CAIB Press Briefing Transcript 29 Apr 2003 (part 3)

A REPORTER: Okay. Because I’ve seen some interesting analysis of some of those pictures which indicates an irregularity outboard of the edge of one of the panels that could well still be a shadowing issue. It appears to be bigger than a pixel issue. It’s not done by the board or by NASA but by some private work that I thought was fairly visually interesting.

MR. TETRAULT: I haven’t seen that particular one, but what you saw there was only the tops of the RCC and, of course, we expect that the breach was really on the bottom sides.

A REPORTER: News 24 Houston. This question is for General Barry. In light of what Mr. Tetrault’s group is finding out that it’s more inboard, the breach, out of the seven test articles, which of these would still, in Admiral Gehman’s words, not necessarily agree but not conflict?

GEN. BARRY: Well, two we know certainly pass through the gates, as I mentioned, insofar as the radar cross-section is concerned and the mass-to-area ratio. One happens to be the T-seal that we did, complete T-seal. The second one has to do with kind of the glove insulation inside. We don’t really consider that to be a viable candidate even though it passed the RCS and the mass-to-area ratio because it’s inboard and something would have to breach the RCC and then have that thing come out, which is highly unlikely.

The remaining five are probable candidates. We have got the T-seal sections that we’re going to take form debris. We’ve got an RCC section that we’re going to take from debris. So indications right now are those could be viable candidates. We’ve got some preliminary information this week that the mass-to-area ratio is allowed for for both the RCC segment and the T-seal segment that we’re going to do. We’re waiting for the radar cross-section, but those testings should be complete this week. So by next week we should have an answer to your question.

A REPORTER: Fox 7 News out of Austin. This is to whoever wants to answer it. With regards to the testing taking place in San Antonio later this week, can you explain one more time exactly what is going to be done and what do you hope to show out of it, if you can talk specifics.

ADM. GEHMAN: Well, the testing is designed to indicate whether or not a foam strike of the size and the velocity that we saw on this particular event has the capacity to damage the leading edge system with sufficient damage to cause a hole that would initiate this event. Previous foam hits, of which there have been lots and lots of foam hits, have all done extraordinarily minor amount damage to the orbiter. So the question is would a foam strike of this size produce sufficient damage to initiate the event. Even if we do create damage on the test article that is of sufficient magnitude to initiate this event, that doesn’t prove it did it. It just proves it could have done it.

By the way, we have oversimplified to some degree what we’re talking about here. For example, I could pound on this table with a sledge hammer and not do any damage to the table but break a leg. Same thing could be true of the leading edge system. We could hit the outside of the leading edge system and not do any damage to it but we could break the support structure, break a bolt, break a pin, in which case we would have something flapping in the breeze which might come off later.

So we’re going to carefully instrument the inside of this target set so that we can, through analysis, better characterize all the ways that it could fail, not just a fracture to the RCC, even though that will be the most dramatic thing — I mean, that would be the thing you get the picture of — but we are going to have this carefully instrumented so that we can then infer all the ways that it could fail.

Roger, have I overstated that?

MR. TETRAULT: No, sir. That’s exactly what the concern is is the fastener system.

A REPORTER: How fast will that be fired?

ADM. GEHMAN: It will be about 650 feet per second, plus or minus 25, which equates to about 500 miles an hour, which is not something you would want to stand in front of, even if it is just foam.

LT. COL. WOODYARD: Okay. We’ll go to the phone bridge.

(Phone bridge not operational)

LT. COL. WOODYARD: All right. We’ll go back to Houston. A question right here.

A REPORTER: Thanks for a second bite at the apple.

Houston Chronicle. Both my questions have to do with foam. A couple of weeks ago you mentioned you were going to do a film audit and see if you could track down other events other than these four major foam losses, to see if there was anything in the launch record. I just wondered if that had turned up anything yet, and I’m still curious about how you’re going to deal with the possibility that the debris leaving the tank on the 107 launch was foam or foam plus ice or foam plus a piece of flange or ablator or something.

