The economics of space elevators - Are they financially feasible?

MarsGuy2012 · 2003-04-23 00:13:06

Well,

You guys sure are busy! Five pages in just one day!

Anyway, I'm all for the elevator. I'm sure the demand will increase when it is built - especially if there is a colony on Mars to go to.

Just got a few questions and suggestions:

1. What do we do about all the space junk floating around between LEO and GEO?

2. Why would we beam power from a SPS to Earth with microwaves if we can just string a cable down the elevator? As I understand about 50% of the power is lost in the atmosphere with a microwave system.

3. I just don't see the point of using disposable capsules if you can bring them down on the elevator. Remember, most of them will be empty so you won't loose capacity at a one to one ratio.

4. I'd make the Elevator with two ribbons up to GEO for up and down travel, then one extra long ribbon extending out from GEO to slingshot vehicles out to Earth/Mars cyclers, Saturn, or whatever.

5. How fast could a vehicle go if you put it in the slingshot ribbon and just let the sucker go - no brakes?

6. How fast would you get loads to GEO if you had a constant excelleration - say 1.5 gs all the way there?

Phobos · 2003-04-23 01:32:47

1. What do we do about all the space junk floating around between LEO and GEO?

The base of the elevator is a moveable platform that will shift the ribbon accordingly to avoid any major satellites/space junk. The buzz phrase is "active avoidance."

2. Why would we beam power from a SPS to Earth with microwaves if we can just string a cable down the elevator? As I understand about 50% of the power is lost in the atmosphere with a microwave system.

The ribbon of the elevator is far too long to be a good conductor. Resistance would eventually kill any electric current sent down from it, certainly a lot more than 50%. Another problem is that even if you could send power down the ribbon the anchor station will be hundreds of miles from civilization so you'd have another power transmission problem. It's easier to just microwave the energy. I'm going on the assumption that you mean this power is meant for consumption by the general public and not the elevator itself. The lifters will be powered by ground based free electron lasers.

3. I just don't see the point of using disposable capsules if you can bring them down on the elevator. Remember, most of them will be empty so you won't loose capacity at a one to one ratio.

For the first elevator it's best to keep things as simple as possible which means having only one ribbon and you don't want to waste time bringing down a lifter when you could be sending multiple lifters up in it's place. The lifters are pretty much just simple frames with motors attached anyway, nothing all that special or particularly expensive.

4. I'd make the Elevator with two ribbons up to GEO for up and down travel, then one extra long ribbon extending out from GEO to slingshot vehicles out to Earth/Mars cyclers, Saturn, or whatever.

That's always a good upgrade option but I think it would be best to focus first on just getting the elevator working using one tether for simplicity. If the first one works it's a safe bet that more and better elevators will be built. And the counterweight of the elevator does extend beyond GEO significantly enough that payloads could be launched to Mars and the asteroid belt and everywhere else in the inner solar system. The elevator wouldn't work if the actual counterweight was planted in GEO.

MarsGuy2012 · 2003-04-23 09:22:14

Thanks Phobos,

You say the counterweight should be out past GEO. That's fine, but will there be a station at GEO? At GEO you could build as much as you want without having to worry about throwing the elevator of balance, since it is the center of gravity. Also the slingshot effect would be so much greater if a ribbon was the only thing extending past GEO.

What about superconductors for the power transmission? I don't know what the EPA would say about microwaving the Earth. Just had a thought: We could build SPSs on the elevator at LEO as long as they had a counterweight on the other end. Then the power would only have to travel a hundred km or so instead of thousands from GEO. What do you think?

I don't like the logistics of ancoring the elevator out at sea. I suppose any space junk could be avoided by "flexing" the elevator. Use thrusters or muscle-like contracting devices to twist it away from any collision. It wouldn't have to flex too much everything we have put in space is smaller that 100 meters, right?

Bill White · 2003-04-23 09:26:38

Anyway, I'm all for the elevator. I'm sure the demand will increase when it is built - especially if there is a colony on Mars to go to.

Thanks! This shows the potential for a chicken/egg dilemma.

Does HighLift build an elevator and then look for demand? If so where do they find the money up front?

