. Have you ever viewed the ascent telemetry data to see if anything hit the left elevon? And also, you had mentioned the dimensions and the possible weight of the debris that came off of the external fuel tank. Once again, do you have any way of measuring or of at least estimating the mass of that?

DITTEMORE: The mass is going to be the weight. It's going to be 2.67 pounds. That's going to be the striking energy. The mass or weight of that amount of pounds combined with the velocity as it impacts the wing is all going to be converted to energy. And you saw some of that, if you saw the video on the film that I know that you have. As it struck the wing, it basically disintegrated into a cloud of smaller particles.

So it went from a mass of 2.67 pounds into the wing, dissipated its energy into a cloud of dust, basically, and what we're trying to understand is because of that disoperation of energy, what impact did it have on the tile. And that's what our analysts tried to do during the flight by assuming one tile completely missing and damaged and then assuming another scenario where instead of removing the tile, you actually scooped out material representing several tiles and then we looked at the thermal properties to see if that would represent a safety concern.

And in both cases, they did not. In both cases what we believe the worst case to be was perhaps a local penetration, local structural damage, perhaps some local yielding of the structure because of the temperature. But not to the degree that it would violate the structural integrity of the wing or its structure, just in very local areas.

UNIDENTIFIED MALE: Right here and then right here.

CHARLES FELDMAN, CNN NATIONAL CORRESPONDENT: Charles Feldman with CNN. If we can explore just a bit this missing link that you're looking for and I recognize this is a fluid situation for you, but it seems as if what you're saying now is you're not really comfortable with the notion that there was an event that began in the wheel well itself or the door of the wheel well.

You don't seem comfortable with the notion that the debris that fell off the booster would have been of sufficient impact to have caused the catastrophic event that we saw on Saturday. Can you give us a sense of what are some of the operating theories that are being explored that you think are logical, that you feel comfortable with, that in your mind might help explain to your satisfaction what could have caused this kind of event?

DITTEMORE: Well, it's a mystery to us and we seem to have some conflicting information. But the information of the temperature increase in the wheel well, even though it's small, it's unusual. It's not normal. The mid fuselage is not normal. It seems to indicate that we have some type of thermal event going on. Where that thermal environment is coming from, we don't know.

It does not seem plausible to me and to our engineers right now that the genesis of the problem to be in the wheel well. That does not seem plausible to us just because the temperature should have reflected a greater rate of increase if you were getting the plasma into the wheel well.

So there must be something else. And we don't know what that something else is. And so that missing link is out there. And here we are 48 hours from the event. So we're still struggling with it. We've made significant progress from Saturday to today. And I think over time we're going to make more progress.

If we can get our hands on that piece of debris that really helps us indicate where the genesis of the problem is, that would be very important if we find a piece of tile. Each tile is individually coded. And if we find that tile and can decipher the code, we'll know exactly where it came from on the wing.

And that's the missing link that we're trying to find. Once we piece that together, then we can map it and then make it fit the scenario. We have pieces of information. But I think it's around the edges. And that missing link is out there and we just need to be persistent and go find it.

I'm confident that we'll get more information that will help us come up with a plausible scenario. But we may never know the exact root cause because we may never gather all the evidence to pinpoint it happened at this location for this cause. We may never know that. And so we're going have to use our best judgment as to root cause. But we're going to work our darndest to figure that out and fix it.

UNIDENTIFIED MALE: OK, we'll get Marcia (ph) and then Mark (ph).

QUESTION: Marcia Den (ph), Associated Press. Ron, all these meetings that were held between the 20 and the 27, do you have any idea of how many engineers were involved in all these various meetings? And during this time, and even after that, was there any concern expressed by even a single individual, any reservations to the conclusion that ultimately was made?

DITTEMORE: At the time, I'm not -- I was not aware of any reservations by any individual in our team. Certainly, if you extrapolate out our analysis, and look at the worst case and say, but what if we're wrong -- and that is not uncommon in our business.

In fact, we encourage that. If people are -- they're not satisfied with the results or the analysis, or there is something in their gut that tells them there's more work to be done, we encourage them to come forward and talk about it. And at the time, I was not aware of anybody that had those feelings at least to the point where they could -- they would want to come forward and identify that there's still something that they think remains undone.

We also have a system -- we have a reporting system, a safety reporting system, agency wide that any individual can identify a concern, a safety concern. They can identify their concerns, their thoughts. They can do it anonymously. It's inputted into the system and we immediately react to it. We received none of those types of alerts. So even though there -- I can't say for certainty, Marcia, that there weren't people out there that had some reservations.

In fact, I would think it unusual that we had 100 percent of 17,000 people that work in this program to have 100 percent consensus and no reservations. That doesn't happen on even the easiest problems. So I would suspect there were some that had some reservations, but I was not aware of that. And if they did have reservations, at least they weren't brought to my attention.

Now, I am aware here two days later that there have been some reservations expressed by certain individuals. And it goes back in time and so we're reviewing those reservations again as part of our database. They weren't part of our playbook at the time because they didn't surface. They didn't come forward. But now that the event happened and now that that this data has come forward concerning some reservations or even their belief of the worst case, what if situation, we're going to look at that. We're going to pay attention to it. UNIDENTIFIED MALE: OK. I have time for two more here. Mark (ph) and then right here.

