Welcome to liftport: Do you have information about studies that have been done? You should not say know nothing, as most people know some things about photons.  Neil

Hi Joel: A harp string is not much longer than one meter. The ribbon is 36 million meters from anchor ship to GEO altitude, so frequencies will be much lower. The ribbon will be some what heftier at jet stream altitude to compensate for worst possible conditions. My guess is flutter will be a problem = rotation of the ribbon about it's vertical axis. There will also be stretch transients due to attaching the climber at the anchor ship and any speed changes of the climber. I assume a winch at the anchor ship which can tighten or loosen the ribbon to avoid excessive stress or temporary slack ribbon. In my opinion it is important to know to the second when transients will reach the anchor ship and pass each climber. It is thought that transients will travel more than one mile per second on the ribbon, but perhaps much slower if a Hoytether is used as it is somewhat like a fishnet. My guess is the stretch transients can help move the climber up the ribbon. I agree we need to use a ribbon (instead of a round cable) to tether a large balloon at an altitude of 40 kilometters or more, so as to be sure we understand how the jet stream will vibrate the ribbon.    Neil

The 0.38g of Mars helps a lot. GEO altitude is about 20,000 kilometers instead of 36,000 kilometers. So the ribbon from surface to GEO is thinner and lighter. I think the counter weight ribbon is also less total mass.
The problems are we have not been to Mars, nor delivered even a tiny fraction of the needed mass to Mars. Constructing a space elevator with no people closer than about 100 million kilometers has too many uncertanties to build a reasonable plan of action.  Neil

While it is not politically correct governments should tell medeocre and worse citizens that they are part of the problem if they conceive children. On the other hand sucessful persons with good genes and good attitudes, should have as many children as they can reasonably care for, emotionally and financially. These children will likely find solutions to the growing impact of humans on our planet. I am opposed to forcing people in this or other matters, but we could sensibly limit the income tax exemption for dependent children to adopted and foster children. We could also increase the pressure on single mothers, to be better mothers or find useful employment, especially those with a long history of needing assistance.   Neil

The Edward's plan is about 91,000 kilometers of of very thin ribbon deployed from GEO. This requires lifting perhaps ten tons to GEO altitude. This starter ribbon would be used to add strengthening strands each weighing perhaps 1/4 ton to the ribbon until it is strong enough to lift a larger pay load than 1/4 ton. If I understand your plan, 4 starter ribbons are needed to build the 10 kilometer pyrimid at GEO altitude, upside down. To extend your pyrimid toward earth would require many more ten ton rocket launches almost to GEO altitude. Also your pyrimid needs a counter weight beyond GEO altitude so the center of weight remains at about GEO altitude until the pyrimid is attached to Earth or an anchor ship.  Neil

Perhaps we can build such a structure in the far future. We have not tested the ideas to much more than one kilometer so far, so a logical intermediate step is 1.5 kilometers, perhaps 2 kilometers. My guess is the base needs to be at least 10 kilometers by 10 kilometers (10% of the heigth) which increases the cost by about 100 times. In most locations the structure needs to withstand winds up to about 200 kilometers per hour, plus aircraft collisions, earthquakes, temperature cycling, ice and snow loading. My guess is the Iffle tower shape has no advantage over a pyramid.
Building the 3d or 4th space elevator like an upside down pyramid might be good, as the earlier elvevators could deliver the materials to the top at low cost.

A_M_Swallow gave good answers. The vicinity will be a no fly zone. A small plane can make several close passes without hitting the ribbon. The plane can be shot down if it does not change course. The propulsion laser can possibly damage the aircraft. I think the anchor craft and it's back up will have propulsion lasers that can continiously deliver several megawatts to an airplane. Bright colors, will add weight to the ribbon, and won't help much, because of the small size of the ribbon, but visable laser holigrams might make the ribbon look bigger and brighter. Enough lighting to be effective attached to the ribbon, would interfer with the climber rollars and could easily have enough weight to halve the pay load of the ribbon, even with optimistic projections for CNT strength.
I agree the ribbon will cut though the plane like a knife, in some senarios, but the ribbon will also break in many senarios. Hopefully a heliocopter can catch the end escaping slowly into space, and reatatch it to the anchor ship.   Neil

Yes the process can be repeated, but the weight is too much for a vertical SE. If we can produce light weight million gause superconducting magnets, They can climb Earth's magnetic field which typically reaches to about GEO altitude. We are not likely to achieve a million gause in this century.   Neil

