SPOKESMAN: When you find something, one whistle. That means everyone stops, all right?
TERENCE SMITH: For a third day, search crews fanned out across eastern Texas and Louisiana, hunting for remnants of the space shuttle "Columbia." So far, teams from local and federal agencies and volunteers have found about 2,000 sites where debris has fallen in an area up to one hundred and twenty miles long and ten miles wide. In Nacogdoches County in eastern Texas, local authorities have been overwhelmed trying to secure debris sites, some of which include remains of the seven astronauts who were lost when the shuttle broke apart Saturday morning.
THOMAS KERSS, Nacogdoches County Sheriff: We have received approximately six more unconfirmed reports of sites that may contain human remains. We're in the process of trying to investigate those sites now. They still remain a top priority. Yesterday I was unwilling to confirm for you, but did acknowledge that we have received a report that a large section of debris approximately six to seven feet in length, had been located and some of you were asking was that a piece of the cabin component. I will tell you that we did locate a section of the cabin here in Nacogdoches County that was approximately that size.
TERENCE SMITH: At a briefing in Washington this morning, NASA authorities said the debris field is more extensive than they originally thought.
MICHAEL KOSTELNIK: It turns out that the debris field is quite large and still really being determined today. We find that there are more things further West than we anticipated. We're establishing a second NASA command post in the area of Carswell Air Force base to facilitate those things near the Fort Worth area.
TERENCE SMITH: The most immediate and pressing task, authorities said, is to recover human remains.
MICHAEL KOSTELNIK: We have a lot of activity ongoing today. There is, again, the focus on the recovery of human remains, mostly in the Lufkin area, mostly with the FBI and EPA teams in concert with the NASA representatives. These will be augmented in terms of protecting the physical sites for material as located by the Texas National Guard.
TERENCE SMITH: NASA associate administrator Bill Readdy said investigators still don't know what caused Saturday's tragedy, but attention is being paid to a piece of foam that struck the orbiter's left wing during liftoff last month.
BILL READDY: That is one of the things that we're looking at, and everybody seems to have leaped to the conclusion that that was the cause. And I'm not sure that we're ready to say that. And an accident incident investigation, you start out by ruling out things, rather than ruling them in. And although that may in fact wind up being the cause, it may certainly be the leading candidate right now, we have to go through all the evidence and then rule things out very methodically in order to arrive at the cause. But in fact, on the 12th day mission report, that's the one I quoted to you that talked about the thermal analyses indicated localized structural damage, but no burn-through and no safety flight issue. But it was assessed continuously during the flight by expert panel.
TERENCE SMITH: At the White House today, NASA's director Sean O'Keefe briefed Pres. Bush on the shuttle disaster. Later, during a speech at the National Institutes of Health, Pres. Bush honored "Columbia's" crew members.
PRES. GEORGE W. BUSH: Two days ago America was yet reminded again of the sacrifices made in the name of scientific discovery. The seven brave men and women from the "Columbia" will be remembered for their achievements, their heroism, and their sense of wonder.
TERENCE SMITH: On Capitol Hill late this afternoon, O'Keefe briefed members of Congress. A number of congressional committees are expected to hold hearings on the shuttle disaster. Late this afternoon in Houston, NASA shuttle program manager Ron Dittemore provided a revised look at the last several minutes of flight.
RON DITTEMORE: 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 temperature measurements rose significantly.
Yesterday, I reported 20 to 30 degrees increasing 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. 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 surface 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 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 pore 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 appeared 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. So again, there is certainly an interest in the wheel well. I'll 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. But again we're early in this investigation and we're still poring 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.
TERENCE SMITH: Dittemore said NASA is conducting computer models to simulate the damage that occurred at liftoff.
RON DITTEMORE: The debris is not going to hit the under side 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 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 both 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 a single tile at the main landing gear door and for the other case where you had more acreage damaged, 32 by seven by two-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.
TERENCE SMITH: Dittemore said investigators are still struggling to find what he described as a "missing link" that would explain what caused the shuttle to break apart.