QUESTION: Mark Rhode (ph) from "The Houston Chronicle." How did you deal with the possibility that this foam was actually more massive because it had ice in it or on it? How did you eliminate that possibility or did you consider it? And I'm just wondering, you know altogether, are you now taking this off your list of possible contributions to the accident?

DITTEMORE: I don't think I'm smart enough today, Mark, to talk to you about the ice contribution to the mass of the debris. I may have to work on that a day or two and ask me that question on Wednesday. I'll go off and learn some more about that relationship. I don't know that today.

But certainly this debris is one of our primary areas of emphasis. We are completely redoing the analysis from scratch. We want to know if we made any erroneous assumptions. We want to know if we weren't conservative enough. We want to know if we made any mistakes. And so we are redoing the complete analysis.

Secondarily, we have a team of engineers and managers and technicians that are working to understand the shedding of the debris itself from the external tank. And this is how we're approaching it. We're making the assumption from the start that the external tank was the root cause of the problem that lost Columbia. That's our starting point when we look at the tank. And based on that assumption, what is the fault tree that would substantiate that particular assumption?

And so we're attacking that and that's a fairly drastic assumption and it's sobering. But we have asked our ET, our External Tank Project Management and their personnel, and our contractor to make that assumption and see where that leads us. And so, even though that's a drastic assumption, I think that's what we need to do.

UNIDENTIFIED MALE: OK, right here.

QUESTION: Samantha Levine (ph), "U.S. News and World Report." Is there any expectation that all these pieces of debris that you're finding scattered over a large area are ever going to be pieced together as a way to possibly reconstruct what happened? And if so, where might that occur? Would that be at Barksdale or would that be in some other location?

DITTEMORE: Well, I'm hopeful that the areas that we are most interested in, we will find enough debris to reconstruct. I'm really hopeful that's the case because if that's not the case, then identifying the missing link is going to be much harder.

As far as the staging area, all that debris that we gather is going up to Barksdale Air Force Base and that's going to stay there for the immediate future. We are discussing where the final resting place of this debris will be. And I believe by the time I talk with you again on Wednesday, we'll have that nailed down and agreed to and I'll be able to let you know where we think the final resting place of all this debris will be.

UNIDENTIFIED MALE: OK, let's go to Florida for five questions from the Kennedy Space Center, please.

QUESTION: Ron, this is Craig Kavalt (ph) with "Aviation Week." Viewing it from the drag side of the equation, are you equating loss of specific tile acreage to the drag figures you're seeing? And relative to the overall Columbia tile picture, not the debris hit issue; did Columbia have any unusual tile pull data either at Palmdale or here at KSC after the HST flight?

DITTEMORE: That's a good question and because we have asked that same question and one of the teams that we have established of many teams is to go back and review the inspection work, the modification work and any tile work that was performed at the Palmdale facility in California. And so that's an action for us to go complete. That's just one of many teams.

We're looking at our commit-to-flight process. We're looking at our inspections. We're looking at flight control systems. We're looking at our aero and thermal environments, many others. And so that's just one of several that we are looking at. And then hopefully, as we work ourselves through this investigation, we'll be able to, in some cases, rule out certain areas because we'll have enough information that clearly points to the fact that it is not a problem, does not -- it does not represent a contributing factor.

And there might be other subsystems that are in a gray area that we don't have enough information to rule them out. And then there are clearly others, like I mentioned to Mark on the external tank and the tile systems that are more in the higher area of focus than some others. So at this stage with only 48 hours behind us, it's all open. We haven't ruled out anything. But, eventually, we're going to be able to rule some subsystems out as a root cause.

QUESTION: This is Chris Criedler (ph) from Florida today. A few years ago, the Southwest Research Institute did a report for NASA on the impact of foam on tiles and what that meant and NASA told us today that that report was impounded. And I wondered why it was and if we could actually see the results of that.

DITTEMORE: Well, I think generally we have impounded information that we believe would be helpful to our investigation. I don't -- I don't know for a fact whether that particular report is impounded or not. And if it is, I don't know the reason why that would be at this point.

Certainly, that type of information is going to be useful to us. We'll just have to work our way through this period of time. But I should share with you that we have more things impounded today than we really need to have impounded because we're overreacting at this point to make sure we don't lose any evidence or any piece of information that might be an important contribution for the future.

So we are being conservative. We are overreacting. And over time, you're going to see us back away from the current state of affairs. You're going to have to give us a little bit of latitude there and work with us. But we're going to share with you as much as we know.

I've got a special team. Their entire objective, 24 hours a day, is data and record handling. And there are many people, even in our engineering teams that want access to certain pieces of information that is embargoed. And we have a team that allows the release of information. That's their specific assignment and duty. So even in our own teams we're struggling with get something access to data and we're working through it, again, reacting to our overconservatism. But give us some time we'll get to the right level. You'll get the information.

QUESTION: Ron, this is Stephan McClure (ph) for "The New York Times." I have a question, which is a follow-up to Mark Rhodes' (ph) question earlier. The debris, I saw in the ice team film clip, it is not orange. It's actually -- it looks white. So I was wondering if -- how sure can we be that it's actually foam or is it maybe the other side of the foam with the ice on it?

DITTEMORE: Well, if you read the Mission Evaluation Report that we're releasing today, it also says that as it impacted the wing, there was a white cloud that formed. I don't know what to do with that yet. I don't know if that's a poor choice of words and a better choice of words should have been light rather than whit because we're dealing with something that we're trying to visualize from a long- range camera, and it had an impact. And it certainly was light colored. Whether it was white or whether it was very small particles with a sun reflection, I can't tell you today.

