Scientist Sees Space Elevator in 15 Years

Science - AP ^ | 2004-06-25 | CARL HARTMAN

[Junior]

WASHINGTON - President Bush (news - web sites) wants to return to the moon and put a man on Mars. But scientist Bradley C. Edwards has an idea that's really out of this world: an elevator that climbs 62,000 miles into space.

Edwards thinks an initial version could be operating in 15 years, a year earlier than Bush's 2020 timetable for a return to the moon. He pegs the cost at $10 billion, a pittance compared with other space endeavors.

"It's not new physics — nothing new has to be discovered, nothing new has to be invented from scratch," he says. "If there are delays in budget or delays in whatever, it could stretch, but 15 years is a realistic estimate for when we could have one up."

Edwards is not just some guy with an idea. He's head of the space elevator project at the Institute for Scientific Research in Fairmont, W.Va. NASA (news - web sites) already has given it more than $500,000 to study the idea, and Congress has earmarked $2.5 million more.

"A lot of people at NASA are excited about the idea," said Robert Casanova, director of the NASA Institute of Advanced Concepts in Atlanta.

Edwards believes a space elevator offers a cheaper, safer form of space travel that eventually could be used to carry explorers to the planets.

Edwards' elevator would climb on a cable made of nanotubes — tiny bundles of carbon atoms many times stronger than steel. The cable would be about three feet wide and thinner than a piece of paper, but capable of supporting a payload up to 13 tons.

The cable would be attached to a platform on the equator, off the Pacific coast of South America where winds are calm, weather is good and commercial airplane flights are few. The platform would be mobile so the cable could be moved to get out of the path of orbiting satellites.

David Brin, a science-fiction writer who formerly taught physics at San Diego State University, believes the concept is solid but doubts such an elevator could be operating by 2019.

"I have no doubt that our great-grandchildren will routinely use space elevators," he said. "But it will take another generation to gather the technologies needed."

Edwards' institute is holding a third annual conference on space elevators in Washington starting Monday. A keynote speaker at the three-day meeting will be John Mankins, NASA's manager of human and robotics technology. Organizers say it will discuss technical challenges and solutions and the economic feasibility of the elevator proposal.

The space elevator is not a new idea. A Russian scientist, Konstantin Tsiolkovsky, envisioned it a century ago. And Arthur C. Clarke's novel "The Foundations of Paradise," published in 1979, talks of a space elevator 24,000 miles high, and permanent colonies on the moon, Mercury and Mars.

The difference now, Edwards said, is "we have a material that we can use to actually build it."

He envisions launching sections of cable into space on rockets. A "climber" — his version of an elevator car — would then be attached to the cable and used to add more lengths of cable until eventually it stretches down to the Earth. A counterweight would be attached to the end in space.

Edwards likens the design to "spinning a ball on a string around your head." The string is the cable and the ball on the end is a counterweight. The Earth's rotation would keep the cable taut.

The elevator would be powered by photo cells that convert light into electricity. A laser attached to the platform could be aimed at the elevator to deliver the light, Edwards said.

Edwards said he probably needs about two more years of development on the carbon nanotubes to obtain the strength needed. After that, he believes work on the project can begin.

"The major obstacle is probably just politics or funding and those two are the same thing," he said. "The technical, I don't think that's really an issue anymore."

 

[Zon]

Unless, as it seems, you're suggesting that a guy who does orbital mechanics for a living must obviously take a back seat in these matters to a guy who apparently excels in writing grant requests?

I note that you feign to not understand the part that you didn't quote. Your straw man is as thin as your veracity. I think anyone can see clean through it. Or perhaps you did understand it and to quote it would so obviously render your strawman completely naked.

Over the past couple of years I've read a dozen articles about the potential for building a space elevator. Some very well educated research scientist wrote a few of them and none mentioned any one thing or problem or group of problems that would invalidate building a space elevator.

[RightWhale]

The asteroid counterbalance would take an interesting piece of work. It would have to be brought into geosynch orbit itself at first and after attachment move out to whatever they said, 60,000 miles. This would take longer than weeks. We better start right away.

[patton]

Funniest comment I have seen all week.

[r9etb]

I think youall are both right. IIRC There were several experiements, and none completely successful.

TSS flew on two missions. In the first, it got stuck. In the second, it made it out to 20 km, and did in fact generate a significant electrical current (until the tether broke) --seems to me it was a couple of amps at a healthy voltage.

The orbit of the increased tens of miles (it was traveling above the CM, and thus faster than orbital velocity at its altitude), and the Shuttle moved downward several miles.

[Oztrich Boy]

I'll bid 6850, but not 7000. In

I can do it for 5890.

[Captain Beyond]

Yeah if we could only make everything at the equator of the Earth the 51 state or states. Talk about your gerrymandering wheww. It would be like a bunch starved pit bulls fighting over a dead cat to get in that action. Didn't Snoopdog want a company to make a video game where pit bulls turn into humans then into pimps. Maybe he should check out politics. But I digress.

[RightWhale]

That's right. They would balance, but only on average, not at any particular time. The machine would have to store energy and probably at many locations along the cable.

[Don Joe]

The cable will be torqued in one direction by the rising object, and in the other by the descending one -- it will look like a 62,000 mile high letter "S".

Well, that's when the top cab (traveling down) is on the leading side of the ribbon and the bottom cab (traveling up) is on the trailing side.

