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AP: Sounds like an interesting board. I've always been fascinated by science and I've been a SF buff since I was an adolescent (the melding of fiction and future science, I guess). Over the last few years, I've taken a stab at writing SF myself. My second novel is largely centered around a space elevator (a topic that has nearly reached the point of progressing from SF into science fact).

Space elevators are interesting for a number of reasons:

1) They offer a cheap way to move cargo between Earth and orbit--once you get past the large initial start-up costs. (No rockets, just frictionless elevator cars traveling up/down a carbon nanotube ribbon cable.)

2) The far end of the elevator would be a space station in geostationary orbit, which could function as a depot for handling people and things in transit up/down the elevator, as well as a low-gee/zero-gee research and manufacturing facility and as an "air traffic controller" for ships in or near orbit.

3) Because the elevator/station functions like a ball swung around a person's head on the end of a string, the cable actually holds it down, rather than up. (Centrifugal force would cause the station to be hurled into space if the cable broke.) As a result, any ships docked to the station would be subject to the same centrifugal force as the station itself. By simply undocking from the station, the ship would be hurled away from Earth by that centrifugal force, getting a free boost toward its destination (assuming the undocking was timed correctly). How much of a boost? Using a 78,000 km cable between Earth and the station, the boost would be on the order of 20,000 kph! (I verified these calculations with the acknowledged expert on the subject, Dr. Brad Edwards, who wrote the NASA-sponsored proposal on the subject.)

Pretty impressive stuff! This "slingshot" approach also offers the potential for unpowered/uncrewed "space trains". These would be cargo containers hurled by centrifugal force between Earth and, say, Mars, where they would be captured by space tugs and towed to another space elevator for lowering to the planet's surface. Then Mars could in turn hurl cargo (refined ores, perhaps) back to Earth.

I talk about a lot of this stuff in my novel. It's called "Lichen or Not". (Still looking for a publisher.)

Here's a link to Dr. Edwards' study, for anyone interested in reading about space elevators. (I disagree with some of his conclusions, however, such as having floating "anchors" for the tethers to attach to. He suggests moving them around to keep the tethers out of the way of orbiting debris, which I think is impractical. Just how much could you move a floating platform the size of a drilling rig on a daily basis? Not only that, but to make the elevator commercially viable, you'd need a large shipping infrastructure around it--wharfs, warehouses, etc.--which would be impractical with a base that constantly moves around.)

http://www.spaceelevator.com/docs/521Edwards.pdf

The advantage I have over Dr. Edwards is that my novel is set 170 years from now, so I've had time to work out all the bugs in the system.... <grin>, such as including Gravitic Field Generators on the space stations, so that everyone has a nice 1G gravity to work in, and using superconductor-powered maglev elevator cars, instead of the laser-powered cars he envisions (with the lasers on Earth, firing at the underside of the cars as they rise through and beyond the atmosphere, in all weather conditions--sounds unrealistic to me).

Anyone, if anyone wants to discuss space elevators/trains, I think that would be an interesting topic.

Mark.
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Dear Mark

I really enjoyed reading your post on space elevators - you've obviously considered the technological details in some depth.

I think I first came across the idea of a space elevator in Arthur C. Clarke's novel "The Fountains Of Paradise". From what I remember, it seems like the major problem is finding a material that won't sag under its own weight when you make it into a cable that's thousands of miles long.

I guess that carbon nanotubes weren't even on the horizon when Clarke wrote the novel in 1978. The space elevator is a good example of something that might have been labelled (forgive the pun) a "pie in the sky" idea in its day because some vital piece of supporting technology that could have made it feasible (in this case, related to the material science) simply did not exist. But it's a testament to Clarke's vision that this idea has survived and continues to be considered.

Best

Gordon
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this idea has survived and continues to be considered.

Ah, but what entity will have the guts/money/where-with-all to try and build one? And where would they put it? What government is going to let a company put it on their soil? What other governments are going to scream about "what happens if it falls down on top of us?" Not to mention the envirnomental extremists that already worry about radiation from satellites/probes exploding on launch!