And I'm not sure that when we wrote the report that we really understood what we were talking about. And I'm not sure that it was white or light colored. And that's one thing we need to recognize as we go back and reanalyze, we're going to get to the bottom of that particular description.

Even when I read the report, 10 days ago, whenever that particular event -- approximately 10 days ago, even before the end of the mission, I read that particular report with white description and circled it and wrote "light" to ask the question, are you sure it was white or just a light and a reflection. So we're digging into that. I'm not sure that means anything today.

QUESTION: Ron, it's Jim Banky (ph) with Space.com. Some questions related to debris. First of all, in what you said earlier about modeling debris falling off, are you suggesting there may be debris, albeit single tiles west of Texas on the way down?

And have you heard anything on the field yet -- I know you said you didn't look at anything yet about the state of debris -- does -- are there any early reports that even suggest that what debris has fallen is in a condition that could be helpful? And finally, real quick, have you correlated that observers in California with the timeline like you mentioned the other day that you might have by today? DITTEMORE: Well, that -- the observation that was forwarded to us from California is important to us because this particular observer described -- as he was watching the Columbia pass overhead, he described what he believed was, in his mind, tile falling off the vehicle. Now whether it was tile or not, I don't know. But we're talking to him and trying to understand from his description what that could have been.

I don't know if there is any debris in California or Arizona and New Mexico. I do know that we found tile in Fort Worth. And so, the fact that we found a tile in the Fort Worth area, largely upstream of the debris field, maybe significant. I don't know yet.

Again, because the tile is light, its ability to travel downstream with the rest of the heavy material may have limited it to land into the Fort Worth/Dallas area rather than go all the way down into Lufkin and further. We're still looking at that.

I'm speculating a little bit if this observation on the West Coast was correct in his interpretation and if we judge it to be the case, if we truly were shedding some material as early as California, that's going to be significant to us. Again, I don't know that to be a fact and that's why we have a special team whose sole purpose is to investigate those reports and to interview the proper -- or interview the observers so that we can understand exactly what they're saying.

Now, we get reports from all over the country. So some of the reports are going to not be fruitful to us and others might be. So we're going through the process of eliminating those that aren't going to pay any dividend. And we're trying to isolate those that we think are more interesting and it's still too early for us to tell whether or not there's any findings in there that could be useful to us.

QUESTION: Phil Long (ph). Ron, could you share some more specifics about the meetings immediately following the day after the launch?

BLITZER: Ron Dittemore answering questions now for almost an hour. We're going continue to monitor this briefing and get some additional analysis.

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Aired February 3, 2003 - 17:00   ET
THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.
WOLF BLITZER, CNN ANCHOR: CNN Space Correspondent Miles O'Brien is joining us with all the latest developments from the Johnson Space Center in Houston. Miles, tell us what we learned today.
MILES O'BRIEN, CNN SPACE CORRESPONDENT: Well, Wolf, let's get right to it. We're going to learn something right now from the Shuttle Program Manager Ron Dittemore, just began his briefing. Let's listen in.

(AUDIO GAP)

RON DITTEMORE, SHUTTLE PROGRAM MANAGER: ... it takes all of our attention on a daily basis.

(AUDIO GAP)

DITTEMORE: ... reviewing our engineering analysis and planning for the future and what we need to do in both the coming days and coming weeks.

Identifying the items that are being recovered is time consuming. It's difficult but as we met with our people in the field today we understand that the process of collecting the debris and relocating it to our staging areas is really picking up steam and I think that's going to progress rapidly over the next couple of days.

As of yet, I still do not have any recovered items of any special significance; however, we have put in place a process whereby if we identify something that we believe to be significant we will red tag that particular piece of debris and immediately send our engineering and technical people to review it.

Literally hundreds of people are involved around the state and hundreds supporting in many different locations. I mention to you again the National Guard and the local law enforcement, state officials, FEMA, EPA, FBI, NASA officials, just a large cooperative effort that is working well to try to help us understand the cause of the loss of the Columbia and its precious crew.

Today I intend to give you additional updates in technical data. I know there's a lot of information or a lot of interest in the analysis that we perform during the mission on the debris impact to the wing and I will talk to you a little bit more about that today.

I also have some information that -- some additional information on the timeline as far as what happened and when and I'll update you on those events. But before I get into that, I would like to take some time and talk about the members of this team.

As I watched them to respond to the events that unfolded on Saturday morning, at all times it was a group of individuals certainly with sadness and disbelief in their eyes but never a hint of panic. These men and women performed flawlessly, recognizing that they had lost members of their family, as we treat the crew members in this community, they continued to stay at their post and do the jobs that we needed them to do. I'm extremely proud of the members of our team all across the country.

A wise person told me a long time ago that true character is revealed when you come face-to-face with reality and when you come face-to-face with adversity and certainly these last few days have been a real challenge on us personally but I couldn't be more proud of the team. Under difficult and adverse circumstances, they have performed in the highest manner and they continue to do so.

Tomorrow, as you know, we're going to pause and reflect upon the crew of Columbia, their lives, their contributions, their memory, and although we can not stop our investigation and the recovery effort, we will pause in this location to take the time to reflect upon their lives, their sacrifice. It's a day of remembering. It's a day of remembering our friends and for us it's a day of mourning.

