Perhaps simple knots and loops, with welding at the tips. Nanotubes threaded through each other?

The Chinese have made similar strides.

Toroid over the tubes are nice. Who knows, perhaps even--dare I say it? A double helix?

If anything, it would help if a large mass (an HLLV upper stage--like an empty shuttle external tank for floorspace :smile: ) like an asteroid was at the end of the tether to keep it taut. There was mention of one asteroid that people think they may capture. Such a body would be mined, and allow the elevator raw material with which to grow. A good metal asteroid about the size of a football stadium would have enough ore to pay off the national debt. Any remaining ceramics could be heated and blown into huge glass bubbles. If another bubble was blown inside the first, and the space between filled with clear material, you would have spherical living areas with a very thick wall that would be transparent.

For more information about Asteroids that could be captured:
http://www.ledger-enquirer.com/mld/ledgerenquirer/4880200.htm

http://burtleburtle.net/bob/physics/cruithne.html

http://www.dogpile.com/info.dogpl/search/web/Captured%2Basteroid%2Btether

We have all heard about the mobile tether platforms at sea. You may have an opportunity to get one cheap, depending on just how the Sea Launch platform fares. Now you all know that I am an advocate for heavy lift. But if I absolutely had to do without, I might press Sea Launch into service as a trial elevator ribbon testbed.

 You launch the Sea Launch Zenit booster while the Sea Launch platform is along the equator, as it already has to be in order to launch anything to equitorial orbit. A charged statite tether with the huge currents at the poles using both a solar sail and the great current to repel the ground magnetically might in some respects be simpler--but enough of that for now.

Once the Sea Launch's Zenit booster is away, its payload achieves geosynch in a position directly over the Sea Launch platform it lifted off from--and dangles a tiny proof-of-concept tether to the platform--which is still unmanned for safety. If all goes well, the launch-pad becomes a future elevator car base--even using the same clamps at the bottom to hold cars/cables.


A much larger HLLV can then place additional material which can come down the cable on a reel, and add to the pre-existing tether put in orbit by Sea Launch--a ready tether platform with its own propulsion that can swing the elevator from side to side to avoid debris. It can never be used as a launch pad again, so long as the tether is there. If it works, you have your space elevator--if not, you still have the Sea Launch for the usual Zenit launch.

Anything to reduce length. In the fighting words section I discuss alternatives. Here are a couple listed.

Alternatives are Dr. Hyde's Starbridge of LLNL and another is the Synchrodyne ("The Synchrodyne--A Dynamically Supported Skyhook, Part I. Seady State," ACTA ASTRONAUTICA 45 (1999) pp. 143-153.) Perhaps you are already familiar with these alternatives.

Weather modification to me is not quite so frightening as a 22,000 mile lightning rod that runs through the ionosphere to ground. We saw how the tether on the shuttle became over-charged and broke, so I cannot imagine the voltage from Trans-ionospheric pulse pairs that all of a sudden have a path to ground. Large bits of icing are not your only concern. The elevator car and the handling facility may even need to be Faraday cages to keep certain circuits from shorting out.

We hear a lot of doom-and-gloomers and technophobes talk about HAARP and such--which I have no problem with--but, to be honest, the concept of a huge space-to-earth lightning rod is a bit concerning. There is a lot about the global electrical circuit we do not yet understand. Not too long ago, if an airline pilot reported huge, red jellyfish like things in the sky that flashed into and out of existance--he would have been called crazy for reporting sprites, elves, and perhaps most relavent here, the upward spraying blue jets that may accompany upward superbolts (often called positive giants). Kluwer, I believe, has an interesting book by Stenhoff called Ball Lightning, which talks about the vulnerability of aerospace structures to certain charges. There are all sorts of atmospheric beasties, from TIPPS to Kapitsa waves.

A 22,000 mile lightning rod run through all this may do nothing, or--on just the wrong evening, you could discharge the whole of the global electrical circuit in one enormus lighting stroke the length of the ribbon that would kill even folks in a Faraday cage, which can be penetrated under certain conditions. The lighting stroke would be massive, with a huge corona that could cause heart failures and fry computers for miles. What such an event would do is uncertain, but smaller scale tests are needed. On the other hand, you may have free power.

The problem with that is, as you charge a tether, you can raise its altitute, as you discharge a tether, you lose altitute.

We have to be careful with this, one way or the other.

