IRA FLATOW, host:
You're listening to TALK OF THE NATION/SCIENCE FRIDAY. I'm Ira Flatow.
Who says that the only way to get into space is atop a rocket? If you're a science fiction fan, you might point to other, more futuristic methods, like the "Star Trek" transporter, which, as you know, is not quite a practical instrument yet; we can't actually get that going. Or you might say, `Hey! How about a space elevator, just like an elevator in a skyscraper?' Instead, you stretch a cable from the ground way up into orbit and it's anchored there, in orbit. You jump in a little car, climbs up the cable and it takes you into orbit. Huh? I think that's kind of neat. What do you think?
It sounds like a great idea, but would it work? Well, my next guest says it could happen, and happen within the next 15 years. Joining me now is Brad Edwards. He's the former director of research for the Institute for Scientific Research. That's a consortium exploring space-elevator technology. He's now the president of Carbon Designs Incorporated; that is a company looking into the ingredients that would go into building an elevator. He joins me by phone.
Welcome to SCIENCE FRIDAY.
Dr. BRAD EDWARDS (President, Carbon Designs Inc.): Oh, it's good to be here. Thanks for inviting me.
FLATOW: Did I describe it pretty well? Draw me a picture of what a space elevator might look like.
Dr. EDWARDS: Well, you did describe it pretty well. Really, it is a ribbon; in our scenario, about three feet wide, thin as paper. One end is attached to an anchor station, a floating platform in the Pacific. The other end is 62,000 miles up in space. And you attach a mechanical climber to it that pulls itself up the ribbon to space, drops off its payload at whatever Earth orbit or, if you let it go from the upper end, would throw payloads to the moon, Mars, asteroids. Basically, you don't need rockets anymore. It cuts the cost of getting into space dramatically.
FLATOW: And, you know, it doesn't violate any of the laws of physics we know about...
Dr. EDWARDS: No, no...
FLATOW: ...orbital mechanics or that kind of stuff?
Dr. EDWARDS: No. No, it actually uses it, because it's just like if you take a ball on a string and you spin it around your head.
Dr. EDWARDS: The string sticks straight out. It's the exact same thing we're talking about. The Earth is spinning. You've got this long string hanging outside. As the Earth spins, the upper half is thrown out, away from Earth, and it pulls upward. The bottom end is being pulled down by gravity, and it's actually stable and stationary.
FLATOW: Now how come that, if you go up on a cable car, let's say, that goes up your ribbon, you're not going to be pulling this thing out of orbit by the weight of that?
Dr. EDWARDS: Well, the climber that we're talking about weighs about 20 tons. It'll carry about 13-ton payloads. The ribbon--when we get done, the ribbon will weigh about 800 tons, and the counterweight, the ball at the end of the string, will weigh about 600 tons. So we do pull on it slightly, but not enough to move it. It's sort of like you can pull on a car all you want and put force on it, but the car doesn't move. It's the same thing that we're doing.
FLATOW: 1 (800) 989-8255; talking about the space elevator. Now you talked about the ribbon that would go back to Earth. This sounds very, very heavy. I guess the technology challenge to you is to find something that doesn't break.
Dr. EDWARDS: That's right. It's--the concept's been around for many years. It's actually been in science fiction, largely. The reason it's been in science fiction is because there's been no material strong enough to make it. That changed in 1991 with the discovery of carbon nanotubes, and now, with the ramp-up in production and manufacturing, development of them, the carbon nanotubes have been measured at strengths that are more than sufficient to make the space elevator. So that's what we're working on now, is to get those materials into a form that we can use to make that ribbon.
FLATOW: Mm-hmm. 1 (800) 989-8255. Let's go to the phones. Let's go to Justin in Kansas City. Hi, Justin.
JUSTIN (Caller): Hi. How are you doing?
JUSTIN: I think the guest already alluded to my question. I remember reading this in a children's series, "A Wrinkle in Time," I believe, and I was just kind of wondering where the idea came from, but I guess you already...
Dr. EDWARDS: Well, the original idea for this space elevator goes--you know, you can sort of go back as far as you like to the Tower of Babel or, you know, any number of scenarios. But Tsiolkovsky back in 1895 sort of first talked about a tower beyond geosynchronous, Artsutanov, a Russian, proposed the first modern version about 1960. Arthur C. Clarke and a few others have added in novels over the last 40 years. That's pretty much where it's sort of evolved from.
FLATOW: So what breakthrough do you need? Do you need to actually invent the cable, or the ribbon, as you call it, that's strong enough to do this?
Dr. EDWARDS: Well, we don't really have to invent it. The material is--as I said, the carbon nanotubes actually are existing at strengths we need, and what we need to do is develop them into a composite material or a spun material that has those characteristics in a larger material. And that's--the basic concept is not--is fairly straightforward. It's just a matter of implementing it. And that's the real last technology. We still have engineering studies. We still have, you know, optimizing designs and things like that, but those are all things you have to do with any large project.
FLATOW: Is there a business here? Is this a private project, much like the space plane was?