And if a government wants to do build it itself to retain control, just what agency will do it? The US would have to make a new one (oh the bureaucracy!) because putting it under NASA's purview is probably a bad idea.

Or should we stick to science and not bother with the political/socio-economical ramifications?

RM

PS to Mark, does your novel cover any of this or is more of a pure techie novel? I like both kinds myself.

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Y'all are a little behind on space eleveators. NASA has been taking a two-track approach so far:
- NIAC-type studies; as previously indicated;
- most recently, breaking up the job into small 'pieces' and offering prize competitions for each small increment additional. Prizes are currently limited by law; but it's been increased once already, and the agency is working on an additional increase. The only small competition staged so far created an incredible amount of media interest--totally out of proportion to the exceedingly small effort at the moment; got on CNN, the major wires, etc.

Right now, NASA has opened the doors to any recommendations on what new, specific prizes might be offered in the space- breakout category of things, or change of direction in them, etc. etc. Go to nasa.gov and look for Centenial Prizes.

One other thing: congrats on the superconductor angle; we're closer to that (IMO) than you might think. Japan's 70-km superconductor maglev train test track has always been regular superconductors; but last year, for the first time, they got into high-temperature superoconductor testing, with HTS wire from American Superconductor in Massachusets. (AMSC is now producing over 400,000 meters/year of either first generation or second generation wire). You can drop by our (occassionally-used) AMSC board.

jp
FD: own AMSC
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>>>>I think I first came across the idea of a space elevator in Arthur C. Clarke's novel "The Fountains Of Paradise". From what I remember, it seems like the major problem is finding a material that won't sag under its own weight when you make it into a cable that's thousands of miles long.

Gordon: Actually, the problem is just the reverse. A space elevator doesn't have to be stron enough to support it's own weight. It has to be strong enough to keep the "string" from snapping and hurling the counterweight (space station) off into space. The only part than can fall is the carbon nanotube tether cable(s). And because it's made of carbon, most of it will burn up in reentry. Because it would only have to be microns thick, it would be like a multi-thousand-mile long roll of toilet paper falling (unrolled), rather than some huge steel structure.

As for Clarke, yes, he and Charles Sheffield wrote novels with similar concepts the same year. But they weren't the first to com eup with the idea by a long shot. Here is my afterword from the novel:

The space elevator described in this novel may not be in the realm of science fiction much longer. “Celestial towers,” “beanstalks,” “sky hooks,” and others similar concepts have been discussed and refined for decades: from Konstantin Tsiolkovsky in 1895 though Yuri Artsutanov in 1960, Jerome Pearson in the mid-1970s, Sir Arthur C. Clarke's novel The Fountains of Paradise and Dr. Charles Sheffield's The Web Between the Worlds in 1979, Kim Stanley Robinson's Red Mars/Green Mars/Blue Mars trilogy in the '90s, and a study commissioned by the NASA Institute for Advanced Concepts (NIAC) and authored by Dr. Bradley Edwards in 2000-2002 . Various possible solutions to some obstacles have been proposed along the way, but others required future science to provide the answers.

Until recently, the biggest obstacle was finding a material that was far stronger and yet lighter than steel, to use as the cable material. Kevlar was the first step in this direction, yet it too fell well short of the necessary strength-to-weight ratio.

Finally, in 1991 electron microscopist Sumio Iijima discovered carbon nanotubes (CNTs). CNTs offered the strength-to-weight ratio necessary to make space elevators a practical consideration.

The largest remaining technical hurdles appear to be finding ways to produce mass quantities of carbon nanotubes and link them together into cables tens of thousands of kilometers long, and how to keep all the space junk orbiting Earth from colliding with the elevator. Beyond that is the larger issue of finding the funding and the will to undertake a task that would make the International Space Station program pale by comparison. Still, the NIAC study suggests that a feasible design could be constructed within the next fifty years. By the late twenty-second century, when this novel is set, the technical, financial, and sociological hurdles should have been resolved.

Many of the space elevator concepts used in this story come from the authors cited. Any errors in interpretation or extrapolation are mine.


