Space elevator ? How can it work?

**chayced** · Dec31-09, 12:28 PM

At this point putting a space elevator on mars is the equivilent to putting a Starbucks there. When it does become possible it will probably be ancient technology.

**dr dodge** · Jan4-10, 07:36 AM

ok, I have been thinking about this (I know, VERY dangerous)

Wouldn't surface tension of the gases of the earths atmosphere follow the cable higher up the cable. That could potentially cause odd plasma reactions when it got to space. transmitting power up it would require it to either be 2 cables next to each other, or some sort of induction/coax kind of deal. and it would have to be like trying to push massive megawatts thru a tera-ohm resistor.
OK, we make the cable, how are we supposed to get it to the earth. upper atmosphere winds would drag it around all over while we are trying to get it to the ground. think about lowering a piece of fishing line off your roof to touch a 1/4 inch square a basketball on the ground. even on a zero wind day, you'd have to send out so much extra cable just to finally get a grip on it to drag it back to the point of attachment. at the point in time that we were just ready to attach it to the earth, the static on that thing would be...well
How much slack would it need to allow for the wobble of the earth? The pulling on the cable would try to pull the satelite out of orbit on the way up, and shove it out on the way down. you'd need a spool of cable the size of the moon, and a tensioner the size of rhode island to keep the cable tension correct.
IMHO, the following formula applies:

elevator idea+(many$$$$$$$$)=stick and deceased equestrian

dr

**Gfellow** · Jan5-10, 09:26 AM

"Space Elevator" has been in my Google Alert for quite some years now, and I have noticed a tenfold increase in the chatter on the subject. It would appear that the concept is rapidly becoming part of the collective consciousness.
It is notable that the Japanese are looking to spend 8 billion on such a project, and while that might seem an insignificant fraction of the final cost, it makes for interesting seed money.

Whether building a space elevator is feasible can be an arguable subject, but IMHO there is little doubt that someone will try. The rewards are just too big to ignore. I won't go into the mass/lift ratio advantage here, but considering the relatively small resource outlay, the political stature and military advantage that a space elevator will afford, will ultimately be too tempting for any number of powerful nations.

As a real-estate speculator, my focus of interest is where it might be located. For logistical, physical and political reasons, my bet is the island nation state of Nauru. The island is on the equator, minimum security issues, harbor installations, commercial runway, tarmacked road rings the island.

The only other places available on, or near the equator are either politically insecure, or have no infrastructure.

**FredGarvin** · Jan5-10, 11:24 AM

Originally Posted by Gfellow

...but considering the relatively small resource outlay, the political stature and military advantage that a space elevator will afford, will ultimately be too tempting for any number of powerful nations.

I'm not sure of what you mean by that. There is nothing involved with this fantasy that would be small. The amount of resources required will be huge, especially in the manufacturing sector.

You do bring up an interesting point about the military. Not so much in its use, but in how anyone could ever hope to defend a space elevator if someone really wanted to put one out of commission.

**DaveC426913** · Jan5-10, 11:30 AM

Originally Posted by FredGarvin

You do bring up an interesting point about the military. Not so much in its use, but in how anyone could ever hope to defend a space elevator if someone really wanted to put one out of commission.

Yes, this is definitely something that cannot be ignored. I think it will limit any one nation from attempting it. The space elevator is too much of a game-changer.

**DaveC426913** · Jan5-10, 11:33 AM

By the way, I REALLY think we should make a concerted effort to popularize the nickname: It's a MAGIC BEANSTALK, or BEANSTALK for short. The name fits it perfectly.

Come on everybody, we can make a change if only we truly BELIEVE!

**FredGarvin** · Jan5-10, 11:37 AM

Magic Beanstalk...I like it.

**Gfellow** · Jan5-10, 02:11 PM

Originally Posted by FredGarvin

I'm not sure of what you mean by that. There is nothing involved with this fantasy that would be small. The amount of resources required will be huge, especially in the manufacturing sector.

Greetings FredGarvin - Perhaps comparable to the Panama Canal in terms or resource and effort? Was it worth it?

You do bring up an interesting point about the military. Not so much in its use, but in how anyone could ever hope to defend a space elevator if someone really wanted to put one out of commission.

Several famous quotes of different personages come to mind. The slightly misquoted General Nathan Bedford Forrest's "git thar fustest with the mostest," comes to mind, or perhaps "command the high ground" of which there are too many authors to count.

From a combative point of view, the nation-state with the space elevator would definitely hold a strategic advantage over an opponent. The loss of the bridge out of the gravity well would be regrettable, but assuming you have ferried up a considerable quantity of resources, it would be of little consequence once you have obtained the sustained ability to look down upon and strike your enemy during a crisis.
From a tactical point of view the gravity-bound opponent might think twice about initializing hostilities.

**DaveC426913** · Jan5-10, 02:18 PM

Originally Posted by Gfellow

From a combative point of view, the nation-state with the space elevator would definitely hold a strategic advantage over an opponent. The loss of the bridge out of the gravity well would be regrettable, but assuming you have ferried up a considerable quantity of resources, it would be of little consequence once you have obtained the sustained ability to look down upon and strike your enemy during a crisis.
From a tactical point of view the gravity-bound opponent might think twice about initializing hostilities.