My point was that people seem to fall all over themselves to keep from building adequate launch vehicles. We call HLLVs expensive, then call for space elevators. The idea of using smaller launch vehicles to assemble space elevators comes from some of the same folks who call ISS a bad idea. Why? Because it is built 20 tons at a time. Energia could place 100 ton pods up to LEO, and service them with simpler orbiters that may have been less reusable--but more serviceable.

 We have been brainwashed into thinking robotic spacecraft are a solution to everything. It takes all of JPL to run the two small robots that would be considered failures if they tried to replace a lineman's job. Remember the Darpa Challenge? Those were true robots, and miserable failures which could not so much as complete the course.

Heavy-Lift gives you engine-out capability, where EELVs do not. Space elevators will be best constructed by Heavy lift. remember, and EELV can place 20 tons in LEO--but less in geosynch. So it would take a HLLV to put EELV type payloads in the orbit you need them. Or you could boost a completed product once assembled lower down and dangle as you go with the charged tether gaining altitude. The Space Daily message board had an interesting Space Message Board in the ROCKET SCIENCE page Space Travel.

Alternatives are Dr. Hyde's Starbridge of LLNL and another is the Synchrodyne ("The Synchrodyne--A Dynamically Supported Skyhook, Part I. Seady State," ACTA ASTRONAUTICA 45 (1999) pp. 143-153.) Perhaps you are already familiar with these alternatives.

As far as my contributions to the forum--read on.

I think ice loading is your biggest concern. Ivan notwithstanding, most hurricanes do not form along the ITCZ along the equator, where your space-elevator must be. Storms form to the north or south of this region, and move away. For info, check out www.caribwx.com and the forums at www.stormtrack.org where many storm chasers like Jim Reed may visit. They are the folks you need to talk to about this.

Once again, it is ice loading and huge falling fragments of ice that can come down like huge spikes of hail upon your elevator car that will be your biggest threat.

Consider that.


In the mean time, a good test of future fibers would be to see them used in very large, Pressure-Fed HLLVs like Sea Dragon, which will follow shuttle derived HLLVs for demonstrators. You are not going to get around the need for big rockets, no matter how hard you try, and impac problems will threaten you just as was done with Columbia, especially if you mean to have space elevators move with any speed at all.

Perhaps this is outlandish, but a massive solar statite that uses solar pressure to keep it over the poles will allow shorter tether lengths and can be used as reflectors to beam out ahead of hurricanes, and sap life giving convection out from in front of them, so their fuel is dried up. Such structures would be good for space solar power--and if big enough could dangle an elevator to the poles. Antarctica is actually a desert, so you may actually have less icing problems than you would punching through the dense moist atmosphere along the tropics  A statite dangled Space Elevator would not need to be 22,000 miles tall like BeanStalk One. A statite dangle space elevator only need to be a couple of hundred miles tall, though.

I am new here, and I feel the need to be the one to break the Fighting Words section in. I often post over at www.starshipmodeler.net and visit www.starshipmodeler.com

I can be found in the Real Space thread and have many links on the Buran vs. Dyna-Soar pages.

Let me throw down the gauntlet by saying that a Space Elevator system will only work by construction of Heavy-Lift (80-100 ton-to-LEO) Launch Vehicles. Everything else is rubbish, as I will explain below in my article:

******************************************************

Heavy Lift IS Needed

I was disturbed by the anti-Heavy Lift sentiment expressed by Don Robertson in the Sept. 20 issue of SPACE NEWS ("No Need for New Launchers Now "). He could not be more wrong. The key to lower launch costs is not launch frequency, but delivery in bulk. We do not see motorboats crossing the Atlantic with goods, but very large containerships plying the waves.

The EELVs cannot in fact lift over one-fifth of the Saturn V's 130-140 tons to LEO. The EELV is an albatross no better than the near-extinct Titan IV it replaces. The critics of ISS forget that the big reason behind the constant delay of ISS is the fact that it is assembled 20 tons at a time.

A modular HLLV like Energiya that had the hydrogen engines under the External Tank (ET) could carry a simple Buran-type orbiter or swap it out with 100 ton payload pods. Five of those and ISS would have been finished years ago.

