Where to Anchor My Space Elevator

Question

Thanks to the recent discovery of handwavium ^‡ filaments that can in principle be extruded to any length, we will be able to build space elevators sooner than most people would expect.

The interesting question is where to put it. The first state to deploy a space elevator will likely have a significant cost advantage and could potentially control all space activities.

Now I was initially considering minimizing the distance covered, so putting it on top of a tall mountain at the equator, such as Mount Chimborazo in Ecuador:

On the plus side, it would look damn cool.

But a country like Ecuador probably can't seriously consider doing this on its own, and experience with the Suez and Panama Canals suggests that maintaining control of the facility in a foreign country is not always feasible, despite any initial investment.

Moreover, the need to steer the cable in orbit around the occasional satellite that might get in the way might mean we want to be able to move the ground-socket about quite a bit, in addition to the thrusters and lasers in orbit or along the cable.

So would we rather place it in the open ocean? Perhaps somewhere in the doldrums?

That would have the advantage of being free of national boundaries, and close to sea-traffic so large objects could be shipped by sea to the elevator. But I worry about storms.

So, what is the best location for a space elevator?

Answer 1

Sea based near the area of Curacao seems a good choice.

http://www.hurricanecity.com/city/abcislands.htm Aruba,Bonaire & Curacao Islands history with tropical systems

Longest gap between storms 25 years 1892-1918

How often this area gets affected? brushed or hit every 6.50 years

Average years between direct hurricane hits.(5) once every 28.60 years

Average MPH of hurricane hits. (based on advisories sustained winds, not gusts) 103mph

Statistically when this area should be affected next 1 year overdue

Last affected by 2007, Sept 2nd Hurricane Felix passes just north with 105mph winds while moving west,area sustained TS force winds & some flooding .

This areas hurricane past 1877 Sept 23rd 105mph from the ENE 1886 95 mph Aug 26th from the East. 1892 Oct 8th 95mph from the east. 1932 Nov 3rd 95mph from the NE,HURDAT lists this as a Category 2 hurricane at 12.9N, 71.3W at 12 UTC just north of Aruba 1954 Oct 8th Hurricane Hazel passes just north while moving West with 125mph winds

Also http://www.budgettravel.com/blog/storm-free-caribbean-islands-during-hurricane-season,12404/

Also http://spaceplace.nasa.gov/hurricanes/en/

Additional Edit

Near the Galapagos islands which is closer to the equator said to be not affected by cyclones

!http://www.noonsite.com/Countries/Galapagos/pacific-planning-advice !the Galapagos and Easter Island can be dismissed at they are not affected by cyclones

!http://www.scubaiguana.com/html/galapagos_information.html !The coldest month is September. There are no storms in Galapagos

If someone can add another link for Galapagos Islands it will be much appreciated. Looking for data on places that don't experience storms always gives results on vacation websites.

Additional Edit 2

http://www.pbs.org/wgbh/nova/space/edwards-elevator.html

Q: I think the space elevator is a terrific idea, and I understand how it works, but how would you maintain stability above, say, 1,000 feet? Couldn't one severe storm start the apparatus twisting and swaying, bringing the structure down? Jim Suss, Marietta, Georgia

Edwards: Due to the dynamics, the elevator is held extremely tight and will be fairly rigid. Storms and winds will blow it around and move it. We will need to deal with twisting and oscillations, but one thing to remember is that the frequency of this system is seven hours, a very slow oscillation. The other aspect is that the anchor will be located in the eastern equatorial Pacific Ocean at a place devoid of major storms, wind, or lightning, just north of the doldrums.

Q: Would the space elevators have to be placed exactly on the equatorial line, like a satellite in a geosynchronous orbit, to maximize the centripetal force of the Earth's rotation to stiffen the elevator cable? Or would they work equally well anywhere on the surface of the Earth? What would be the "orbital physics 101" considerations here? Attila Gyuris, Lake Matthews, California

Edwards: The elevator can be placed anywhere within 20 degrees of the equator due to the dynamics, but the performance is best at the equator. As you get off the equator, the ribbon goes up at an angle and eventually is lying close to the ground and is unusable.

Another viewpoint on equatorial and non-equatorial space elevator

http://gassend.net/spaceelevator/non-equatorial/

non Equatorial uniform stress space elevator

http://gassend.net/spaceelevator/3rd-conference-notes/OffEquator-Talk.pdf

Answer 2

Have you considered Brazil? It's a large country with solid economic growth, so it could subsidize construction. It has launch capacity already. The equator runs through it and intersects the coastline, so easy access to freight shipping. Shipping could come straight from the US or Europe, while Japan and other Asian countries could get there via the Panama Canal. A location near Macapá seems quite feasible.