OK, well that's an escalation even above what we are talking about. If there is the slightest hint (or even if there isn't) that the elevator will be used for strategic purposes, the whole world will rise up against them before it ever gets off the ground.

**Gfellow** · Jan5-10, 02:24 PM

Originally Posted by DaveC426913

MAGIC BEANSTALK

Nice! Another possible suggestion? "Jacobs Ladder" This name has a messianic flavor and would galvanize the religious conservatives to your side:
"...He came to the place and stayed there that night, because the sun
had set. Taking one of the stones of the place, he put it under his
head and lay down in that place to sleep. And he dreamed that there
was a ladder set up on the earth, and the top of it reached to heaven;
and behold, the angels of God were ascending and descending on it! And
behold, the LORD stood above it [or "beside him"] and said, "I am the
LORD, the God of Abraham your father and the God of Isaac; the land on
which you lie I will give to you and to your descendants; and your
descendants shall be like the dust of the earth, and you shall spread
abroad to the west and to the east and to the north and to the south;
and by you and your descendants shall all the families of the earth
bless themselves..."
(I realize we are getting a little off-topic here, but I am sure the admins don't mind a bit of humor.)

**Gfellow** · Jan5-10, 02:41 PM

Originally Posted by DaveC426913

If there is the slightest hint (or even if there isn't) that the elevator will be used for strategic purposes, the whole world will rise up against them before it ever gets off the ground.

Do you believe the US would have placed a man on the moon if the USSR was not on the agenda? Major resource hungry efforts by nation-states have a combative proponent. They may never mention it, but it is still there.
Ideally, the space elevator ought to be an international effort - perhaps it might happen that way. However, if that does not occur, the advantage afforded to an individual nation-state would eventually be too great a temptation.

**FredGarvin** · Jan5-10, 03:37 PM

Originally Posted by Gfellow

Greetings FredGarvin - Perhaps comparable to the Panama Canal in terms or resource and effort? Was it worth it?

Greetings to you as well.
Like I have mentioned before, the Panama Canal is not even close in the terms of what is required. The pieces and abilities to build the canal were already in place and understood. There just needed to be a huge man power commitment (and money). With the bean stalk we are talking about using materials that have not been invented yet, and building techniques that do not exist. Once we figure that out we have to figure out how to do it on a massive scale. Then you bring in all of the other issues also mentioned like satellites, etc...Honestly, I can not think of anything on this planet that is a good comparison to what needs to be done. Perhaps the Great Wall of China...

**Gfellow** · Jan5-10, 05:14 PM

Originally Posted by FredGarvin

...huge man power commitment (and money). With the bean stalk we are talking about using materials that have not been invented yet, and building techniques that do not exist.

I put it to you that we have emerged into a new paradigm. The adept control of manpower and resources was the great triumph of the past two centuries, a tool we now take for granted. The flower of our epoch is the additional thrust of efficient research towards a given end.
When Kennedy told the world the US was going to put a man on the moon in a decade, the NASA science staff were gobsmacked. Although it is what they wanted, they had not really taken the time to sweat the details. However, it turned out to be a confirmation that this paradigm was upon us.

The REAL issue comes down to, 'is it worth it?'.

As a rule, nation-state military systems tend to be conservative and usually remain complacent unless there is an imminent and obvious threat. Seen in this light, the space elevator can be dealt with in three ways:
1. A space elevator race could ensue between nation-states.
2. An agreement might be forged to share costs and build an international space elevator, the advantage being that no individual nation-state gains an overall advantage.
3. Agreeing amongst themselves not to build it at all, which would suggest a conspiratorial component historically uncharacteristic of such entities.

**mugaliens** · Jan5-10, 05:25 PM

Originally Posted by dr dodge

OK, we make the cable, how are we supposed to get it to the earth.

You build the geosynchronous location, along with the counterweight, then slowly lower the cable while simultaneously extending the counterweight further out. Once the cable is anchored on Earth, you can extent the counterweight further in order to apply tension along the length of the cable.

**DaveC426913** · Jan5-10, 07:47 PM

Originally Posted by mugaliens

You build the geosynchronous location, along with the counterweight, then slowly lower the cable while simultaneously extending the counterweight further out. Once the cable is anchored on Earth, you can extent the counterweight further in order to apply tension along the length of the cable.

You stopped reading halfway through his sentence. He explains why he thinks getting it to Earth might be problematic.

**Phrak** · Jan5-10, 08:40 PM

There are about 400 satellites in geosynchronous orbit. At present, launch costs run from $4K to $40K per kilogram dependent upon dependability of launch. Taking $10K/kilogram cost as a near-future cost for rocket launches, how much will the cost equivalent of a space elevator be to amortize 4000 satellites to break even with rocket lauch profits? (Hint: you need to know the average mass of a satellite.)