Mark.
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>>>>Ah, but what entity will have the guts/money/where-with-all to try and build one? And where would they put it? What government is going to let a company put it on their soil? What other governments are going to scream about "what happens if it falls down on top of us?" Not to mention the envirnomental extremists that already worry about radiation from satellites/probes exploding on launch!

RM: It'll take an international effort, combining government and industry to make space elevators feasible (especially as we'll need several of them over time to serve the needs of the entire planet.) Where to put them? They'll have to be along the equator. This means there is plenty of open ocean in which to anchor them, preferably along the continental plates (so the sea floor isn't too deep and the elevators are near ports where the cargo can be imported/exported through). (In my novel, I have five of them: one each on either side of S. America (NE of Brazil and near the Galapagos Islands), to serve the western hemisphere, one off the west coast of Africa (Gabon) to serve Western Europe and Africa, one in the Indian Ocean (Maldives) to serve Eastern Europe, the middle East and cental Asia, and one near Papua New Guinea to serve eastern Asia/Australia.

To truly be feasible, the orbital platform would need more than one elevator tether connecting it to Earth. Even traveling at an average of 1,600 kps (which should be achievable by a maglev train in vacuum most of the way), it would take two days each way to traverse 78,000 km. A four-day turnaround just wouldn't be financially viable if there were large loads of cargo to go each way. But having, say, 24 tethers, with six elevator cars per tether, would provide 144 total cars. half could be ascending while the other half are descending. That's 72 cars per day in each direction, or three per hour. Now we're talking plane/train-like schedules. (Of course, we couldn't do anything like this initially. It might take a century or more to build up to this.)

There will always be environmental extremists, so all you can do is try to work around their concerns. But there's no reason this project should be any more of a concern than building a new airport offshore (like they did in Japan) or other large structure. As most of the structure will be in the air and in space, there could actually be less impact on the surface than a larger structure (like an airport) would have.

>>>>PS to Mark, does your novel cover any of this or is more of a pure techie novel? I like both kinds myself.

The space elevator is a tool, like space ships. So, while I describe how it all works enough that the reader is "on the same page" as me, I don't go into a lot of social ramifications of the building/operation of the elevator itself. There is some sabotage that occurs, but it's not due to political/eco extremism. (I don't want to give away the surprise, in case anyone here reads the book.) This is my second novel, although a prequel to my first. I have an idea for a prequel-prequel set decades earlier, so I might delve into more of that in the later book. (I'm currently working on the third book in the series, with an idea for another book to go between #2 and #3. There's no telling where it all might lead.) Presently, the first two books are 99% independent of one another. (There is one minor character introduced at the end of the first book that becomes the protagonist of the second. I pull both books together in the third one.)

If you or anyone else here is interested in reading it, just send me an e-mail, so I have your return e-mail address. I'll send you a PDF file. The book has been through four drafts so far, so it's in pretty good shape, but I'm always happy to get more feedback so I can improve it. (I'm currently drafting a query letter prior to submitting the ms to agents.) There's a lot of "techie" stuff in the books, for those who like "hard" SF, but the stories are really about the people. In the case of the first book (Lichen or Not), it's a coming-of-age story about a young man setting out on his first job, as a Martian geologist (areologist). Life is never simple on the frontier....

Mark.
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>>>>One other thing: congrats on the superconductor angle; we're closer to that (IMO) than you might think. Japan's 70-km superconductor maglev train test track has always been regular superconductors; but last year, for the first time, they got into high-temperature superoconductor testing, with HTS wire from American Superconductor in Massachusets.

JP: That's good news. I hadn't heard. My story is set ~170 years in the future, so that allowed me to declare that all these mundane "picks and shovels" types of problems have long since been overcome. Here's how I describe the basics of the space elevator. (Each chapter of the book begins with a fictional encyclopedia entry about some aspect of what happens in that chapter.)