I'm not convinced that moving the grounded end is necessary. It would probably take a long time for the change to propagate up the cable. I think that satellites might have to steer to miss it rather than it trying to miss satellites. If the cable does have to move, it may be better to attach thrusters at orbiting level rather than try to move the cable from one end or the other.

Answer 3

Most of the space elevators stories I've read have placed it at Mt. Kilimanjaro. Perfect location.

I believe that the reasons for anchoring a space elevator on a continent are:

1. Storms are much weaker than at sea. Continents are where hurricanes, this planet's most powerful storms, go to die.
2. Access to greater transportation infrastructure.
3. Almost 6 km "for free" of elevation. Every little bit of a space elevator costs even when made from handwavium.
4. Easier access to the anchoring substrate.
5. Only 3 degrees from the equator.
6. Still able to take good advantage of sea ports.

Answer 4

Important considerations for the location of a space elevator:

Political stability - Elevator must be placed in the territory of a politically stable country. Construction and operation of an elevator will require an enormous financial investment, and likely be funded and operated via multiple countries. Countries will not invest in such a venture unless it is located in a politically stable location. See Panama Canal as a previous example.

Equatorial or non-equatorial - An elevator located away from the equator offers better options in regards to politically stable countries and the possibility of milder weather. However, the work done by Blaise Gassend (http://gassend.net/index.html) and others has demonstrated that the elevator needs to be relatively close to the equator especially since deploying the elevator initially will be highly difficult away from the equator. Construction of a space elevator may also have multiple phases which will be easier to accomplish closer to the equator.

Land or sea - The complexity of a modern offshore drilling rig and the possible risk of loss of an ocean based platform are two reasons why a floating offshore elevator platform would not be optimal. The ease of access and the reduced cost of transportation to any land based facility will also easily outweigh the benefits of any floating platform. Ask any sailor and they will tell you they would rather be on land during bad weather than at sea. Thus, a land based facility offers more benefits with less risk than a floating platform.

Mountaintop or sea level - Once technology allows us to produce the 22,000+ miles of carbon nanotubes to build a space elevator, saving a few miles by locating the elevator at a higher land elevation will have minimal savings. Other considerations like access to a transportation, weather, nearby population, and environmental concerns will likely be more significant drivers of the location decision.

Weather - The enormous financial investment and the risk of damage to a space elevator requires that it be placed in as mild a climate as possible. Regions frequented by hurricanes/ typhoons or strong electrical storms would need to be avoided. Areas like the Caribbean would be avoided while the relatively calmer western coasts of most continents would be acceptable.

Transportation access - The materials to be moved up a space elevator need to first reach the elevator site here on earth. Efficient transportation networks will be required and consist of roads, ports, and airports.

Population density - Cape Canaveral, FL, is a good rocket launch site due to the ability to launch rockets over the ocean. When a mishap does occur, impact to residents is normally avoided as debris will fall into the ocean. To reduce risks to people, a space elevator should be located on or next to an ocean and away from any large population centers.

Environmental Impact - Any elevator site will need major infrastructure improvements constructed around it and thus could not be placed in an environmentally or ecologically sensitive area. For example the rich diversity of the Galapagos Islands, would rule it out as a possible location due to the expected damage done to its ecosystem.

Given these considerations, several immediately viable locations for a space elevator are realized. The coast of Ecuador and French or U.S. territorial islands in the Pacific. A multinational effort could be established in Ecuador with a long-term lease of a small parcel of land, see Cuba's Guantanamo Bay example (https://en.wikipedia.org/wiki/Guantanamo_Bay_Naval_Base). Ecuador meets many of the important considerations and would benefit immensely from the economic activity surrounding the facility. More remote sites with less desirable transportation options and weather would be several of the French or U.S. territorial islands in the Pacific like Tahiti, American Samoa, Howland Island or Baker Island.

Answer 5

To add to the existing answers for advantages and drawbacks of a sea-based anchor (e.g. storms and easy accessibility) - and citing from Wikipedia:

Mobile platforms (large oceangoing vessels) advantages over stationary bases are the possibility to move the base station, therefore outmaneuvering trouble; like high winds, storms, and space debris, yes even space debris as movement of the lower anchor will also move the rest of the ribbon so to avoid impact. This of course requires accurate tracking of space debris - which fortunately is already done by NASA and others.

Another advantage is the fact that the oceanic anchor could be placed in international waters, thus less trouble with a single nation's legislation (maybe).

High mountains and fixed bases however seem to offer a simpler design, less costs in logistics and the benefit of using its natural high.