I will post the following to www.conocophillips.com if I can get some more good ideas. Obviously the space elevator would be a big help with the 800 metric tons. Some experts are of the opinion that L1 = almost two million kilometers sunward from Earth is the best place for a solar shade. Others of us think LEO = low Earth orbit = about 500 kilometers above Earth's surface is best. Typical LEO satellites are shaded by  Earth 45% of the time. An approximation of a polar orbit, however is solar synchonous = The orbiting sun shade will stay over two PM or other time continiously as the Earth turns. This means the satellite is shaded only briefly over the North pole for a few minutes in November, December and January, and similarly over the South Pole in May, June and July. A thousand kilometer = 600 mile diameter sun shade would reduce Earth's average temperature by at least 0.9 degrees f = 0.5 degrees c, which may be more cooling than is desirable, assuming that 1/2 percent of Earth's sunlit surface is completely shaded by the satellite on the average = total eclipse. An L1 sun shade this size would appear as a tiny speck on the Sun and produce negligible cooling of Earth. I believe we can instal the shade satellite in solar sychronous orbit 500 kilometers above the surface by 2012, with lots of funding.
More details: A = 3.24 times radius squared = 3.14 times 250,000 square kilometers. At one kilogram per square kilometer, that is 800 metric tons of thin film in orbit. Spinning at one turn per day the disk of film will remain approximately flat, in spite of occasional holes made by space junk and micrometeorites. One kilogram per square kilometer is one milligram per square meter of film = 100 picograms per square centimeter. This is an average thickness of 10 nano meters, if my arithmetic is correct and the density of the film is 1. The disk will face the distant stars continiously unless we cause the axis of rotation to tilt 360 degrees per year to face the Sun, so that it can be an effectve sun shade. How do we turn this increadibly flimsy disk?   Neil

Why didn't I think of propellers?   Neil

 
The following is a revised version of the idea, I just posted at http://www.conocophillips.com Your comments may prove valuable in the unlikely event that the judges want more info: A free flying platform shaped like an equilateral hexigon 200 feet on each edge is supported by six hydrogen filled balloons attached by 330 feet of ribbon (600 feet at the three alternating corners of the platform) A 7th smaller ballon partially fills the center gap and is attached near the center. Two flying electric generators = FEG are attached by 3 miles of tether. The two FEGs supply electricity to the equipment on the platform, keep the platform reasonably level, and allow minor movement of the platform with respect to the prevailing wind. The platform flies at 100,000 feet, or higher, depending on the weight of the platform and it’s equipment. Development of CNT = carbon nano tubes with great specs, will be helpful, but almost that high is practical with existing materials.
A 35 foot flat mirror which can be warped to slightly concave, will hang from a 300 foot ribbon under the center of the platform. The mirror will be aimed by thrusters similar to those used to control the attitude of the space shuttle. Alternately, the two FEG can aim the mirror. The mirror reflects sunlight through a hole in the clouds to existing large solar sites up to about 50 miles away.
If this is done from LEO = low Earth orbit, I believe the minimum illuminated spot size is larger than any existing solar energy receiving sites. An altitude of 100,000 feet, however, does provide near optimum spot size for existing large solar sites, which will produce more power when the beam is available. A large fleet of similar flying platforms are needed to increase the power output of solar sites throughout the Northern hemisphere. This is why I suggested hydrogen, instead of helium, as the world likely cannot produce enough helium for a large fleet. Fire and explosion hazard is near zero above about 20,000 feet. Hot air balloons are an alternative, but the 100,000 feet may not be practical until we have CNT or equivalent with great specs.
When no solar site is within range, crops can be warmed slightly by the beam. Cities and ships at sea warmed, and cloudy days made a bit brighter. A few minutes of extra sunlight can be provided near sunset and sunrise. I believe the beam will be in demand as soon as it becomes available.
If a million platforms are flying, the Earth will be cooled perhaps 0.001 degrees f, but tangled FEG tethers should be rare even if little effort is made to prevent tangling. The platform should be white on top to reflect sunlight toward the balloons and space. Warming the balloons will allow a slightly higher altitude.
The 35 foot mirrors were built for Star Wars = Strategic Defense Initive almost two decades ago and may be presently available as surplus items. Some additional scale up is likely practical, but large numbers of platforms are likely better to provide near constant power at each solar receiving site.
More details: The angle of the sun and the solar site will occasionally be unfavorable, and the balloons will occasionally shade the mirror (at low latitudes in June and early July) If a second platform is within a few miles a double bounce may be practical, or the mirrors can heat the balloons allowing a slightly higher altitude, which will sometimes be desirable. The platforms can be used to help predict the weather, other science, as cell phone towers and if sufficient power is available from the FEGs, radio, radar, SSP and TV towers. Vacationers may find a few days living on a platform exciting.
The FEG tethers need to be several miles long to get a wind speed different from the platform speed, otherwise neither lift, nor electricity are produced. See http://www.skywindpower.com
Lift off from the ground will require a day with little wind, but wind gusts are rare above about 20,000 feet. The steady wind does not apply mechanical stress to a free flying structure.
Free flying balloons launched North of the Equator, circle the Earth several times and can be recovered near the Arctic Circle. This cheap energy will bring opportunities to property near the Arctic Circle. I suggest that the beam be sent at no cost to anyone who energizes a transmitter with proper code, priority being given to those who are willing to pay for the priority code.
The Southern hemisphere will be impractical due to the high cost of recovery in Antarctica.  Neil

