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American Morning

Interview with Former NASA Engineer

Aired February 03, 2003 - 07:06   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.


PAULA ZAHN, CNN ANCHOR: Back to our lead story this morning, more details on what happened during Columbia's final minutes. At 8:53 a.m. Eastern Time, temperature measurements in parts of the left wing rise 30 degrees as the shuttle flies over California. One minute later, over western Nevada, the temperature in the left side of the fuselage jumps 15 degrees. At 8:58 over New Mexico, the shuttle pitches left and drag increases on the left wing. Then at 8:59 a.m. over Texas, one minute before NASA loses contact with the crew, pressure readings in the left wing's tire fail. A minute later, the Columbia was gone.
Joining us now from Atlanta, Randy Avera, a former NASA engineer who helped to investigate the Challenger disaster. He's also written a book called, "The Truth About Challenger."

Thanks so much for being with us this morning, Randy.

RANDY AVERA, CHALLENGER INVESTIGATOR: Good morning.

ZAHN: Let's talk about the increased focus on the left wing, and what we are learning from what NASA officials told us. Let's take a look at the picture of Columbia upon launch, where we're going to try to, with the help of this Telestrator, isolate a piece of debris falling from one of the rockets right there, onto what appears to be the left wing of the Columbia. What can we glean from this?

AVERA: Well, obviously, it's a bright object. NASA believes that it's part of the insulation off of the external tank. What we learned in 1986 in the Challenger crash investigation is that video can be very misleading, but it is a piece of data that you include with the whole analysis to determine what the cause of the crash could be, or if there are combinations of failures and multiple malfunctions that may have occurred.

ZAHN: We know that NASA has confirmed they checked out the wing in space, decided not to take pictures of it because they didn't find it remarkable. Was that a mistake?

AVERA: Well, the tile system is essentially a delicate system. It's 1960's, early '70s design. NASA currently has programs to develop new, more durable insulation systems for re-entry vehicles, but that's one of the areas that we need to put a lot of focus in our scientific research and development. We've compared it to a butterfly mounted to a bullet, the orbiter and its systems on board, its structure and some of its systems like the thermal protection system, which includes those high temperature tiles. ZAHN: Let's talk about those, what appear to be thermal problems. The temperature rising dramatically in the left wing and left side of the shuttle. What should that indicate?

AVERA: The condition in that left main wheel well, if you think of the two main landing wheel wells and landing gear that are located towards the rear and the bottom of the orbiter, those temperatures are higher than expected and higher than known in the past flight history. And that rise in temperature, obviously that heat came from some source. What NASA is going to be doing is sorting out all of the details, looking at the evidence to determine the source of that heat and what effect it had on the safe flight and approach to the landing area in Florida. As you know, it didn't make it past Louisiana, because of ultimately loss of flight control and the catastrophic stress on the vehicle.

ZAHN: We know yesterday and NASA confirming that before loss of contact, the shuttle banked to the left. And the administrator said that may indicate missing tiles on the left wing or a rough tile on the left side of the shuttle. Walk us through that.

AVERA: Well, the computers there are what are called "general purpose computers." They're basically the brain of the orbiter. And they not only control during boost to orbit on the launch day, but also the re-entry into the earth's atmosphere, which starts with the de-orbit burn about 45 minutes before landing. The computer is actually controlling the orbiter down through the atmosphere. As you see in the graphic, the pitch-over that's being conducted by the computer, and then it will ultimately pitch up to about a 40-degree positive angle for the proper attitude for the entry and to accommodate all of the friction due to heat of re-entry. You're treading at a tremendous speed of 1,750 miles per hour, exchanging that energy for energy of heat. And you're going to dissipate that energy, so you can slow down for a landing at 212 miles per hour at the end.

ZAHN: Finally this morning, Randy, what are we going to learn from the last 32 seconds of the data?

AVERA: This 32 seconds that NASA has been talking about yesterday, this is telemetry data, sensors on board the orbiter that has been monitoring and measuring data. The audio drop-out that we are familiar with, that being the conversation between the astronauts and mission control in Houston, that audio drop-out, what NASA is really saying is that they believe there are about 32 more seconds of data. These sensors have what's called a "sample rate." Imagine a temperature measurement being sampled at say 30 times a second...

ZAHN: Wow!

AVERA: ... or another one being at 200 times a second of a sample rate. So, that's what they're looking at is this recorded data on the ground to see if there is any data that will be valuable in figuring out the puzzle of what happened on that day.

ZAHN: Well, you've been very valuable to us this morning as we try to sort through what all of this very complicated information means. Randy Avera, thank you for your time this morning.