Out of respect for the crew and their families, I will not do a press conference tomorrow. I will meet again with you the day following. If there is any significant events that occur, we will alert you to those events that will be done out of NASA headquarters. But for us, tomorrow is a day for our reflection and a day for us to pause from these activities for a small time.

Let me talk to you a little bit about the timeline and update you on some of the changes from yesterday. I'm going to run right down a timeline as I did yesterday and I'll try to identify the specific engineering information that has changed.

At 7:52 a.m. Central Standard Time, I believe I started yesterday at 7:53. I'm going to back up one minute. At 7:52 a.m., we have identified that three left main gear brake line temperatures showed an unusual temperature rise. This was the first event, the first occurrence of a significant thermal event in the wheel well on the left-hand side.

At 7:53, as we were passing over California, we've identified that a fourth left brake line strut actuator and uplock actuator temperature measurements rose significantly. Yesterday I reported 20 to 30 degrees increase in five minutes. Now, we believe it's more on the order of 30 to 40 degrees.

At 7:55, a fifth left main gear brake line temperature showed unusual temperature rise. At 7:57 as we were passing over Arizona and New Mexico the upper and lower left wing skin temperatures failed off scale low. At 7:59, as we were passing over West Texas, I mentioned yesterday that we had evidence of increasing drag on the left wing that the aero surfaces were reacting to that drag to maintain our attitude and trim.

We also now have identified that in addition to the aero surfaces that the yaw jets on the right-hand side, two of the four yaw jets were firing. They fired for one and a half seconds, again trying to help the aileron and the elevon surfaces counteract what we believe is the increasing drag.

And although I said yesterday that it was well within our capability to maintain attitude, it was well within the flight control system's capability to handle the excursion. As we have continued to pour over the data, it's not the absolute value of the attitude change that is interesting. What is becoming interesting to us now is the rate of change.

The aero surfaces were doing what they needed to do to counteract the drag on the left side of the vehicle. The right yaw jets had to kick in to help the aero surfaces and it appears that we were losing ground as far as the rate of attitude excursion. It was not long after that point that we lost all data and communication with the crew.

We are still looking and processing for -- we're still looking for additional information. I talked to you yesterday about 32 seconds. Retrieving that data is not as easy as we originally thought and so it may take us another day or so to extract that information and determine whether it's going to be useful to us.

We also hope to go out directly to the White Sands Terminal where the data comes down from the satellite directly into White Sands. It's then relayed from White Sands over to the Johnson Space Center. We're going to go directly to the White Sands equipment and see if we can extract additional data, and so that effort is continuing.

So, again, there is certainly an interest in the wheel well. I caution you about conclusions. A temperature increase of 30 to 40 degrees in five minutes within the wheel well does not indicate that we have something structurally going on. The outside temperature is above 2,000 degrees. Seeing an increase in the wheel well of 30 or 40 degrees seems to indicate that that's not the point of any large thermal excursion. That's reflecting something else.

Remember I told you yesterday we had an increase of temperature on the left side of the vehicle, on the mid fuselage. I believe I told you 60 degrees in five minutes but a change in temperature of 60 degrees again does not represent a structural problem.

So even though these things are interesting to us we're still trying to find what caused these temperatures to increase, and given the fact that the outside temperature on the wing leading edge is 2,000 degrees, these relatively small increases in temperature are telling us something. We're just trying to find out exactly what they're trying to tell us. Did we have some type of penetration in the wing that the left main landing gear and the left mid fuselage were just reflecting an overall increase in temperature but were not the exact point of the penetration? That's what we're trying to figure out.

So, you can't draw the conclusions that the left main gear of the wheel well, we had a breach there. If you had a breach there, it seems logical that the temperature would be higher than just 30 or 40 degrees from what we normally expect.

But again, we're early in this investigation and we're still pouring over the data and this is the fluid nature of the business, so be cautious about those conclusions. We are certainly trying to be cautious ourselves.

I'm going to talk to you a little bit now about the tile analysis. I know there are a lot of questions about that. I'll try to go through that in a fair amount of detail to help you understand what occurred.

The first thing I'm going to do is talk to you a little bit about the timeline, the events, when we did certain things, and when we finally concurred on it not being a problem.

Launch occurred on the 16th of January. The first film review occurred the following day on the 17th. The first engineering meetings occurred on the 20th. We reported to the debris assessment team on the 21st, which means the engineering teams were starting to do their work.

They were trying to understand exactly what this debris was and so they spent a day reflecting upon it, identifying the assumptions that they needed to utilize in their analysis and they reported to our Debris Assessment Team on the 21st.

They completed an engineering analysis on the 22nd, final engineering reviews on the 23rd and the 24th, reported to the Mission Management Team on the 24th and again on the 27th, both those times reporting to the Mission Management Team the conclusion was that the debris that impacted the vehicle did not represent a threat to the safety of the crew or the vehicle.

Now, I'm going to talk to you a little bit about the assumptions used in our analysis because I've heard a lot of discussion in the last day concerning those assumptions.

The size of the debris utilized in our assumptions was 20 inches by 16 inches by 6 inches, and the weight was 2.67 pounds. The size was determined in two ways. One, we looked at the film and we estimated to the best of our ability the size of the debris.

