MR. MORALES: It was a routine science mission. But just minutes before Columbia was to land in Florida, all communications were lost. The shuttle became a fireball, streaking across the Texas sky at 18 times the speed of sound . . . more than 60-thousand meters above the earth. All seven astronauts onboard perished in America's worst space disaster since the shuttle Challenger exploded on lift-off in 1986.

As the nation mourns, Americans are asking how it could have happened.

Joining me to examine the Columbia tragedy are: James Oberg -- a former space shuttle engineer for NASA and an expert on space disasters. He joins us from Houston, Texas. And John Logsdon, Director of the Space Policy Institute at The George Washington University here in the nation's capitol.

James Oberg, let me begin with you. Can we expect this investigation to be similar to the one that followed the Challenger disaster 17 years ago?

MR. OBERG: I think in the thoroughness we need to expect it to be that thorough, but I don't expect to find a fundamental design flaw, because they have a much longer flight experience, especially with more than 100 successful entries in the past. That being the case, the kind of accident and the kind of results from this accident, may be more like Apollo 13, where processing flaws were found to be the cause, and the system was recertified to fly in less than a year. Instead, with Challenger, there were fundamental design flaws that had to be redesigned, verified, tested, and installed, and that took almost three years.

MR. MORALES: John Logsdon, let me put that same question to you. What will this investigation look like?

MR. LOGSDON: I think it's going to look different than the Rogers Commission investigation of the Challenger accident. There was a fair amount of political theater associated with the Rogers Commission, big public hearings and kind of dramatic -- Richard Feynman dropping rubber into an icy glass to show it was getting hard. The people that have been assigned responsibility for doing this investigation are mainly people inside the government, chaired by a very solid guy, who I happen to know, retired Admiral Harold Gehman. They're going to bore into the data, do deep technical analysis, really, as quickly as possible, get to the core of what caused this.

MR. MORALES: John Logsdon, what do you see as the special challenges for investigators of this particular disaster?

MR. LOGSDON: You have the physical evidence scattered across a number of States in lots of little pieces. How much contribution the physical evidence is going to be able to make to what went wrong is a questionable sort of issue. Where with Challenger the engineers even on the Shuttle program knew within a day or two rather clearly that it was the o-ring that has caused the problem, there was really no hard job of figuring out the basic problem. The question then was how to fix it.

MR. OBERG: The special challenge of course is that the material -- that the vehicle came apart at a tremendous altitude and speed and that the fragments are scattered and damaged on the way down -- so getting that material is going to be a challenge, if not impossible -- getting all of it. And finding the key pieces, the pieces that were damaged first or that broke first, may never happen.

MR. MORALES: Congress and the administration are expected to play crucial roles in trying to find out what happened with the Space Shuttle. How do you see Congress and the White House taking a part in all of this?

MR. LOGSDON: Well, the White House I think will allow NASA and the external review committee that has already been appointed to go about their work in a technically sound and unpolitical way. So, I think the White House will oversee that process but not deeply intervene in it.

Congress being Congress will feel it has to exercise its oversight, and so there will be hearings, there will be almost certainly some posturing. But also I think the members of Congress will very much seriously want to get to the bottom of what this problem was and try to understand whether NASA has done an adequate job with Shuttle safety, which a lot of people are questioning right now, and whether an adequate budget has been provided for the program overall and particularly for the Shuttle safety program.

MR. MORALES: James Oberg, that raises a question of the budget. There are press reports that -- well, they're speculating -- that budget cuts at NASA over the 1990's might have compromised safety at the agency. Given NASA's mission, can NASA fulfill its mission on its current budget?

MR. OBERG: It's not just speculation. Remember, an independent review board that NASA has set up have raised a very specific issue, that they did not think that, under the cutback environment, safe operations would be possible. But the question still remains, is that in fact the cause of this accident? Is this in fact an accident or merely the consequence of bad maintenance? Let's try and find that out before rushing to use this disaster as confirmation of our own pet theories.

MR. MORALES: We have just about a minute left, and I would like to ask each of you, beginning with James Oberg, with the Challenger disaster in 1986 and now the loss of the Columbia, where does NASA go from here?

MR. OBERG: NASA has already said that it would like to supplement the Shuttle fleet with a smaller crew transfer vehicle, up into orbit and back, for four to six astronauts. The Europeans are building a supply vehicle, a large one. The Russians still have their own design. The Chinese even have a manned vehicle that can also be a supply ship. The Shuttles have been primarily required for the construction of the Station, carrying the large elements. Over the coming years, as the Station construction is complete, the actual need for a great many Shuttle flights will be reduced. Shuttles may be available for other missions. There will still be a need to fly them at least once or twice a year to keep everyone in practice. But it might well be that there will come a time when even the need for this large a vehicle, with this large a payload bay, will no longer be so pressing. Three vehicles is enough. Two might be enough. If you're ever down to one, it is time to start building a replacement.

MR. MORALES: And John Logsdon?

MR. LOGSDON: We've lost the oldest orbiter, which did not have as a primary mission going to Station. So, I think that the three existing orbiters are perfectly enough capacity, once they begin flying again, to get the Station assembled. There is this proposal to create something called an orbital space plane, in the early years of the next decade, which would take over a lot of the crew transfer responsibilities from the Shuttle. So, I think there was a strategy put in place that, if followed, will allow the U.S. to have continued access for humans to space into the indefinite future.

MR MORALES: We'll have to leave it there. I would like to thank my guests: space engineer James Oberg and John Logsdon, Director of the Space Policy Institute at The George Washington University.