ADM. GEHMAN: We have been doing this audit of all the foam that was ever shed, and right now we have four events of known bipod shedding. Now, that doesn’t mean that’s all of them. As you are aware, some launches are at night and in some cases, as you may be aware, at ET separation, one of the things that the crews try to do very quickly is to jump up and take a picture of the ET as it comes off so we get a picture of that bipod foam. In some cases that didn’t occur for one reason or another. Sometimes the ET rotates and the bipod area is away from the orbiter so you don’t get a picture. So we don’t know. There are four known cases of the bipod breaking, and they didn’t all hit the orbiter. But there are launches at night and things like that. So we don’t know of that.

Now, the foam audit that we’re talking about refers to something else.

DR. RIDE: We have gone back and taken a look at what flights was there no visual, no ability to tell whether foam came off the bipod. From that we’ve concluded that, including 107, there were 5 out of 53 flights that had bipod foam loss. So in other words, on 53 flights, you can tell whether there was or wasn’t bipod foam.

ADM. GEHMAN: Including 107.

DR. RIDE: The others you can’t tell; you have no pictures of the bipod.

ADM. GEHMAN: Including 107.

DR. RIDE: Including 107.

ADM. GEHMAN: As far as the second part of your question, we don’t anticipate mixing ice or anything like that in with the foam. The way that you account for that is, you account for it by the kinetic energy of the bullet that you’re shooting. It doesn’t make any difference what adds to the kinetic energy, how you add mass to it. You just vary the kinetic energy and try to replicate the strike as best you can.

There are other issues, though. There are other technical issues actually which vary the results more than was there a little bit of ice or a lot of ice. One of those technical issues is at what angle did the foam hit the RCC, did it hit it on an edge or a blunt surface. Once again, whether I do this or whether I do that makes a lot of difference; and we haven’t quite wrestled that to earth yet. We might do it a couple of different ways to clock the angle around as to how it hits.

There’s another technical issue, too. That is the issue of a boundary layer condition. We’re going to shoot this at San Antonio level, sea level when these things come in contact with extraordinarily high speeds, there actually is a factor of cushioning caused by the air, which does not exist at 160,000 feet. So we also have to figure out how to account for that also.

That’s why this design of the test has taken so much time, because we think we’re only going to get a couple of shots because of lack of test articles. Once you hit a test article like this, it’s probably irrelevant to hit it again because you’ve done so much damage to it. So we are taking a considerable amount of time to design the test.

GEN. BARRY: To follow on to the question of what is the makeup of the actual debris hit. We’re not counting on it and it doesn’t look like it’s going to lend itself to a concrete answer, but spectral analysis is still ongoing on the film. We only have three colors that we can really discern that aids in the determination of what is the make-up of this thing. Obviously foam, the ablative material that was underneath the bipod, if there’s any metal that might have come off of that, we’re hoping, if anything, that the spectral analysis might give us a clue, but it’s going to be very limited at best and the indications right now is it’s not going to be very helpful. We’re still not concluding yet on that, but we’re hoping it’s going to give us an answer.

LT. COL. WOODYARD: We’re going to try the phone bridge one more time.

(Phone bridge not operational)

LT. COL. WOODYARD: Okay. We’re going to pass on the phone bridge. We apologize. It’s not working today.

A REPORTER: Florida Today. Probably for Admiral Gehman or maybe General Barry. Y’all mentioned that you’re really initiating an inquiry into the ascent and putting together a detailed time line. Of course, there’s the foam event at 81 seconds. I think Major General Barry had mentioned a gimbaling of the boosters around 62 seconds in response to an I-load. I wonder what else have you found out there in terms of the ascent and how this all might play into the whole big picture in terms of your investigation.

GEN. BARRY: Well, any single event you can’t conclude is the most determining. So there’s going to be a series of issues here that we’re going to try to put to bed.

First of all, as I mentioned, when you talk about the foam, it is the application and the voids and figuring out what the design element as well as the application was concerned. The mate, de-mate, and re-mate, how much that got shook. Then there was a crushed foam issue that was identified prior to launch.

Then we have on ascent. It looks like three out-of-experience issues here. Now out of experience is out of spec. It’s not out of tolerance. It’s not even out of family, using NASA’s terms. One certainly is a 61 seconds. We’re still trying to run that down because we see this as a solid rocket motor movement that is well within the capabilities of the solid rocket motor but it is right at max dynamic pressure to see if that is. There’s an indication from MADS and a few other things that there might be something at the beginning of launch and then towards the end, when the external tank separates. We’re still trying to run that down. So I qualify that as out of experience, not certainly out of spec or anything else.