Chapter 1.
Engineering Marvels: Space Elevator
– A space elevator consists of three sections: 1) A GEOSTATIONARY space station, called an ORBITAL DOCKING FACILITY (ODF); 2) A base platform, which serves to anchor the ODF on or near the equator of Earth or another planet; and 3) Multiple ribbon cables and elevator cars connecting the two. Each cable is formed from a high-tensile composite consisting primarily of dozens of micron-thick bonded layers of MULTIWALLED CARBON NANOTUBES (CNTs). CNTs have a strength-to-weight ratio hundreds of times superior to that of steel. Elevator cars operating on the principles of MAGNETIC LEVITATION (MAGLEV) ride along these cables at high rates of speed.
-- Excerpt from Encyclopedia Solaris, 2176.

Chapter 2.
Engineering Marvels: Space Elevator
– Up to six MAGNETIC LEVITATION (MAGLEV) elevator cars travel up and down each ribbon cable, transporting both passengers and cargo. The cars differ in many ways from traditional land-based maglev trains. Rather than riding atop a narrow horizontal rail, the elevator car is suspended alongside a vertical flat ribbon cable. The ribbon passes between two sets of magnets, on the front and back sides of the cable. This arrangement prevents the train from drifting away from the ribbon. An elevator car has to travel tens of thousands of kilometers nonstop. Therefore, it is impractical for an elevator car to be self-powered. Instead, the motive force is provided by the ribbon cable.

The cables could not be made of copper for several reasons: 1) copper is far too bulky and heavy, 2) it was in short supply, and 3) too much power would dissipate along the way. Some sort of lightweight superconductor was required. The cable is composed primarily of MULTIWALLED CARBON NANOTUBES (CNTs), reinforced with BORON NITRIDE NANOTUBES. However, the outer courses of the ribbon, front and back, also contain a thin layer of HIGH-Tc superconducting material. These layers act as power conduits, reaching all the way from the ground platform to the ORBITAL DOCKING FACILITY. Woven transversely across the ribbon, in strips, are threads made of superconducting magnets that tap into the power source. As a result, the elevator cars need only enough internal power to maintain the onboard magnets and life support. The cable itself provides the motive force.

The strips are pulsed in series, like theater marquee lights that chase themselves in a loop. Strips in front of the car magnetically draw the car forward, while others push the car from behind. Then, as the car approaches its destination, the pulses reverse themselves to slow the car for docking.
-- Excerpt from Encyclopedia Solaris, 2176.


(Note: The part about High Tc superconducting materials came from Dr. Edwards.)

What I like about formatting the story this way is that those people who like hard SF can read the technical descriptions at the beginning of each chapter. Those who prefer soft SF can skip over the "boring details". This way it doesn't bog down the story with a lot of exposition in the middle of chapters.

Mark.
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It occurred to me that after seeing the "encyclopedia entries" you folks might get the wrong impression of the writing style of the novel. Those parts are supposed to sound dry and technical. But the rest of the novel is much more relaxed. Here is the (short) opening scene:

*************************************************************************
“Crap, crap, CRAP!

He clenched his teeth and watched the aftershave roll across the floor.

This was the final straw, the ultimate thread in a richly-woven tapestry of frustration. It was as if the gods of travel had decreed that nothing would go right for Jamie McKie this day. Born of extreme exasperation, a grunt like that of a strangled moose caused other travelers in the terminal to cast puzzled glances his way.

McKie's day had started out well enough, with a pleasant family breakfast. His mom made waffles while Jamie and his dad swapped jokes.

After the final morsel was used to mop up the last swirl of maple syrup, it was time to leave.

“You make sure you keep warm, Jamie. It's awfully cold out there.” Jessica's deep blue eyes peered into her son's hazel ones. She fought back tears.

“Yes, Mom.” McKie made an effort not to roll his eyes as he spoke. “I think I know how to dress myself by now....” His smirk made Jessica smile and sniffle.

“The taxi's on its way, son,” Talmadge said, stepping away from the phone. “In the meantime, I think your friends want to say good-bye.” He nodded in the direction of the front door.

McKie tucked a wayward lock of sandy hair under his stocking cap and yanked on his coat. His duffel bag was already waiting for him by the door.