Secondly, we utilized the information that we gained on STS-112 where we had debris from the same area shed from the tank. The difference on 112 was that we had the film that the flight crew shot of the tank after the main engine cut off and after ET separation. And as the ET was separating away from the orbiter, the crew was able to take pictures of the tank and we clearly identified where the debris came from, and because of those photographs we were able to understand the size of the debris that departed from the tank.

We knew the size and the location and that's why we could tell you it was from that bipod region, and based upon those photographs we determined that the size of the debris, being somewhat conservative, was what I told you, 20 inches by 16 by 6, and the mass of that particular piece of debris, again determined based on the density of that size of debris.

As we performed the analysis, we looked at different incident angles. The debris is not going to hit the underside of the wing at a 90 degree angle. It's coming from the tank and the orbiter relationship, if I can use this model for a second, the tank debris is coming from here.

It's transporting down to the bottom of the vehicle at a slight incident angle and it's going to impact the wing and come off. It's not going to hit directly 90 degrees. So, as it comes into the wing, you have to calculate how much energy it has depending on the mass and the size, so that's very important to us. We looked at incident angles bearing from 10 degrees, 13, and 16 degrees, again trying to bound our analysis. We varied the weight of the debris, again trying to bound it.

We utilized a program, a tool that we have that we've used many, many times to predict the penetration of any coding or the penetration of any tile based upon this debris, and this -- we know from tests and we know from previous flight experience that this particular tool over predicts damage to the bottom of the vehicle, to the tile or to the wing leading edge.

We've used it in the past when we have shed debris. We've used its results, its predictions, and compared it to actual flight experience when the vehicle returned and we were able to measure the debris. So, we know that it over predicts. It also has some conservatism in the model itself. I won't go into those details. I haven't got those all captured for you yet but I wanted to give you that background.

As we completed the analysis, trying again to understand as we normally do the worst case, we looked at two primary -- well, we looked at more than two but the two worst cases were the loss of a single tile near the main landing gear door and we also looked at the loss of multiple tile, not that we lost the entire tile but we lost a portion of the tile in a larger area, and the area we looked at was 32 inches by approximately 7 inches, approximately 2 inches.

So, our model was predicting that we could have damage to the bottom of the wing near the left main gear door, and on other areas predominantly outboard from the main landing gear door to the tip of the wing depending on the incident angle and depending on the size or mass of the debris so it varies. For the loss of the single tile at the main landing gear door and for the other case where you had more acreage damaged, 32 by 7 by 2 inch area, in both those cases the analysis predicted that even though you might have structural damage, and what I mean by structural damage is localized heating where you may have some effect on the basic structure in that area.

Even though you might have localized structural damage, you would not have damage sufficient to cause a catastrophic event, nor impact the flying qualities of the vehicle.

Now today we are also going to release to you our daily Mission Evaluation Room reports. I believe we have 15 reports and you can read through those reports and it will reflect a lot about what I have just told you probably in less detail than what I just shared with you.

So, why don't we stop at that point and give you a chance to ask me some questions and, again, I'm sharing with you information, as much information as I have available and, again, ask for your indulgence as we change this information from day to day.

UNIDENTIFIED MALE: Let's start over here with Bill, please.

QUESTION: Bill Harwood (ph) with CBS News. Ron, I'm curious. I agree I was kind of looking at the wheel well, but from yesterday I was kind of baffled by that sensor up on the side of the fuselage and trying to figure out how you get heating effects above the wing, if something is going on in the wheel well, and a physicist told me that you don't conduct heat up the side of the fuselage fast enough to reflect what's going on here.

And, when you're talking about possible other penetration areas, I want to make sure I don't misinterpret what you're saying. You're saying, I guess, it's possible that you could have a penetration somewhere besides the main landing gear wheel well, get some heating going on in some of the structural boxes of the wing itself, and then perhaps have something happening in that nature but you're still talking about heat from below that would be somehow in the wing structure itself than manifests itself else.

DITTEMORE: That's exactly my thinking also. I'm speculating a little bit here because I have no data or evidence to really say that's what happened but I'm trying to think in my own mind how would the temperature increase in the wheel well and on the side of the fuselage and still end up with an event that lost a vehicle?

It does not seem logical that the wheel well is the source of the problem because the temperature does not reflect it. We have now five different temperature sensors all showing 40, 50 degree increase over five minutes, the side of the fuselage showing an increase.

There's some other event. There's some other missing link that we don't have yet that is contributing to this temperature increase and we've got to go find that.

UNIDENTIFIED MALE: Let's go right here to (UNINTELLIGIBLE).

QUESTION: (UNINTELLIGIBLE) with the "Palm Beach Post." Mr. Dittemore, I'm wondering is there any type of contingency entry scenario in which you would be able to, by say inducing a yaw during descent, protect one wing over the other, even if it's by a little bit? And also, did you see any increased skin temperatures on the left wing near the leading edge?

DITTEMORE: We have not seen any increase in skin temperatures that I am aware of. I'm reporting to you all the information I have. I mean you've got everything I know and if we do, I'll tell you as soon as I find out.

I'm not aware of any other scenarios, any other techniques that would have allowed me to favor one wing over the other, and obviously, you know, think about that for a second. If you favor one wing over the other, the wing that's not being favored is getting really hot, and so I'm sure that we didn't develop those scenarios.

But, I don't know for a fact that we couldn't have. I don't know for a fact that the analysis would have showed that it was not feasible. I can certainly ask some of our engineers and talk to you in the coming days but I'm doubtful that that's the case just from my knowledge of the thermal conditions.