It is disappointing that no one has annouced the availability of CNT ribbon, several times stonger than Kevar and cheap, but maybe next month. The owner of such a break though might keep quiet until production was ready to fill orders. Dr. Bradly Edwards is optimistic.   Neil

It likely is not practical to send electricity up from the anchor ship.
I get 10560 times 10 to the 5th ounces for the mass of the polar ribbon = one billion ounces divide by 16 = 66 million pounds = 33,000 tons, so you need to think much less than one ounce per linear foot.
6877 MPH times 24 = 165,000 miles per day divided by 6.28 should give the radius of GEO orbit = 26,282 miles, subtract 4000 (Earth's radius) = 22,282 That is a bit higher than the altitude of GEO orbit, but close enough for most purposes, so the arithmetic checks.
A solar sail can only produce thrust equal to about 0.05% of Earth's gravity, so the statite needs to be far enough from Earth so Earth's gravity is about 0.05% of the surface gravity. An ion engine powered by solar panels can get somewhat closer to the North pole than 200,000 miles. Both solar sail and ion engine (or equivalent) can provide redundecy for an upper end station. 300,000 miles is practical as the moon is never over the North pole. The Statite needs to lift the weight of the ribbon and climbers, so the solar sail needs to be very large. More climber energy is needed as centrifugal will not reduce the gravity for a North pole elevator. The ribbon will need to be stronger. Radiation is more of a problem due to Northern lights, but perhaps less of a problem in the Van Allen belts. Logistics to the elevator base is more difficult in winter. Icing of the ribbon will be an increased problem, but North pole storms, meteors, space junk and lightning may be rare. Payloads for the moon and beyond will not get the large speed boost the Edwards type space elevator produces.
The anchor station can move thousands of miles from the optimum location with only small performance loss. The statite can also move some from the North pole, but the counterweight for the Dr. Edwards type space elevator will stay over the torid zone, even with a solar sail pulling on the counterweight.    Neil

Item 4: A_M_Swallow is correct. The only way to prevent the ISS from dragging the balloon at impossible speeds would be to move the ISS to approximately GEO orbit = altitude about 22,000 miles. That would take months with 10,000 ion engines of present design, but more powerful ion engines (or equivelent)may be available soon.
A resupply craft and crew transport craft would have to be developed for the ISS at GEO altitude and that may be as costly as going to the moon. The crew of the ISS at GEO would be subject to several times the radiation they experience at LEO.  Neil

15,000 miles per hour, attachment speed is likely possible with present tether materials, but there are disadvantages. 1 Cost triples, maybe more. 2 Safety factor is reduced. 3 The tether (and auxillary equipment) has more mass than the space shuttle can lift to orbit, requiring multiple trips and assembly in space. 4 The tether needs to be tapered = perhaps 10 times the cross sectional area at the center of rotation, 5 Reduced payload due to a nasty jerk about a minute after attachment. Before the jerk, the pay load is stretching the tether (like a bungy cord) toward Earth's surface. 6 The release speed is about 19,000 miles per hour which is too fast for a circular orbit, but likely a plus for getting to GEO orbit and beyond.
When, and if, CNT with great specs becomes available, lower attachment speed
and altitude with bolo lengths up to about 22,000 miles will be comparatively easy. G loading of the payload will also be reduced except the jerk may be worse,
unless the bolo tip is powered to minimize the jerk. The liftport web site is doubling up on words at the end of some lines.  Neil