He turned to his mother and gave her a big bear hug, then he stepped back and shook hands with his father. Jessica dabbed at her eyes with the dishtowel draped over her shoulder.

“We'll miss you, son,” Talmadge said.

Jessica nodded, silently.

“I'll miss you, too -- both of you. But I can't turn down an opportunity like this.”

“We know, Jamie. But almost three years. That's such a long time.”

McKie shrugged. What else could he say? He turned and picked up his bag. As he held open the door to leave, he turned back. “Bye, Mom, bye, Dad. I'll be back as soon as I can. I love you.”

Jessica's eyes overflowed at last. Talmadge spoke for both of them. “We love you, too, son.”

McKie waggled his fingers in a half-wave and slipped through the door, closing it firmly behind him.

Outside by the curb, his friends were awaiting their turn to say good-bye. Mary-Anne Sevinski and Dave Plowright were his oldest friends. The trio had been together since grade school. McKie trudged through the fresh knee-deep snow on the walk until he reached his friends.

“I can't believe you're leaving like this,” Dave said. “We've always been here for each other. Now you're running off and leaving us.”

“Don't be so melodramatic,” Mary-Anne scolded. “He's just taking a job. You'd do the same, given the opportunity.”

“Well, maybe. But I'm not the one who's leaving.”

“That's only because you have a job waiting for you at your dad's company,” McKie said. “We don't all have that luxury.”

Dave shrugged. “Still, I hate that you're going.”

“Me too,” said Mary-Anne. Now her eyes were beginning to mist over.

McKie shrugged. “I'll be home before you know it.”

“Yeah. Sure.” Dave looked like his best friend had just died. It wasn't quite that bad, but for the next few years his best friend would not only be out of town, but millions of kilometers away. That wasn't much better than being dead.

From that point on, the good-byes devolved into a teary affair involving much hugging and back-slapping. Eventually, the taxi arrived to take McKie to the airport.

That's when things started to go wrong.
*********************************************************************

Mark.
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but millions of kilometers away.

Thank you SO much for not using klicks. That just drives me nuts! ;-)

Nicely written, your dialog is not stilted (I can't write dialog for anything!). And thus far your descriptions don't sound like travelogues.

I have one hope too, that no where in your novel do you ever, EVER use the phrase: He/she/it "drank deeply". Damn, I HATE that phrase!

RM ;-)
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>>>>Thank you SO much for not using klicks. That just drives me nuts! ;-)

RM: You're welcome. The omniscient narrator never uses the short form, but a couple of characters use that term a few times. (The characters speak for themselves. They never listen to what I tell them.)

>>>>Nicely written, your dialog is not stilted (I can't write dialog for anything!). And thus far your descriptions don't sound like travelogues.

I'm glad you think so. I do lapse into semi-eloquence from time to time:

They passed through the elevator terminal and out into the ODF reception area. When they turned a corner they were faced with a spectacular view of Earth, seen through a wall-length window. The entire western hemisphere was laid out before them: lightning flashed over northern Mexico; clouds obscured Cuba and northern Canada; the snowcapped Andes gleamed in the late afternoon sun. Skinning the curve of the Earth, a thin blue rind revealed the dimensions of the atmosphere. McKie stood there speechless for a solid minute before shaking himself out of his reverie.

and:

Despite McKie's eagerness to finish, he took a few moments to admire the view through his helmet. Other than the ridge at his back, and some low hills in the distance, there really wasn't much to look at. No grass, no flowers, no trees, no animals, no birds, not even some desiccated sagebrush tumbling across the barren plain. It almost could have been a rocky wasteland anywhere on Earth; but it held a stark beauty nonetheless. The sky was indigo above, with little lingering dust in the atmosphere to refract the sun's rays and tint it rose. Everywhere he looked, the hills, rocks, and plains were rust red, gray or brown.

>>>>I have one hope too, that no where in your novel do you ever, EVER use the phrase: He/she/it "drank deeply". Damn, I HATE that phrase!

No, I try to avoid saying "he/she/it".... 8^} (Just kidding.) No, I don't believe I've ever used the phrase "drank deeply" in any context.

Mark.
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