You would also have had to make a judgment that you wanted to fly that way and sacrifice the vehicle because you can not meet your landing conditions by protecting one wing over the other. What you're really trying to say is can I enter through the atmosphere, preserve one wing because you think it might have some damage, and still make my landing conditions way down range?

That's not going to happen. You would have had to make the decision that you knew so much information about the damage on the wing that it was going to fail if you didn't protect it and then you would have had to make the decision that you were going to sacrifice the vehicle and get to a certain altitude and ask the crew to bail out. That's the scenario that you're asking me about.

And, I'm sure you understand that for us to have made that type of decision, we would have to have absolute sure knowledge and I don't believe that there is going to be any sensors or any pictures or any photographs or any video that would have got us there.

So, we can speculate all day long about what we could have done but I just don't believe that we would ever have had enough information to make those type of risk trades so be cautious about that line of thinking.

UNIDENTIFIED MALE: OK, let's go to Mike and then right here.

QUESTION: (UNINTELLIGIBLE) with the "Orlando Sentinel." Ron, as you continue the process of recovering and sifting through the debris, what are the two or three items that you are most anxious to find that you think are the most crucial to helping you unlock what happened? DITTEMORE: We are extremely interesting in any debris upstream of the primary impact area. We've all seen the debris map as it stretches from Fort Worth down through Lufkin and even into Louisiana. We are primarily interested, and certainly if we can find wing debris structure, tile, but if we find any tile or structure upstream of Fort Worth, New Mexico, Arizona, if that exists that is extremely important to us because that's going to be real key in the puzzle.

And so, we have received a large amount of information from the public on what they have seen and based upon those reports we are methodically following up on each one of those reports to try to understand whether they were fooled by a phenomena that is natural or whether they actually saw something that would be a concern to us as far as the health of the vehicle.

And then you have to think about this for a second. Just go through the scenario in your mind. Let's say we did shed a couple of tiles. You're at 220,000 feet or so, because now we're at California- Arizona. We're descending rapidly. We're going through mach 20, 19, 18, fairly quickly, and you shed a piece of tile or two that are six inches by six inches.

Where are they? That's a difficult problem but we have people seeing if we can solve that problem. You have to know the characteristics of the tile or a piece of material that you're looking for. It's traveling at a high speed and it's at high altitude, and we have tools that will help us predict where that type of debris may land, but it's like looking for a needle in a haystack.

But that is not going to keep us from trying to look for it and so we have a special team that's following up on each one of those reports. We're analyzing the potential of where the debris might have landed if there really is debris, and searching for any key parameter that might unlock the mystery to this tragedy.

UNIDENTIFIED MALE: OK, right here and then right here.

QUESTION: Mr. Dittemore, Jenny Blankenship (ph) with KI News out of Austin, Texas. Have you ever viewed the ascent telemetry data to see if anything hit the left elevon? And also, you had mentioned the dimensions and the possible weight of the debris that came off of the external fuel tank. Once again, do you have any way of measuring or of at least estimating the mass of that?

DITTEMORE: The mass is going to be the weight. It's going to be 2.67 pounds. That's going to be the striking energy. The mass or weight of that amount of pounds combined with the velocity as it impacts the wing is all going to be converted to energy. And you saw some of that, if you saw the video on the film that I know that you have. As it struck the wing, it basically disintegrated into a cloud of smaller particles.

So it went from a mass of 2.67 pounds into the wing, dissipated its energy into a cloud of dust, basically, and what we're trying to understand is because of that disoperation of energy, what impact did it have on the tile. And that's what our analysts tried to do during the flight by assuming one tile completely missing and damaged and then assuming another scenario where instead of removing the tile, you actually scooped out material representing several tiles and then we looked at the thermal properties to see if that would represent a safety concern.

And in both cases, they did not. In both cases what we believe the worst case to be was perhaps a local penetration, local structural damage, perhaps some local yielding of the structure because of the temperature. But not to the degree that it would violate the structural integrity of the wing or its structure, just in very local areas.

UNIDENTIFIED MALE: Right here and then right here.

CHARLES FELDMAN, CNN NATIONAL CORRESPONDENT: Charles Feldman with CNN. If we can explore just a bit this missing link that you're looking for and I recognize this is a fluid situation for you, but it seems as if what you're saying now is you're not really comfortable with the notion that there was an event that began in the wheel well itself or the door of the wheel well.

You don't seem comfortable with the notion that the debris that fell off the booster would have been of sufficient impact to have caused the catastrophic event that we saw on Saturday. Can you give us a sense of what are some of the operating theories that are being explored that you think are logical, that you feel comfortable with, that in your mind might help explain to your satisfaction what could have caused this kind of event?

DITTEMORE: Well, it's a mystery to us and we seem to have some conflicting information. But the information of the temperature increase in the wheel well, even though it's small, it's unusual. It's not normal. The mid fuselage is not normal. It seems to indicate that we have some type of thermal event going on. Where that thermal environment is coming from, we don't know.

It does not seem plausible to me and to our engineers right now that the genesis of the problem to be in the wheel well. That does not seem plausible to us just because the temperature should have reflected a greater rate of increase if you were getting the plasma into the wheel well.

So there must be something else. And we don't know what that something else is. And so that missing link is out there. And here we are 48 hours from the event. So we're still struggling with it. We've made significant progress from Saturday to today. And I think over time we're going to make more progress.