Dr. EDWARDS: Well, right now the space elevator--up until a couple of years ago, very, very few people knew about it. And so it's really just getting started. There's a couple hundred researchers now that have sort of taken up the torch and are working on it at a number of locations, including Los Alamos National Laboratory, some private companies, some people at MIT, various locations. And right now, there's not a dramatic amount of funding for it, and that's part of what we're working on is to get...
Dr. EDWARDS: ...funding to do it, from private sources, from commercial sources. But since it's new, it always takes a bit of time to be accepted.
FLATOW: Right. How...
Dr. EDWARDS: Usually people look at first thing they think is it's crazy.
FLATOW: That didn't stop a lot of people from making what they said they would.
Dr. EDWARDS: Yeah.
FLATOW: How long would it take--if you're on the ground and you put something on the elevator--and how high an orbit is it? And how long would it take to get there, to sort of climb your way up?
Dr. EDWARDS: Well, climbing up to get up to essentially the height of the Space Station...
Dr. EDWARDS: ...would take a few hours. And then if you want to go up to the height of geosynchronous satellite, a telecommunications satellite which 22,000 miles up, that's like, you know, driving all the way around the Earth. That'd take about eight days.
FLATOW: That's not so long.
Dr. EDWARDS: To get to the moon or Mars, you'd go up a bit farther, and then you would be released onto an orbit or trajectory, and actually, the elevator can throw you fast enough that you can get to those locations in much less time than the rocket.
FLATOW: You mean you could sort of use this as a yo-yo sort of thing? You could, like, fling yourself up the elevator and then let go on the end and then into interplanetary space?
Dr. EDWARDS: It's just like a sling. If you think about the ball on a string again, spinning around your head...
Dr. EDWARDS: ...you let go of it, that ball on a string goes flying across the room. In the same way, if you were to slide something up that string and it goes off the end of it, it would go across the room, in the space elevator, you go up to the upper end or the upper half and you let go at the right time, it'll throw you to the moon or throw you to Mars or throw you to the asteroids at very high rates of speed.
FLATOW: Wow. 1 (800) 989-8255. Let's go to Patrick in Portland. Hi, Patrick.
PATRICK (Caller): I was wondering, what keeps the ribbon from attracting or generating lightning?
Dr. EDWARDS: Well, actually, where we're going to be locating this is this nice location, eastern equatorial Pacific, straight down from California, right on the equator. In that area, it's about a thousand kilometers by about 4,000 kilometers; it has no lightning, which is very unique.
PATRICK: It does not generate or would not make the conditions right to attract lightning, then? It would not become a giant lightning rod, would be my question?
Dr. EDWARDS: Well, there is a question on whether it would and whether it would generate the lightning there. It appears that it won't. If it does start generating electricity, there are a couple of options. We can use, for example, a Kevlar leader for the last couple miles, which would not be conducting. The carbon nanotube composite ribbons themselves should not be conducting, either, so it's not a metal lightning rod. So in general, it should not be conducting, unless we really sort of screw up in the design of that ribbon.
PATRICK: Well, thanks for...
FLATOW: Yeah. You don't want to do that.
Dr. EDWARDS: Yeah.
FLATOW: All right, Patrick. Thanks for calling.
FLATOW: So give us your timetable. Let's say in the best possible world, if everything comes true and you get your funding and whatever, how soon before we see that first cable in space?
Dr. EDWARDS: Well, with good funding, we should have the development done in the next couple years, and then at that point we would be doing sort of the full design and construction, and it would take about another 10 years. If you talk about regulations, regulatory issues that are going to delay us a few years, we're talking about 15 years. Now in reality, of course, it doesn't go perfectly, so it may be a little bit longer than that. But even if we could get this up in 15 years--as of about six years ago, it was 300 years to never. So I think we're doing pretty good on the 15.
FLATOW: Now NASA has this thing called the Centennial Challenge, where it's trying to develop new space technologies from entrepreneurs like yourself. Are you involved in that at all?
Dr. EDWARDS: Actually, yes, to an extent. There's an organization, Spaceward organization in Mountain View, California, that's organizing a climber competition, and they have been announced as the first Centennial Challenge. There is about $400,000 in prizes for the next two years for a climber challenge, which is actually officially termed as a power beaming challenge, and the Tether Challenge, to develop the high-strength material. So the Centennial Challenge has actually, you know, stepped up and said, `Yes, this is important,' and has basically assigned that competition as the first one in their challenge.
FLATOW: Mm-hmm. 1 (800) 989-8255. Curt in Salt Lake City, hi. Welcome to SCIENCE FRIDAY.
CURT (Caller): Hi.
FLATOW: Hi there.
CURT: I had sort of a two-part question. One: I'm trying to understand how you deal with the forces generated by high-altitude winds and how they would keep this ribbon from creating a large bow as it goes up into space. And then also, it would seem to me--and I'm not a rocket scientist, but--that orbital mechanics get kind of goofy up there, and if you try to tie this station still up in space, it's going to rotate and pop around and end up snapping this ribbon. I was wondering how you dealt with those problems.
