Shuttle Foam Problem Stymies NASA Though the space shuttle Discovery has succesfully docked with the international space station, NASA managers have announced that the shuttle fleet will again be grounded to deal with the problem of falling foam chunks. Joe Palca leads a discussion on the problems with the shuttle.
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Shuttle Foam Problem Stymies NASA

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Shuttle Foam Problem Stymies NASA

Shuttle Foam Problem Stymies NASA

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JOE PALCA, host:

This is TALK OF THE NATION/SCIENCE FRIDAY from NPR News. I'm Joe Palca. Ira Flatow is away.

The space shuttle Discovery is in orbit, linked up with the International Space Station. This was supposed to be a week of celebration for NASA, a return to flight for the shuttles after a two-and-a-half-year delay. But cameras watching the Tuesday launch saw something they didn't want to see: a chunk of debris, most likely foam insulation, flaking off from the shuttle's external fuel tank. It's the kind of flaw thought to be responsible for the damage that led to the Columbia disaster. This time, at least, the foam debris didn't appear to strike the shuttle, so NASA engineers don't think Discovery is threatened, but they have grounded the shuttle fleet again as engineers look for a solution to a problem they thought they had under control.

Joining me now is Frank Morring. He's the senior space technology editor for the publication Aviation Week and Space Technology based in Washington, DC. He's actually in Houston today, where he joins us.

Thanks for being with us today.

Mr. FRANK MORRING (Senior Space Technology Editor, Aviation Week and Space Technology): You're welcome.

PALCA: And if you'd like to join the conversation, give us a call. Our number is 800-989-8255. That's 1-800-989-TALK. And if you want more information about what we're talking about this hour, go to our Web site at www.sciencefriday.com, where you'll find links to our topic.

So, Frank Morring, I gather that there's even possibly been more chunks of foam debris, they think, than the original one that seemed to have come off now they've reanalyzed some of the pictures of liftoff.

Mr. MORRING: That's right. They have a few more that they've seen that are bigger than the allowable size they had planned for. But the one that they're really worried about is the one that weighed almost a pound that came off an area that they had decided not to work on because they thought they understood what was keeping the foam stuck to the tank there.

PALCA: So this is a different place than the foam that broke off that actually wound up punching a hole in the wing in Columbia and caused that to burn up on entry.

Mr. MORRING: That's right, but it's the same kind of foam. The foam that brought down Columbia and the foam that they saw on launch this week were both hand-applied foam ramps designed to protect structure from the aerodynamic pressures that the tank encounters during the ascent, which gets pretty fast.

PALCA: I see. So by ramp--I mean, I was trying to picture this. It's not something that you walk up, obviously, but it's a raised slope to cover a bunch of cables, I think, or at least tubing that carry--carries liquid--or maybe it is cables. I'm not sure.

Mr. MORRING: It protects cables, that's right.

PALCA: Yeah.

Mr. MORRING: It protects cables from the wind, basically.

PALCA: Yeah. So where does this leave NASA? They obviously had done some analyses. They thought they solved the problem. But clearly, they have not. What more can they do?

Mr. MORRING: Well, actually, we just had a conversation with Richard Covey, the astronaut that was appointed to kind of look over NASA's shoulder as they prepared to return to flight. And basically, they didn't understand what happened. They thought that the foam came off because of voids, small spaces, inside the hand-applied areas that allowed gas and liquid to expand as the flight continued and literally popped pieces of foam off. They're pretty sure that's what happened to Columbia. In this case, they had X-rayed this area. They didn't see any voids and the foam still came off. So they're--they need to have a better understanding of what Covey called the physics of this phenomenon.

PALCA: Yeah, yeah. And, you know, there's been a suggestion that if you look you'll find. I mean, they've been watching this from all kinds of spectacular angles, including a camera mounted on the external fuel tank. Some have suggested that this, you know, foam may have popped off before and just nobody ever saw it because the external fuel tank burns up on re-entry.

Mr. MORRING: That's right. They--in fact, this piece of foam coming off was actually seen with that camera you just mentioned. They have a lot more data than they've ever had on the condition of the shuttle after it reaches space, and they've seen a lot more. They're actually kind of pleased. They say that there's about a factor of six less damage to the shuttle, and they've been looking at the shuttle very carefully from a lot of different angles since it lifted off and continuing in orbit.

PALCA: I got it. So in the meantime, they're still staying with the explanation that whatever flaked off didn't seem to hit the shuttle and they don't think Discovery's in any kind of danger.

Mr. MORRING: No, they don't. They think it's--they haven't completely cleared it for landing, but they--so far, they haven't found anything that's startling to them. And today, they went back and did what they call focused inspections with a sensor mounted on a long boom that can basically see just about the whole space shuttle, and they didn't see anything, as far as I know, that troubled them.

PALCA: OK. Well, let's invite our listeners to join this conversation. Our number's 800-989-TALK. That's 800-989-8255. And why don't we go to, let's see, Matt.

Matt in Lawrence, Kansas, welcome to the program.

MATT (Caller): Hey. I've had a question for a while. How come they don't just put either some kind of Kevlar netting or chopped Kevlar long fiber in the foam as they're applying it? And wouldn't that solve the problem of pieces fracturing?

PALCA: Interesting. Frank, do you have any ideas on that?

Mr. MORRING: Not really. That--they--I believe they have looked at netting. I don't know why they didn't use it, although weight might be a consideration.

