RENEE MONTAGNE, host:
At this hour, final preparations are underway for the launch of Atlantis, the last American shuttle to venture into space.
STEVE INSKEEP, host:
Hundreds of thousands of spectators will be on hand in Central Florida to watch the final shuttle launch if the weather permits that launch. We're going to talk about that and more with NPR's science correspondent Joe Palca, who's in our studios here in Washington. Joe, good morning.
JOE PALCA: Morning.
MONTAGNE: Morning to you, Joe. And what will determine if the launch can happen?
PALCA: Well, right now they're saying that there are no technical problems and the fuel has been loaded into the fuel tank and so now everybody's just looking at the weather.
INSKEEP: OK. That weather has not looked very promising from what we've heard over the last 24 hours.
PALCA: No. There's a number of things that have to go right before the shuttle can actually take off in terms of its weather criteria. One is you can't have any rain, because raindrops can actually damage the heat tiles because the shuttle is moving so fast when it's taking off...
INSKEEP: It's not the speed of the raindrop, it's the speed of the shuttle.
PALCA: It's the shuttle banging into those raindrops at such a high speed, yeah.
INSKEEP: That's amazing that it could destroy those tiles that are incredibly strong but not that strong, I suppose.
PALCA: Well, they were made for heat, not for rain.
INSKEEP: So, that's one criterion.
PALCA: Right. The others are that, I mean, they have criteria for temperature: can't be too cold - that's not going to be an issue - can't be too windy -that's not going to be an issue. But the other issue is that they have to be able to - they don't want lightning. So, if there's lightning in the area or even if there are clouds that could produce lightning, they don't want to fly into those.
So, those are the things that the weather forecasters are going to be looking at. There's one other thing that gets a little more complicated still because not only does the weather have to be good at the Kennedy Space Center, it has to be good at the abort landing sites, which are in Spain and southern France, in case there's a problem in takeoff and they have to land as they cross the Atlantic. And they have to be good at the other landing sites - at Edwards Air Force Base in California and White Sands, New Mexico.
So, a lot of weather has to line up properly for them to launch.
MONTAGNE: But, Joe, if there is in fact a break in the clouds and there's the chances, the odds aren't that good for that, what? The shuttle could launch.
PALCA: Yeah, that's right. I mean, they say there's a 70 percent chance of weather scrubbing the flight. But that means that there's a 30 percent chance that there won't be a problem and they don't need a huge gap in the weather -they need 10- or 15-minute gap in the weather where they're certain that they can get through the clouds and through the rain or avoid the rain in this circumstance.
INSKEEP: OK. So, just so we're clear what's happening right now we're actually watching the NASA TV feed here. We're seeing all lit up in the night in Florida the shuttle Atlantis along with the giant fuel tanks and the rockets there. They're on the pad. So, what looks like steam coming off of it, which I guess is normal at this point.
PALCA: I think it's venting some fuel, but yeah.
INSKEEP: OK. And so what's happening? The astronauts must have been waken up at this point. Are they on board?
PALCA: They're up. They're not on board there. They just had their final physical exams and they're going to be making their way to the pad. I think they get there around 8 o'clock this morning.
INSKEEP: OK. So, we'll find out a little later in the morning if the weather is deemed sufficient in all those places to actually launch. But I have a question as we wait, Joe Palca, because I know you're somebody who's been trying to cover the next phase of space travel, whatever it might be. What is this moment, the final shuttle launch, feel like to you, Joe?
PALCA: Well, it does have this end of an era quality to it, which I certainly accept. But I think even ever since the space station - that's why the shuttle exists essentially, was to create the space station - but the space station, it's built. But if I asked you what are the 10-most important things we've learned from having an international space station, I'm sure you'd have a hard time coming up with a list because we've learned about how humans live in space but not the kind of scientific bounty that some people were predicting.
So, I think what this is saying is everybody has a sort of feeling, what are we going to do next? The space station's there, it's working, it's going to be around for a while, but is there something else?
INSKEEP: What is the next frontier? People don't really know.
PALCA: Well, at the moment, nobody's made a commitment to any particular one, no.
INSKEEP: Even in the private sector, where a lot of interesting things are happening, a lot of interesting plans are being talked about, there's nothing very impressive scientifically?
PALCA: Well, there's going to be space tourism - that's going to be interesting. There could be space hotels. But, you know, is that the direction the country wants to go? I don't know.
INSKEEP: OK. NPR's Joe Palca will be with us throughout the morning along with our crew in Florida, Texas and elsewhere as we await news to see if the shuttle Atlantis goes off the final shuttle flight. Transcript provided by NPR, Copyright NPR.