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Interview With Fmr. Shuttle Engineer Randy Avera

Aired May 30, 2003 - 15:36   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.


MILES O'BRIEN, CNN ANCHOR: Even while the space shuttle Columbia was still in flight, a few engineers at NASA expressed concern about the foam falling off the external tank, which happened right after the launch. And as that investigation continues into what happened to Columbia on February 1, the disintegration which killed the entire crew, there is additional evidence, perhaps approaching smoking gun evidence, that that foam falling on the leading edge of the wing was the root cause of this accident.
Joining me to talk a little about what has been uncovered by the Columbia Accident Investigation Board and what lies head, Randy Avera, retired NASA engineer.

Randy, good to have you back with us.

RANDY AVERA, FMR. SHUTTLE ENGINEER: Good to see you, miles.

O'BRIEN: All right.

The testing -- and we're going to roll a little tape and show some high speed photography of just how they've been doing this. San Antonio, Texas, is the location. They've been taking an air cannon, essentially, and they've been firing a pound and two third pieces of foam at a 20-degree angle against a wing mock-up, reasonable facsimile of what happened about 80 seconds after launch, right?

AVERA: Yes.

This special test that was conducted recently was on a component that came from the prototype to the orbiters, as you may recall, the Enterprise, which is a museum piece in the Smithsonian in Washington, D.C. The leading edge panel on that vehicle is a fiberglass panel, not the reinforced carbon carbon.

But this is an important test because what it was intended to look for was if you impact this leading edge panel with a certain mass of an object at a certain velocity, what is the effect of those components on the leading edge? It was predicted that the T-seal, the small piece of reinforced carbon carbon that spaces between the large reinforced carbon carbon panels of an orbiter, that it would dislodge that leading edge T-seal and, in fact, that was the result that they found in the special test. That it, in fact, did dislodge up to as much as a quarter of an inch to create a gap where, if you were in flight, it would allow aerodynamic flow through the gap. O'BRIEN: All right. Let's orient people because we're talking -- as usual, there's a fair amount of terminology we've got to get through here.

AVERA: Yes.

O'BRIEN: We're talking about this leading edge area here, which it's important, because it's one of the hottest places when a space shuttle returns, approaching 3,000 degrees.

The material is a composite material, reinforced carbon carbon. It's a series of little pieces that are kind of U-shaped. And in between them, they have the T-seal spacers. And what happened in this test, which was very intriguing to the investigators was when that piece of foam struck there, it kind of disturbed that T-seal enough to create this 22-inch seam, if you will. Now, 22-inch seam with thickness of a dime, all the way up to a quarter of an inch, as you put it, would not sound like a lot. But when you're coming in at these hypersonic speeds with 3,000 degree heat and aluminum underneath here, which has a melting point of -- I don't know -- a little over 1,000 degrees, you're talking about -- might as well be a barn door wide open, right?

AVERA: Yes. The very hot temperatures -- it doesn't actually have to melt the aluminum in order to fail it. It can actually heat it up to what's called a plastic state, where the actual wing could distort and come apart due to that.

But these temperatures are well above the plastic state. It's well into the melting state of those materials.

O'BRIEN: And now, the other interesting thing that was pointed out is that this material used on the Enterprise, which was, after all used only to test the glide capability of the shuttle, not the space characteristics -- that leading edge material didn't need to be reinforced carbon carbon to protect it from heat. It was just fiberglass. And fiberglass, as it turns out, is a little more resilient than the reinforced carbon carbon.

So are we getting to the point now where these investigators can stand up and say, beyond a shadow of a doubt, that this is the cause? Or is it still going to be -- I know you work in another realm, closely with the NTSB, the National Transportation Safety Board, where they'll say, This is probable cause?

AVERA: At this point, the accident investigation board for Columbia is not stating an exact cause and they, in fact, are orbiting around what appears to be more like a probable cause.

Certainly, the leading edge of the wing was a failed area. Certainly, the foam strike did have an effect on that. That's a known piece of evidence. But the board is currently putting their preliminary report together and later in the summer will have the final report, where it will detail not only this area, but other areas of the shuttle program as well. O'BRIEN: All right. The question which has been on my mind all day today was, NASA saw foam fall off external tanks several times over the years. You've got to wonder why a test like this one, which was so clear-cut, was not conducted years ago.

AVERA: In the early stages of a developmental program, it's important to remember a couple of things. NASA's a research and development agency. The space shuttle in the 1960s and '70s was a new concept.

And when I think back to those years, the thermal protection system, which is what that leading edge is more considered, it was -- there was a tremendous amount of effort spent in the thermal aspects of that. But when we talk about the structural aspects of insulators that go on the outside of the vehicle, it's obvious that NASA has its work cut out. It's time for the engineers and scientists and technicians to go to work and solving the technical problems. That's what NASA's all about: finding a technical problem, researching it, developing it, coming up with new products, materials and procedures. That's what, clearly, NASA has ahead of it.

O'BRIEN: All right. Randy Avera, our analyst, retired NASA engineer who extensively on the shuttle program over the years.

Thanks as always for your insights. We appreciate it.

AVERA: You're welcome, Miles.