When they reverse their trips, they'll meet in the middle in a most spectacular way -- presuming of course the ribbon can sustain the sideways force from each cab as it moves up to speed (the lower cab) and down to zero (relative) MPH (the upper cab).

[sawmill trash]

"The major obstacle is probably just politics or funding and those two are the same thing," he said. "The technical, I don't think that's really an issue anymore."

Thats exactly how it is at my house !

[Don Joe]

I note that you feign to not understand the part that you didn't quote. Your straw man is as thin as your veracity. I think anyone can see clean through it. Or perhaps you did understand it and to quote it would so obviously render your strawman completely naked.

Good grief, get a grip on yourself! Sheesh!

Is there some reason for that nutty display of emotion?

Over the past couple of years I've read a dozen articles

LMAO!

I don't know the guy, but I rather suspect that r9etb may very well have written more articles than you've "read" over that timespan. (And if not, I suspect he's more than qualified to do so, if he felt like taking the time from his paying work.)

[olde north church]

Stairway to the Stars or Stairway to Heaven

[Question_Assumptions]

Excellent point about the tidal forces. I can't believe that this is the first time I've read about that concern. Given that the tether will likely be stretched to its limits by vertical forces, demanding that it handle any horizontal stresses seems problematic. Of course not speeding up to orbital velocity is also what made the SpaceShip One flight so much simpler than an orbital launch. I don't think a lot of people are grasping that it isn't vertical velocity that's the issue but horizontal velocity. And there is also the whole issue of how to hang the thing and what goes wrong if it doesn't hang properly. But even the tether could be useful for getting space generated power to the ground or ground generated power into space. Of course it would be one whopper of a terrorist target.

[Zon]

Given that the thing has to be dropped down to Earth from GEO, and that all of the necessary stuff (actually, twice the mass of the cable) has to be launched up there on rockets, how many heavy lift launches do you suppose it would take to do that? Answer: several, at $300 million a pop. Let's say it takes 10 launches (very unrealistic), so that's $3 billion out of your budget already.

Well, apparently you don't understand how the ribbon/cable will be constructed. From what I read it will be built up in a series smaller ribbons. That's besides they [point for you are discussing money hurdles rather than technology hurdles.

LOL! Put up or shut up about expertise, Zon.

I have several times more confidence in the research scientists that have written articles on the subject -- taking the time to do so because it is not really taking much time away from their career priorities as it is aligned with them -- I have more confidence in them than you wasting your time here. I know how to evaluate expertise and acknowledge that you have more in this field than I do but I'm putting several well educated research scientist that have very successful careers up against one lone r9etb. You can pull your foot out of your mouth any time now. Your use of non sequitur acknowledged

[XBob]

144 - "TSS flew on two missions. In the first, it got stuck. In the second, it made it out to 20 km, and did in fact generate a significant electrical current (until the tether broke) --seems to me it was a couple of amps at a healthy voltage. "

It seems to me there were several attempts on each mission, before they finally gave up. And the first one, I remember distinctly, as it was obvious, the scientists and engineers had never been fishing, as they tried to spin out the line without any weight on it, and keeping a reasonable tension, so it just wouldn't deploy, and turned into a real mess on the drum. On the other mission, I think they finally solved that problem, but one literally blew up, and they tried again and it finally broke or was cut from stress.

[Don Joe]

I can't believe that this is the first time I've read about that concern.

I was born the party-pooper. :)

Seriously, it's been bugging me for a while, and I finally decided to bite the bullet and voice my two cents in public. (My relatives are probably tired of hearing me bitch about it every time I see an article proclaiming its bright future.)

[Don Joe]

Wow, that "Zon" is quite the jovial character, isn't he. That's an amazing death-grip he's got on your ankle. His teeth must be killing him by now! :)

[BluSky]

Lose the cable and counter-weight proposal.

I prefer the space elevator in Tim Allen's movie, 'Galaxy Quest' for interstellar travel.

[XBob]

Any comment from some engineering types about my gross calculations?

81 - "ROTFLMAO - a bit of quick calculations reveal that this cable would have to support about 9-10 million pounds, just to support itself, without any stress."

I know of nothing that will support that weight, even carbon nanotubes, plus all the stresses which will be necessary to compensate for.

[Don Joe]

one literally blew up

That's the one I was thinking of. I remember something about them being stumped as to the cause, until they did the math and figured out how much juice it had tried to carry before failing from overload.

[Question_Assumptions]

I was born the party-pooper. :)

Of course none of the neat stuff in science fiction seems to be possible if one understands anything beyond basic physics. The universe just doesn't want us to get out of the gravity well cheaply or travel faster than the speed of light, it seems. And that's not even touching on the magical science fiction energy systems that ignore not only energy storage issues but the implications of even a small inefficiency in the system converting even a small fraction of that massive energy into heat that has to go somewhere.

Seriously, it's been bugging me for a while, and I finally decided to bite the bullet and voice my two cents in public. (My relatives are probably tired of hearing me bitch about it every time I see an article proclaiming its bright future.)

Oh, just go to the Smithsonian Air and Space museum and their "What's next?" exhibit and that will kill any optimism you might have. My wife had to listen to me rant not only about the display on the working NERVA engines that were cancelled and scrapped because, well, "nuclear stuff is bad" but also about the display asking whether we should disturb the pristine environment of Mars with a human presence. If physics doesn't kill mankind's expansion into space, leftist environmentalists worried about things like disturbing the "environment" on a dead planet sure will.