Now, if you add all these combinations, including the cryopumping, can you arrive at the point where the bipod separates from the external tank? What we’re trying to do is say what, if any, of those incidents contributed to that single event. So we’re going to run down each one of these as we hopefully get to a concluding point, and then we’ll provide that in a report.

LT. COL. WOODYARD: One more question.

A REPORTER: Associated Press. (Barely audible) Along the same lines the ascent data from the OEX sensors on pressure and temperature blips that were unusual in the noise. Do you have any other words on that?

ADM. GEHMAN: That is exactly why we’ve announced this technical review with the same degree of detail that we have done on the entry. We have previously reported that nothing on ascent jumps out at you. On entry — this is from the OEX MADS recorder — on entry we had a couple of things that jumped right out at you. So we reported them right away.

Nothing on ascent leaps out at you as being startling, but there are some things which are going to bear close scrutiny. So I think really we’ve got to leave it at that point. What we said earlier remains today: Nothing on ascent jumps out at you. Nothing is out of spec or nothing went off line or rose or anything like that, but there were some little squiggles and things like that that we want to be sure that we account for, more from a point of view of completeness than anything else. More from a point of view of leaving no stone unturned that we think we can find something.

One of the reasons why this is coming up now is that the OEX recorder provides us more information, more relevant information to ascent than really the telemetry does — for example, all the strain gauges and things like that. So if there was a period of max dynamic loading and things like that, you might see it in the strain gauges. So we have a lot of things we have to add up together. It’s really premature to speculate that there is anything there. We really are doing this from the point of view of not missing anything rather than we smell a rat or something like that.

LT. COL. WOODYARD: I’m told the phone bridge is up. Can you hear me now?

A REPORTER: CBS. This is a question for Roger Tetrault. I just want to make sure I absolutely understand something. You were talking about the pattern of the slag blow-back, for lack of a better word I’ll use. I assume what you were saying, in trying to visualize the geometry, that that was consistent with a plume entry into the bottom half of RCC 8 that then hits the spar, causes some kind of melting damage, and blows some part of that back onto the inner surface of the RCC as it burns through the spar. A, Is that correct; and B, does moving slightly inboard change anything with respect to the border of the cable bundle that burnt through that were running on the outboard side of wheel well as you ultimately got into the wheel well itself.

MR. TETRAULT: With regard to the first one, you have, I think, correctly stated it except for the fact that it probably hit the Incoflex before it hit the spar and that was the first deposits that were made to the back of the RCC panels.

With regard to the cutting of the wires along the wheel well. Actually by moving a little bit further inboard, you actually close the distance between those wires that were cut on the spar versus the wires that were probably cut along the wheel well, and that makes it even more possible that the sequence works properly.

ADM. GEHMAN: By the way, all this has to be confirmed by a thermodynamic analysis, too. We’ve got all that work to do to see whether the temperatures and the times match up. So lots of work to be done here.

A REPORTER: Los Angeles Times. This is for Admiral Gehman. As you’ve held these various hearings, you’ve gotten a number of recommendations about what would improve the safety of the shuttle system and the management system at NASA. I noticed that today you mentioned that you had had some meetings with members of Congress and you’re going to have some additional ones. I’m wondering if, as you begin to deliberate about your findings and then your recommendations, whether fiscal realities will play a role in what you can recommend and, as part of that, if you could address whether you have requested or received any sort of cost briefings on what it would cost to implement certain kinds of changes that you might feel would be constructive. Thanks.

ADM. GEHMAN: The answer to your question is: We will not be constrained by costs. We probably would avail ourselves of technical information to determine whether or not one of our recommendations was even possible or even relevant or whether or not it was even humanly possible. Indeed, we may make ourselves aware of what things cost; but will not be constrained by costs.

If we come up with a series of recommendations which we believe would be prudent in order to continue safe manned space flight in the space shuttle vehicles and it ends up being too expensive for the nation to bear, so be it. It’s someone else has to make that decision.

LT. COL. WOODYARD: Next question on the phone bridge.

Okay. What we’ll do is we’ll conclude today’s press briefing. As always, our board members will remain for a brief period to answer any additional questions from Houston. Thank you all for coming.

(Conference concluded at 2:14 p.m.)