TO ORDER A VIDEO OF THIS TRANSCRIPT, PLEASE CALL 800-CNN-NEWS OR USE OUR SECURE ONLINE ORDER FORM LOCATED AT www.fdch.com







Aired May 30, 2003 - 15:36   ET
THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.
MILES O'BRIEN, CNN ANCHOR: Even while the space shuttle Columbia was still in flight, a few engineers at NASA expressed concern about the foam falling off the external tank, which happened right after the launch. And as that investigation continues into what happened to Columbia on February 1, the disintegration which killed the entire crew, there is additional evidence, perhaps approaching smoking gun evidence, that that foam falling on the leading edge of the wing was the root cause of this accident.
Joining me to talk a little about what has been uncovered by the Columbia Accident Investigation Board and what lies head, Randy Avera, retired NASA engineer.

Randy, good to have you back with us.

RANDY AVERA, FMR. SHUTTLE ENGINEER: Good to see you, miles.

O'BRIEN: All right.

The testing -- and we're going to roll a little tape and show some high speed photography of just how they've been doing this. San Antonio, Texas, is the location. They've been taking an air cannon, essentially, and they've been firing a pound and two third pieces of foam at a 20-degree angle against a wing mock-up, reasonable facsimile of what happened about 80 seconds after launch, right?

AVERA: Yes.

This special test that was conducted recently was on a component that came from the prototype to the orbiters, as you may recall, the Enterprise, which is a museum piece in the Smithsonian in Washington, D.C. The leading edge panel on that vehicle is a fiberglass panel, not the reinforced carbon carbon.

But this is an important test because what it was intended to look for was if you impact this leading edge panel with a certain mass of an object at a certain velocity, what is the effect of those components on the leading edge? It was predicted that the T-seal, the small piece of reinforced carbon carbon that spaces between the large reinforced carbon carbon panels of an orbiter, that it would dislodge that leading edge T-seal and, in fact, that was the result that they found in the special test. That it, in fact, did dislodge up to as much as a quarter of an inch to create a gap where, if you were in flight, it would allow aerodynamic flow through the gap. O'BRIEN: All right. Let's orient people because we're talking -- as usual, there's a fair amount of terminology we've got to get through here.

AVERA: Yes.

O'BRIEN: We're talking about this leading edge area here, which it's important, because it's one of the hottest places when a space shuttle returns, approaching 3,000 degrees.

The material is a composite material, reinforced carbon carbon. It's a series of little pieces that are kind of U-shaped. And in between them, they have the T-seal spacers. And what happened in this test, which was very intriguing to the investigators was when that piece of foam struck there, it kind of disturbed that T-seal enough to create this 22-inch seam, if you will. Now, 22-inch seam with thickness of a dime, all the way up to a quarter of an inch, as you put it, would not sound like a lot. But when you're coming in at these hypersonic speeds with 3,000 degree heat and aluminum underneath here, which has a melting point of -- I don't know -- a little over 1,000 degrees, you're talking about -- might as well be a barn door wide open, right?

AVERA: Yes. The very hot temperatures -- it doesn't actually have to melt the aluminum in order to fail it. It can actually heat it up to what's called a plastic state, where the actual wing could distort and come apart due to that.

But these temperatures are well above the plastic state. It's well into the melting state of those materials.

O'BRIEN: And now, the other interesting thing that was pointed out is that this material used on the Enterprise, which was, after all used only to test the glide capability of the shuttle, not the space characteristics -- that leading edge material didn't need to be reinforced carbon carbon to protect it from heat. It was just fiberglass. And fiberglass, as it turns out, is a little more resilient than the reinforced carbon carbon.

So are we getting to the point now where these investigators can stand up and say, beyond a shadow of a doubt, that this is the cause? Or is it still going to be -- I know you work in another realm, closely with the NTSB, the National Transportation Safety Board, where they'll say, This is probable cause?

AVERA: At this point, the accident investigation board for Columbia is not stating an exact cause and they, in fact, are orbiting around what appears to be more like a probable cause.

Certainly, the leading edge of the wing was a failed area. Certainly, the foam strike did have an effect on that. That's a known piece of evidence. But the board is currently putting their preliminary report together and later in the summer will have the final report, where it will detail not only this area, but other areas of the shuttle program as well. O'BRIEN: All right. The question which has been on my mind all day today was, NASA saw foam fall off external tanks several times over the years. You've got to wonder why a test like this one, which was so clear-cut, was not conducted years ago.

AVERA: In the early stages of a developmental program, it's important to remember a couple of things. NASA's a research and development agency. The space shuttle in the 1960s and '70s was a new concept.

And when I think back to those years, the thermal protection system, which is what that leading edge is more considered, it was -- there was a tremendous amount of effort spent in the thermal aspects of that. But when we talk about the structural aspects of insulators that go on the outside of the vehicle, it's obvious that NASA has its work cut out. It's time for the engineers and scientists and technicians to go to work and solving the technical problems. That's what NASA's all about: finding a technical problem, researching it, developing it, coming up with new products, materials and procedures. That's what, clearly, NASA has ahead of it.

O'BRIEN: All right. Randy Avera, our analyst, retired NASA engineer who extensively on the shuttle program over the years.

Thanks as always for your insights. We appreciate it.

AVERA: You're welcome, Miles.

TO ORDER A VIDEO OF THIS TRANSCRIPT, PLEASE CALL 800-CNN-NEWS OR USE OUR SECURE ONLINE ORDER FORM LOCATED AT www.fdch.com