PALCA: OK. Well, Matt, it sounds like an interesting idea. And, believe me, if NASA decides to adopt that, we'll call back, OK?

MATT: All right, then.

PALCA: Thanks very much.

Let's take another call now. Let's go to Jerry in Baltimore.

Jerry, welcome to the program.

JERRY (Caller): Hi. One of the strangest things--I didn't hear the actual text of the interview, but the flight commander said, `I thought NASA had solved that problem.' And it was a reflexive comment. She must have been assured that there was no problem, and, clearly, there is. How serious, we don't know. I'd like to hear your guest, Joe, if he heard that interview, explain the spontaneous remark that indicated or caused me great concern about the program.

PALCA: Interesting. Thanks for that call, Jerry. What about that, Frank Morring? Do you think that Eileen Collins, the commander of the mission, was not told all the information?

Mr. MORRING: I'm pretty sure she knew as much about the condition of the shuttle as anyone did when she lifted off. I think everyone at NASA was surprised that a piece this large came off. They thought they had solved the problem and they admitted up front that they were wrong.

PALCA: Yeah. Is this going to have any impact on the mission that they're supposed to be carrying out? They're obviously--they're at the space station now. They have a space walk planned for tomorrow where they're going to test some of these new repair things they were going to try out if a piece of foam--I mean, a piece of insulating tile came off or something. But what about other things? Can they do anything that will help them for the future?

Mr. MORRING: Actually, they're studying right now, if they can extend the mission by one day, to better prepare the space station for another hiatus in deliveries by the space shuttle. They can still get supplies via Russian progress vehicles and crews can still ride the Soyuz vehicles up and down, but they're going to try to do as much as they can. They mentioned a few specific things. They're going to leave a couple of laptops from the shuttle. Those things tend to wear out pretty fast in space, and so they're going to leave the Discovery laptops on board. They may even move some food over and extra water, more water than they had planned. But they're also going to carry out their original mission plan.

PALCA: Yeah, yeah. It doesn't sound like they--I mean, it sounded like they were pretty packed up to start with when they launched. It didn't sound like they had a lot of extra stuff to leave behind.

Mr. MORRING: That's right.

PALCA: So--and does NASA--I mean, I guess they're in the mode of wait and see at the moment, but they're not saying how long they think the fleet might have to stand down, are they?

Mr. MORRING: No, they're not. And, of course, they've been getting that question regularly. The next flight--the next window for a shuttle flight is opening on September 9th. That doesn't give them a lot of time. It's taken them two and a half years to get to this point. And while they're not saying that it's going to take another two and a half years to figure out why this piece of foam came off, it's beginning to look like the September launch window is going to be really difficult to hit.

PALCA: OK. Let's take another call now. And let's go to David in Miami. Welcome to the program, David.

DAVID (Caller): Hello. It's good to talk to you. My question is regarding the real use for the space shuttle. If we're just using it to resupply the space station and any experiment that can be done on the space shuttle can be done on the space station, why don't we transfer the funds from the space shuttle, which is an aging technology, to something more efficient, to development and the experiments that can be carried out in space--have them carried out on the space station since that's what it's designed for anyway?

PALCA: Huh. OK. Interesting point, David. What about that, Frank Morring? Can--is there another way to get people up and down to the space station?

Mr. MORRING: Well, certainly, there is. As I mentioned, the Russian systems are--have been carrying the load for the past two and a half years. The problem is that the space station isn't completed and a lot of the modules and other parts that are going--that were built and have been built and have been delivered to Cape Ken--Cape Canaveral to be launched on the shuttle can only be launched on the shuttle. So NASA's problem is getting as much of that stuff up to the station as they can. A lot of it belongs to NASA's international partners, the European Space Agency, the Japanese space agency, and those people are going to be very unhappy if the billions of dollars that they've spent building their hardware doesn't get launched on the space shuttle. And, in fact, it's NASA's stated policy that they will launch as much of that stuff as they can.

PALCA: OK. David, thanks very much. I think we have time for one more call. Let's try Mary in Virginia.

Mary, welcome to SCIENCE FRIDAY.

MARY (Caller): Hi. I hope I'm coming through OK. I'm calling on my cell phone. My question is, I heard earlier in the interview where they were discussing with--the problem they had with the insulation coming off, that they thought they had fixed the problem and (technical difficulties) have an ulterior plan or did they have something set up in order to counteract the problem if it did happen?

PALCA: Yeah, I think I understand. Mary, I'm going to take the liberty of asking was--if there was as problem, was there a way to rescue the shuttle astronauts in an--was there a scenario for getting them back safely?

Mr. MORRING: There was. There's a space--another shuttle stacked up and almost ready to go down at the Cape right now. Unfortunately, it also has a tank on it. The idea was for the crew to stay on the space station until that shuttle could come up and rescue them. It's called the safe haven approach. They also have some experimental repair kits on the station, which they're going to be testing tomorrow morning, in fact, but no one really knows if that stuff works. And they probably wouldn't try to fly back on a repair made with that equipment.

PALCA: OK. Well, I think we're going to have to leave it there. Frank Morring, I know you'll be covering this. And, of course, NPR News will be covering it as events dictate. Frank Morring is the senior space technology editor for the publication Aviation Week and Space Technology. He joined us from Houston, where he's been following the space program.

We're going to take a short break, but when we come back, making memories that you can't remember. Sounds like a puzzle. Well, stay with us. We'll explain.

This is TALK OF THE NATION from NPR News.

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