Anchored Tether Space Elevators

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A Tapered Cross-section Lunar Space Elevator

The author was just one of many people, as stated by Arthur C. Clarke in the back of his book "Fountains of Paradise", to independently think of the anchored tether earth-space elavator concept, that would be supported by a counterweight beyond GEO as the Earth rotates, providing the centrifugal force on the mass beyond GEO to hold up the weight below GEO. The author thought of it in 1969, but there were at least two earlier ones, in 1960 and 1966. And we all eventually realized that there was no material existing that had the required tensile strength-to-density ratio to be able to support even its own weight.

Bu the author did not let the idea completely go, after mulling it over a long time, and came up with the concept of an anchored lunar tether space elevator through L-1 and was able to show that space-rated fiberglass in a tapered configuration ws strong enough for it density to do the job:

A Lunar Space Elevator Designed In 1972

Revisiting Anchored Tether Earth Space Elevator Concepts

Since the sudden new interest in the anchored space elevator concept, apparent at Brad Edwards' tremendous NASA-grant sponsored presentation at ASCE's Space 2002 conference in Albuquerque, NM, (although its initial effect was to eclipse the second technical paper on my KESTS to GEO concept I had made at the same conference, "Kinetically Supported Bridge Vehicle Lift to GEO" ) the subject of tether space elevator concepts became renewed in myself, stirring up memories of my own ideas on the subject, back in the early 1970's. Edwards' presentation was based on the availability of a sufficiently strong tether material, a 100 GPa 1300 kg/m3 carbon nanotube compasite said to be being made in Japan already in industrial quantities. There was an enthusiastic contractor also making presentations at the same session: they were ready to build, if someone would come up with the money. (So why be interested in a mere concept like my KESTS to GEO paper described, when a somewhat similar usefulness system was in the ready to build status.)

Edwards' proposal, in dazzling animation, would be a tapered tether, like my 1972 Mooncable concept A Lunar Space Elevator Designed In 1972, and would use climbers, somewhat also like my earlier design. In the first years after the ASCE 2002 Space conference, ocasionally I would revisit the idea of a tether space elevator; I struggled to again figure out what strength-to-mass ratio structural material was needed for an Earth anchored tether space elevator, something I had done back about 1970 dashing my hopes for such a thing. My math skills were not up to doing the full direct calculation, so I did the final integration by manual summation of the weights, and found to my surprise that even a 80 GPa 300 kg/m3 tether material would work for a constant cross section tether, opening up a whole world of different options.  I put the calculations on one of my web pages, which someone pointed out to a MIT PhD student Gassand, who subsequently wrote a paper on it, but which somehow got ignored. So I wrote a paper which included it in part, including the calculations, for presentation at the 2007 SES space elevator conference. I sent the paper in over the internet, along with the Powerpoint presentation for it, per the conference request. But I was having transportation problems of my own, and it turned out that a sudden strange hole in my car's cooling system would have prevented me from driving to the conference - or even to an airport in time to do my presentation in Albuquerque; my submitted paper then seemed to vanish, and I was subsequently unable to get any response from the conference people, nor even get a copy of the proceedings, which I had paid for as part of my registration. But here the technical paper is, in case of interest:

Long Range Electromechanical Power Transmission Along Space Transportation Structures

Mulling over all the events during my four decades of efforts to provide key concepts for the rapid expansion of civilization into Earth orbit in my time,  I have ruefully concluded that there are many social and business pressures going on, a very complex stew of motives and opportunities, and huge fortunes at stake. No wonder I got treated like a party crasher, trying to rock their boat. Even looking back to NASA's purpose at its beginnings, it may even now only be committed to keeping America's space technology expertice active enough to fend off any other hostile nation's attempt to put nukes on the Moon etc aimed at us. Not really interested in using my concepts for rapidly using existing knowledge to expand civilization into high Earth orbit; what a can of worms that would be for the business-as-usual authorities.

So, anyway I got to live out the actualization of my conceptual designs, even for that new space elevator design, in the virtual world of science fiction; and it is the first concept explored in my book "Building Up" And perhaps you will enjoy reading it as much as I enjoyed writing the novels, some day. I found that writing high-tech sci fi was lots more fun than writing and presenting formal technical papers involving the same concepts.