If we can get our hands on that piece of debris that really helps us indicate where the genesis of the problem is, that would be very important if we find a piece of tile. Each tile is individually coded. And if we find that tile and can decipher the code, we'll know exactly where it came from on the wing.

And that's the missing link that we're trying to find. Once we piece that together, then we can map it and then make it fit the scenario. We have pieces of information. But I think it's around the edges. And that missing link is out there and we just need to be persistent and go find it.

I'm confident that we'll get more information that will help us come up with a plausible scenario. But we may never know the exact root cause because we may never gather all the evidence to pinpoint it happened at this location for this cause. We may never know that. And so we're going have to use our best judgment as to root cause. But we're going to work our darndest to figure that out and fix it.

UNIDENTIFIED MALE: OK, we'll get Marcia (ph) and then Mark (ph).

QUESTION: Marcia Den (ph), Associated Press. Ron, all these meetings that were held between the 20 and the 27, do you have any idea of how many engineers were involved in all these various meetings? And during this time, and even after that, was there any concern expressed by even a single individual, any reservations to the conclusion that ultimately was made?

DITTEMORE: At the time, I'm not -- I was not aware of any reservations by any individual in our team. Certainly, if you extrapolate out our analysis, and look at the worst case and say, but what if we're wrong -- and that is not uncommon in our business.

In fact, we encourage that. If people are -- they're not satisfied with the results or the analysis, or there is something in their gut that tells them there's more work to be done, we encourage them to come forward and talk about it. And at the time, I was not aware of anybody that had those feelings at least to the point where they could -- they would want to come forward and identify that there's still something that they think remains undone.

We also have a system -- we have a reporting system, a safety reporting system, agency wide that any individual can identify a concern, a safety concern. They can identify their concerns, their thoughts. They can do it anonymously. It's inputted into the system and we immediately react to it. We received none of those types of alerts. So even though there -- I can't say for certainty, Marcia, that there weren't people out there that had some reservations.

In fact, I would think it unusual that we had 100 percent of 17,000 people that work in this program to have 100 percent consensus and no reservations. That doesn't happen on even the easiest problems. So I would suspect there were some that had some reservations, but I was not aware of that. And if they did have reservations, at least they weren't brought to my attention.

Now, I am aware here two days later that there have been some reservations expressed by certain individuals. And it goes back in time and so we're reviewing those reservations again as part of our database. They weren't part of our playbook at the time because they didn't surface. They didn't come forward. But now that the event happened and now that that this data has come forward concerning some reservations or even their belief of the worst case, what if situation, we're going to look at that. We're going to pay attention to it. UNIDENTIFIED MALE: OK. I have time for two more here. Mark (ph) and then right here.

QUESTION: Mark Rhode (ph) from "The Houston Chronicle." How did you deal with the possibility that this foam was actually more massive because it had ice in it or on it? How did you eliminate that possibility or did you consider it? And I'm just wondering, you know altogether, are you now taking this off your list of possible contributions to the accident?

DITTEMORE: I don't think I'm smart enough today, Mark, to talk to you about the ice contribution to the mass of the debris. I may have to work on that a day or two and ask me that question on Wednesday. I'll go off and learn some more about that relationship. I don't know that today.

But certainly this debris is one of our primary areas of emphasis. We are completely redoing the analysis from scratch. We want to know if we made any erroneous assumptions. We want to know if we weren't conservative enough. We want to know if we made any mistakes. And so we are redoing the complete analysis.

Secondarily, we have a team of engineers and managers and technicians that are working to understand the shedding of the debris itself from the external tank. And this is how we're approaching it. We're making the assumption from the start that the external tank was the root cause of the problem that lost Columbia. That's our starting point when we look at the tank. And based on that assumption, what is the fault tree that would substantiate that particular assumption?

And so we're attacking that and that's a fairly drastic assumption and it's sobering. But we have asked our ET, our External Tank Project Management and their personnel, and our contractor to make that assumption and see where that leads us. And so, even though that's a drastic assumption, I think that's what we need to do.

UNIDENTIFIED MALE: OK, right here.

QUESTION: Samantha Levine (ph), "U.S. News and World Report." Is there any expectation that all these pieces of debris that you're finding scattered over a large area are ever going to be pieced together as a way to possibly reconstruct what happened? And if so, where might that occur? Would that be at Barksdale or would that be in some other location?

DITTEMORE: Well, I'm hopeful that the areas that we are most interested in, we will find enough debris to reconstruct. I'm really hopeful that's the case because if that's not the case, then identifying the missing link is going to be much harder.

As far as the staging area, all that debris that we gather is going up to Barksdale Air Force Base and that's going to stay there for the immediate future. We are discussing where the final resting place of this debris will be. And I believe by the time I talk with you again on Wednesday, we'll have that nailed down and agreed to and I'll be able to let you know where we think the final resting place of all this debris will be.

UNIDENTIFIED MALE: OK, let's go to Florida for five questions from the Kennedy Space Center, please.

QUESTION: Ron, this is Craig Kavalt (ph) with "Aviation Week." Viewing it from the drag side of the equation, are you equating loss of specific tile acreage to the drag figures you're seeing? And relative to the overall Columbia tile picture, not the debris hit issue; did Columbia have any unusual tile pull data either at Palmdale or here at KSC after the HST flight?

DITTEMORE: That's a good question and because we have asked that same question and one of the teams that we have established of many teams is to go back and review the inspection work, the modification work and any tile work that was performed at the Palmdale facility in California. And so that's an action for us to go complete. That's just one of many teams.