AVERA: You're welcome.

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 February 3, 2003 - 07:06   ET
THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.
PAULA ZAHN, CNN ANCHOR: Back to our lead story this morning, more details on what happened during Columbia's final minutes. At 8:53 a.m. Eastern Time, temperature measurements in parts of the left wing rise 30 degrees as the shuttle flies over California. One minute later, over western Nevada, the temperature in the left side of the fuselage jumps 15 degrees. At 8:58 over New Mexico, the shuttle pitches left and drag increases on the left wing. Then at 8:59 a.m. over Texas, one minute before NASA loses contact with the crew, pressure readings in the left wing's tire fail. A minute later, the Columbia was gone.
Joining us now from Atlanta, Randy Avera, a former NASA engineer who helped to investigate the Challenger disaster. He's also written a book called, "The Truth About Challenger."

Thanks so much for being with us this morning, Randy.

RANDY AVERA, CHALLENGER INVESTIGATOR: Good morning.

ZAHN: Let's talk about the increased focus on the left wing, and what we are learning from what NASA officials told us. Let's take a look at the picture of Columbia upon launch, where we're going to try to, with the help of this Telestrator, isolate a piece of debris falling from one of the rockets right there, onto what appears to be the left wing of the Columbia. What can we glean from this?

AVERA: Well, obviously, it's a bright object. NASA believes that it's part of the insulation off of the external tank. What we learned in 1986 in the Challenger crash investigation is that video can be very misleading, but it is a piece of data that you include with the whole analysis to determine what the cause of the crash could be, or if there are combinations of failures and multiple malfunctions that may have occurred.

ZAHN: We know that NASA has confirmed they checked out the wing in space, decided not to take pictures of it because they didn't find it remarkable. Was that a mistake?

AVERA: Well, the tile system is essentially a delicate system. It's 1960's, early '70s design. NASA currently has programs to develop new, more durable insulation systems for re-entry vehicles, but that's one of the areas that we need to put a lot of focus in our scientific research and development. We've compared it to a butterfly mounted to a bullet, the orbiter and its systems on board, its structure and some of its systems like the thermal protection system, which includes those high temperature tiles. ZAHN: Let's talk about those, what appear to be thermal problems. The temperature rising dramatically in the left wing and left side of the shuttle. What should that indicate?

AVERA: The condition in that left main wheel well, if you think of the two main landing wheel wells and landing gear that are located towards the rear and the bottom of the orbiter, those temperatures are higher than expected and higher than known in the past flight history. And that rise in temperature, obviously that heat came from some source. What NASA is going to be doing is sorting out all of the details, looking at the evidence to determine the source of that heat and what effect it had on the safe flight and approach to the landing area in Florida. As you know, it didn't make it past Louisiana, because of ultimately loss of flight control and the catastrophic stress on the vehicle.

ZAHN: We know yesterday and NASA confirming that before loss of contact, the shuttle banked to the left. And the administrator said that may indicate missing tiles on the left wing or a rough tile on the left side of the shuttle. Walk us through that.

AVERA: Well, the computers there are what are called "general purpose computers." They're basically the brain of the orbiter. And they not only control during boost to orbit on the launch day, but also the re-entry into the earth's atmosphere, which starts with the de-orbit burn about 45 minutes before landing. The computer is actually controlling the orbiter down through the atmosphere. As you see in the graphic, the pitch-over that's being conducted by the computer, and then it will ultimately pitch up to about a 40-degree positive angle for the proper attitude for the entry and to accommodate all of the friction due to heat of re-entry. You're treading at a tremendous speed of 1,750 miles per hour, exchanging that energy for energy of heat. And you're going to dissipate that energy, so you can slow down for a landing at 212 miles per hour at the end.

ZAHN: Finally this morning, Randy, what are we going to learn from the last 32 seconds of the data?

AVERA: This 32 seconds that NASA has been talking about yesterday, this is telemetry data, sensors on board the orbiter that has been monitoring and measuring data. The audio drop-out that we are familiar with, that being the conversation between the astronauts and mission control in Houston, that audio drop-out, what NASA is really saying is that they believe there are about 32 more seconds of data. These sensors have what's called a "sample rate." Imagine a temperature measurement being sampled at say 30 times a second...

ZAHN: Wow!

AVERA: ... or another one being at 200 times a second of a sample rate. So, that's what they're looking at is this recorded data on the ground to see if there is any data that will be valuable in figuring out the puzzle of what happened on that day.

ZAHN: Well, you've been very valuable to us this morning as we try to sort through what all of this very complicated information means. Randy Avera, thank you for your time this morning.

AVERA: You're welcome.

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