The critics of HLLVs also don't seem to understand the term 'margin.' It would take five three-core Delta IV 'heavies' with one RS-68 hydrogen engine per core to place 100 tons to LEO in five launches of 20 tons each. This means you would have to throw 15 RS-68 engines away. I can place 100 tons into orbit expending only three or four RS-68s mounted under our External Tank in an Energiya type system that has engine-out capability, unlike the EELVs. If one of an HLLV's hydrogen engines go out, I can burn the others longer. This cannot be done with the Delta IV. The RS-68 (a good engine now) has had trouble with turbopumps before, so some engine-out capability should be mandatory. The Delta IV has been taken out of the commercial launch market, and Boeing's largest commercial rocket is now the Sea Launch booster, Zenit--which started life as the Energiya HLLV liquid-fueled strap-on booster. The two-nozzle version of the four nozzle Zenit (RD-170) engines is the RD-180 used by Lockheed-Martin's Atlas V EELV.

Both Boeing and Lockheed-Martin now must rely on technology that was developed for Heavy Lift in the first place, which makes their attempt to fight Heavy-Lift development all the more sickening to those of us who watched as these two companies put off rocket development in favor of Stealth systems and $200 billion Joint Strike Fighter that can neither deflect asteroids or disable ICBMs--seeing as large BMDO payloads need HLLVs in order to work as intended, i.e. shoot down at missiles in boost phase, not shoot up at warheads, decoys, buses and nosecones already on their way down.

If it wasn't for Heavy-Lift, Boeing and Lockheed-Martin would not now have their two biggest commercial launchers.

Now the two companies rely on Russian equipment. They still don't get it. What we really need is all-American technology with Russian philosophy. All American RS-68s from Boeing can be placed under Lockheed-Martin's External Tank giving us Heavy Lifters with engine out capability and no reliance on other countries.

The Russian philosophy is what we must adapt--they understood that 'too much truck is better than not enough.' Remember, their R-7 Sputnik launcher was considered overlarge, and yet it and the bigger Proton have become their best sellers. By the time we completed our EELVs they could carry no more than these other Russian launch vehicles which had glutted the market, leaving the EELVs too little--too late. Now the Aerospace companies are left the EELV Albatross they now wish to hang on our necks.

The EELVs would continue the failed 'build it twenty-tons-at-a-time-and-they-will-come' mindset that left us with the ISS. This philosophy is even worse when it comes to exploration since hydrogen boil off will be even more of a problem when you adopt the pieces/parts type assembly.

If we want large production runs, then get the most bang for your buck. Using the Delta IV approach, you must expend 15 RS-68s to get 100 tons to orbit. By launching five HLLVs with only three RS-68s apiece, you sell your 15 RS-68s but you have 500 tons in orbit in the same amount of time. Real Space commerce will only be successful if done in large scale--not by dropping ME-163 Komets out from under Learjets.

The Titan IV often cost a billion dollar a shot. An HLLV should be no more than this. But remember, that equates into $200 million for every 20 tons of HLLV payload--putting it at least even with EELV costs that are likely to exceed $250 million for every 20 tons or so--with no engine out capability!

 But the real cost of medium lift is higher, since you will need five upper stages for every 100 tons placed into orbit by five EELVs as opposed to having but one engine-equipped External Tank deliver the entire load to space, retaining a large empty shuttle External Tank that, like Skylab, can give industry real floor space. Gene Meyers of Space Island Group ( www.spaceislandgroup.com )understands that much at least, and sees the industrial potential only large scale can bring.

The money saved by ending JSF and the Discovery Programs could field an HLLV in but a few years with much more capability. Or we can continue to send puny bomb-disposal robots to Mars and risk the lives of EELV-riding astronauts docking and refueling fifty-eleven times just to get to the moon, while the Russians continue to make money off us, because they had the good sense to build rockets big in the first place.

BTW, We need to get rid of John Jumper and have Lance Lord--or better yet Pete Worden--take over as head of the Air Farce and have the fighter jocks who lord it over the space people take a back seat for a change. I think the NAVY would have a better mindset when it comes to logistics.

And yes, it was me who wrote the controversial Space Daily piece "IS THE AIR FORCE THE ENEMY OF SPACE?"

Read General Medaris' book COUNTDOWN FOR DECISION to learn how the AF stole space away from the Army. The soviets knew to keep space away from the prima donnas in their Air Force, and kept rockets inside the army.

Rule #1 in Space advocacy. Keep the Air Force the @##! away from it.

Publius Rex

http://groups.yahoo.com/group/HumanSpaceflight/message/1105
http://groups.yahoo.com/group/SpaceADG/message/3580
www.k26.com/buran
www.buran.ru