Answer 6

If we for a moment drop the idea of putting the anchor on the equator, the first place that comes to my mind is the Tibetan Massif. But since that is very hard to reach, and this extra 5 kilometers doesn't mean much, that may seem a silly idea.

The reason it isn't silly, is that the anchor must be placed on solid rock and in teritory where there are no earthquakes. It would be dumb to lose such a project by bad positioning, like they almost did with Hubble. Given that, the Equator and Africa are bad ideas. The sea is a very bad idea, it would be quite complicated unless we combine the ideas of a tower-like elevator, which would be raised from stable ocean bed to the stratosphere and from there an line like elevator would be anchored.

If we position this contraption on the equator and in the lifting air currents area it could work. Mind that any extra forces would be great to overcome our gravity.

It also occured to me that we don't know the nature of gravity, and learning that in the near future might make an elevator project look like the projects for horse dung storage in New York in the beginning of the XXth century. And cheers to that.

But for a kind of cheap prototype - it is just a hunch, I didn't do any math - I would bet on the Tibetan Massif. I know, politics, Russia, China - but unless we calm down and work on this one together in peace we aren't going nowhere, in the first place. Somebody dumb enough might just strike it with bomb or plane and here we go.

Answer 7

I suggest anchoring the elevator on an artificial island off the coast of Singapore. Two reasons for this:

1. Singapore is only one degree north of the equator, making it ideal from an engineering perspective. Its relatively central position in Southeast Asia, as well as its close proximities to China and India, make the location immensely accessible.

2. The Strait of Malacca is already one of the busiest shipping lanes in the world. meaning goods bound for orbit won't need to make a costly detour.

Ideally the artificial island's location means administration of the anchorpoint would fall under the joint jurisdiction of the Singaporean and Indonesian governments. Technically Singapore can do it themselves, and considering two of Singapore's official languages are English and Mandarin - the global lingua fraca and the most commonly spoken language of the local superpower - they would be ideal. But joint control, even if it's just a formality, is necessary to maintain good relations with Jakarta.

Answer 8

Since ya'll downvote without bothering to cite, why don't you try reading: http://en.wikipedia.org/wiki/Skyhook_(structure)#Non-rotating

In fact, given that we're hand-waving the strength problem away - you'd be dumb to have a space elevator at all, since that requires power to climb it. When instead you could go to orbit for free. See the rotating options on that wikipedia page.

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Don't tether it to the Earth. Drop it down so it's reachable by planes, then you've got a lot fewer problems if something hits it/severs it; everything above the sever doesn't become a potential kinetic impactor, and if you've put rockets along the length up, you can fire them and take the rest away as well.

If you place it in the ocean, and when it drops you'll take out coasts on both shores.

Added bonus, since its terminal end is not anchored, you can move it around if the country / ocean you're above becomes problematic, or doesn't want to pay you enough / trade demands - you go somewhere else.

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If you have problems anywhere along the length of your elevator, it's going to lose its balance, and become a nice falling object.

As long as the damage happens to the half which is below the equilibrium point, the remainder of the portion above the severance point will fly off into space (ie: not becoming an impactor).

If you've secured one end to the planet, any damage above that point has to become an impactor (ie: up to 99.9% of your elevator) unless you have coping mechanisms.

The simplest coping mechanism is to quickly spool up anything that's not severed, or to rapidly put a larger weight further out. You can also joist anything below the equilibrium point up with rockets, assuming you cut the tether at the ground level - otherwise you're merely putting off impact until your rockets run out of fuel.

If you're tethered to the Earth, then you have a pretty hard limit on how much remaining elevator length you have. If you lose it right at the equilibrium point, you will need a rocket which can lift the whole remaining mass up out of the gravity well (expensive), as well as being able to release it from the ground.

If it's not tethered to the ground, you have a lot more options for anything that's not severed from your structure (ie: the only risk is up to half of the elevator below the equilibrium point (which is also shorter since it doesn't reach all the way to the ground). You also have more time to react, since you've got 10K feet (for example) before impact starts to occur.

The simplest way to do this, is to have a landing bay/pad at the lowest end of the non-tethered elevator, and if anything happens, sever that weight (which is lowest, and probably weighs less than your at-risk portion of the elevator). Yes, you drop something from 10K feet, big splash. You don't lose the rest of your elevator. In this example, the tether/ribbon/elevator is longer, or has a counterweight past the equilibrium point to balance the weight of your landing bay.

Or, to be more clear:

How does cutting the bottom 5-30 km from a 36000+km ribbon prevent it from becoming a kinetic impactor?

It prevents 35,940+ km worth of ribbon from being an impactor, which if the top 30km of your tethered ribbon got severed by terrorist, space junk, micrometeorite, etc would (most likely) be the case.