We're looking at our commit-to-flight process. We're looking at our inspections. We're looking at flight control systems. We're looking at our aero and thermal environments, many others. And so that's just one of several that we are looking at. And then hopefully, as we work ourselves through this investigation, we'll be able to, in some cases, rule out certain areas because we'll have enough information that clearly points to the fact that it is not a problem, does not -- it does not represent a contributing factor.

And there might be other subsystems that are in a gray area that we don't have enough information to rule them out. And then there are clearly others, like I mentioned to Mark on the external tank and the tile systems that are more in the higher area of focus than some others. So at this stage with only 48 hours behind us, it's all open. We haven't ruled out anything. But, eventually, we're going to be able to rule some subsystems out as a root cause.

QUESTION: This is Chris Criedler (ph) from Florida today. A few years ago, the Southwest Research Institute did a report for NASA on the impact of foam on tiles and what that meant and NASA told us today that that report was impounded. And I wondered why it was and if we could actually see the results of that.

DITTEMORE: Well, I think generally we have impounded information that we believe would be helpful to our investigation. I don't -- I don't know for a fact whether that particular report is impounded or not. And if it is, I don't know the reason why that would be at this point.

Certainly, that type of information is going to be useful to us. We'll just have to work our way through this period of time. But I should share with you that we have more things impounded today than we really need to have impounded because we're overreacting at this point to make sure we don't lose any evidence or any piece of information that might be an important contribution for the future.

So we are being conservative. We are overreacting. And over time, you're going to see us back away from the current state of affairs. You're going to have to give us a little bit of latitude there and work with us. But we're going to share with you as much as we know.

I've got a special team. Their entire objective, 24 hours a day, is data and record handling. And there are many people, even in our engineering teams that want access to certain pieces of information that is embargoed. And we have a team that allows the release of information. That's their specific assignment and duty. So even in our own teams we're struggling with get something access to data and we're working through it, again, reacting to our overconservatism. But give us some time we'll get to the right level. You'll get the information.

QUESTION: Ron, this is Stephan McClure (ph) for "The New York Times." I have a question, which is a follow-up to Mark Rhodes' (ph) question earlier. The debris, I saw in the ice team film clip, it is not orange. It's actually -- it looks white. So I was wondering if -- how sure can we be that it's actually foam or is it maybe the other side of the foam with the ice on it?

DITTEMORE: Well, if you read the Mission Evaluation Report that we're releasing today, it also says that as it impacted the wing, there was a white cloud that formed. I don't know what to do with that yet. I don't know if that's a poor choice of words and a better choice of words should have been light rather than whit because we're dealing with something that we're trying to visualize from a long- range camera, and it had an impact. And it certainly was light colored. Whether it was white or whether it was very small particles with a sun reflection, I can't tell you today.

And I'm not sure that when we wrote the report that we really understood what we were talking about. And I'm not sure that it was white or light colored. And that's one thing we need to recognize as we go back and reanalyze, we're going to get to the bottom of that particular description.

Even when I read the report, 10 days ago, whenever that particular event -- approximately 10 days ago, even before the end of the mission, I read that particular report with white description and circled it and wrote "light" to ask the question, are you sure it was white or just a light and a reflection. So we're digging into that. I'm not sure that means anything today.

QUESTION: Ron, it's Jim Banky (ph) with Space.com. Some questions related to debris. First of all, in what you said earlier about modeling debris falling off, are you suggesting there may be debris, albeit single tiles west of Texas on the way down?

And have you heard anything on the field yet -- I know you said you didn't look at anything yet about the state of debris -- does -- are there any early reports that even suggest that what debris has fallen is in a condition that could be helpful? And finally, real quick, have you correlated that observers in California with the timeline like you mentioned the other day that you might have by today? DITTEMORE: Well, that -- the observation that was forwarded to us from California is important to us because this particular observer described -- as he was watching the Columbia pass overhead, he described what he believed was, in his mind, tile falling off the vehicle. Now whether it was tile or not, I don't know. But we're talking to him and trying to understand from his description what that could have been.

I don't know if there is any debris in California or Arizona and New Mexico. I do know that we found tile in Fort Worth. And so, the fact that we found a tile in the Fort Worth area, largely upstream of the debris field, maybe significant. I don't know yet.

Again, because the tile is light, its ability to travel downstream with the rest of the heavy material may have limited it to land into the Fort Worth/Dallas area rather than go all the way down into Lufkin and further. We're still looking at that.

I'm speculating a little bit if this observation on the West Coast was correct in his interpretation and if we judge it to be the case, if we truly were shedding some material as early as California, that's going to be significant to us. Again, I don't know that to be a fact and that's why we have a special team whose sole purpose is to investigate those reports and to interview the proper -- or interview the observers so that we can understand exactly what they're saying.

Now, we get reports from all over the country. So some of the reports are going to not be fruitful to us and others might be. So we're going through the process of eliminating those that aren't going to pay any dividend. And we're trying to isolate those that we think are more interesting and it's still too early for us to tell whether or not there's any findings in there that could be useful to us.

QUESTION: Phil Long (ph). Ron, could you share some more specifics about the meetings immediately following the day after the launch?

BLITZER: Ron Dittemore answering questions now for almost an hour. We're going continue to monitor this briefing and get some additional analysis.

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