Dr. EDWARDS: Well, for the high-altitude winds, if you look at the equator, first, the hurricanes, for example, do not go into that area, but those are the low-altitude. The high-altitude winds--for example, jet streams--are not present at the equator. Now there are some high-altitude winds up about 18 kilometers altitude that go up to a couple hundred miles per hour; however, if you look at those, the density of the atmosphere is down such that the total force on the ribbon is similar to a 20-mile-an-hour wind here on Earth. And we've gone through the calculations on how much that would move it, and we believe that we're still in pretty good shape with those.
On the upper end, the things that will start to move the counterweight in the upper end of the ribbon will be things like the moon. When it goes by, there'll be a slight gravitational tug on it. When it goes past the sun, there'll be another slight gravitational tug. Those are in about 24-hour periods. The natural period of our ribbon is about seven hours. So there's not a good connection there. If we start to get some movement--and, again, it'll be a seven-hour type of period--we can correct some of that from the base station. We can start moving the ribbon at the base to counteract some of those movements.
FLATOW: All right, Curt?
CURT: Thank you.
FLATOW: Thanks for calling. 1 (800) 989-8255. Nancy in Salisbury, North Carolina. Hi, Nancy.
NANCY (Caller): Hi. Thanks for taking my call. My question is what would keep domestic airlines, earthbound airlines, airplanes, from flying into this thing?
Dr. EDWARDS: Well, hopefully, they'll actually try to avoid it, but the other aspect of it is where we're located is about 400 miles from any air routes or sea lanes. We're really sort of out in the middle of nowhere. We selected it for the weather, but it does stay out of the way of most of the airplanes. Someone really has to be off route by about 400 miles to come and hit us.
FLATOW: So you'd have to...
NANCY: That would--I'm sorry.
FLATOW: I'm sorry, Nancy. You go ahead.
NANCY: That would bring up another point. If something did fly into it, what--I'm sure you might have taken into consideration what the results of that would be? I mean, not only for the airline or the thing that flew into it, but for the ribbon itself.
Dr. EDWARDS: Yes. If an airline were to hit this ribbon, what would probably happen is it would probably severely damage the airline, the aircraft, and the ribbon...
Dr. EDWARDS: And the ribbon itself. It's conceivable that we would lose the ribbon. What would happen is a piece of ribbon below that point would fall to the ground. At least above that would essentially be pulled up and out of its orbit to a large extent. There may be some parts of it that may fall back down, burn up kind of thing in the atmosphere, similar to rockets re-entering. But most of it would actually leave its orbit. It would be a financial loss, whatever.
FLATOW: We're talking about an elevator to space this hour on TALK OF THE NATION/SCIENCE FRIDAY from NPR News. Talking with Brad Edwards, who is now president of Carbon Designs Incorporated.
What about the little cab or the elevator itself riding up there. What would that look like? Would it look like a normal little car? You know, like a box riding in an elevator and pull itself up by a motor up the ribbon?
Dr. EDWARDS: Well, the designs that we got--they're not real pretty; they're pretty much functional. It's got sort of an open truss-type frame, and it will have a large solar ray to collect energy from the laser power beaming that we'll use, and it'll have a drive system, a set of rollers, motors, and then it'll have a few electronics boxes. So the first one--there's--the climber itself doesn't look real fancy, doesn't look like a Buck Rogers kind of thing. Now if you're taking up cargo or passengers or anything like that, that would be an attachment to this climber, the payload. If you're taking up people, yes, it'd probably be a spherical cylindrical, windows obviously required kind of system.
So it would look--it--probably still pretty function, not real sleek, you know, streamlined, anything like that, because none of that's actually needed for the elevator. It would move real slow through the atmosphere; no resistance or anything else once you get up into space.
FLATOW: If it's anchored in a certain place by the equator, can--what do you do once you get something into orbit? How do you move it around? Let's say you wanted to supply something like the space station with cargo.
Dr. EDWARDS: Well, for the space station--actually, in the elevator, going to lower-Earth orbit's more difficult for us than going to geosynchronous orbit. If you go to geosynchronous, you go up to 22,000 miles and you then let go of the ribbon, and you are in orbit. You want to move to a different position in that orbit, you can release a small amount of gas and move to a different location. If you want to go to lower-Earth orbit, you actually go up above lower-Earth orbit and then drop the payload down. You'll go into an elliptical orbit, and then it'll be caught by the station or maneuver itself to meet up with the station.
You may need some small rockets to change the plane a little bit, change the orbital direction. So you may need nothing the size of the rockets that we currently use to get them from Earth into space, though. It's a much, much smaller requirement.
FLATOW: We're going to take a short break and come back and move on to another subject. So I want to thank Dr. Brad Edwards, president of Carbon Designs Incorporated based in Dallas, Texas.
Thanks for talking about your space elevator
Dr. EDWARDS: Yeah. You're welcome.
FLATOW: ...with us this hour.
As I say, we're going to take a short break and come back and talk about how you search for something, how your brain is involved. You know how you'll stare at something and you think you see it? You're looking for something, you can't find it? Well, our next guest is going to talk about how your brain is operating there, what may make it easier for you to find something, you know, hidden in plain sight. So stay with us. We'll be right back after this short break.
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FLATOW: I'm Ira Flatow. This is TALK OF THE NATION/SCIENCE FRIDAY from NPR News.
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