Whether we use soph's numbers (which do conform to a slide show presented at the HighLift conference) or Tim's numbers (which conform with Dr. Edward's book) or the higher cost figures I suspect will end up being the "true" numbers, the elevator will need to be used 24/7 for 10 to 20 years to recover the capital investment.

Few people will invest billions of dollars "on faith" that enough users will be found. At $10,000 per passenger or even $50,000 per passenger, to amortize $10 billion or $20 billion or $50 billion we are moving lots and lots of people into space.

How many people do we need to lift over a 10 year period and will that many people want to go? True believers say "SURE" but are we so sure?

Cargo? Can solar power sats compete on price with alternate energy on Earth? Are solar power sats a "cheaper" source of power than new nuclear plants?

How much mass must make a one way trip to LEO to amortize the billions needed to build an elevator?

IMHO - put a colony on Mars BEFORE the elevator and you create demand for the elevator. yet how do you afford a colony on Mars before the elevator is built?

Chicken? or Egg?

clark · 2003-04-23 09:48:48

You don't need Mars- the moon is all the reason you need.

A continually manned base on the moon will require a cheap and reliable system to move people and supplies between them.

Closer, and more economic benefits can be realized on Luna, than on Mars.

MarsGuy2012 · 2003-04-23 09:53:36

I'll take a shot at your chicken eg question Bill.

A Mars colony or at least a base will be built before an elevator. Why, because it will use proven technology. We have sent probes to Mars with rockets before, so we can build bigger ones and send people. Banks and politicians can both understand that so the funding will be more readily available.

Transportation to Mars with rockets will cost in the millions. Let's say you can build a 100 tonne capacity Earth to Mars vehicle for a billion dollars. That would cost $10 million per tonne. Once an elevator is built you don't have to get the cost into the thousands you just have to beat the $10 million dollar price. If say you offer your elevator services at 1 million dollars per tonne, any government/company sending explorers to Mars will jump all over it. You will be the exclusive transportation provider to Mars.

gotta go...I'll be back.

Bill White · 2003-04-23 10:10:03

The Moon? Fine by me - lets just not make this an either/or argument. In other words lets not argue for the Moon to the exclusion of Mars or argue the reverse: Mars or Bust! Space is space.

Lunar mining has great potential, yet the economic downside is that plentiful lunar raw materials will decrease the per kilogram market value of those materials. Helium-3 will be a tremendous resource, just not yet. Likewise I have concerns about whether Earth's economy can generate sufficient demand to consume sufficient lunar raw materials to amortize the costs of building a mining settlement.

clark, I am confident *YOU* understand that bringing a 100,000 tonne platinum asteroid into LEO for carving up and sale on Earth will cause the price of platinum to plummet which means we cannot calculate profit based on $500 per pound, or whatever the platinum market is at today. Some space advocates seem to ignore this fact.

So while I *DO* favor lunar minng and space tourism, and whether we get the chicken first or the egg, lets not put all those eggs in one basket, okay? Putting settlers on Mars simply will create considerable demand for space travel - a demand that may not be fully rational from an economic perspective - hence a more in-elastic demand that will not swing with the cycles of the commodities markets.

Invest in people, not commodities. Economies based on commerce do better than economies based on mining or drillign raw materials - its the "Oil Curse" argument all over again.

Finally, by analogy, I LOVE the space elevator (one good egg) but lets not bet everything on one technology. I also LOVE hypersonic skyhooks (another good egg?). Add a robust spine to Rutan's new spacecraft and "hook" that thing at apogee - the shock loading will be awesome - but you do get into space. . .

Bill White · 2003-04-23 10:20:14

MarsGuy2012 writes:

A Mars colony or at least a base will be built before an elevator. Why, because it will use proven technology. We have sent probes to Mars with rockets before, so we can build bigger ones and send people. Banks and politicians can both understand that so the funding will be more readily available.

I follow this way of thinking. . .

I believe the idea that going to Mars (or the Moon) must await cheaper new technologies is a dead end or red herring because the economic demand needed to justify the development of such new technologies will not exist until after such settlements are built. Chicken and Egg.

The traditional free market fails because there are not sufficient rational profit motive reasons to spend billions and billions getting into space. Hence we need non-rational (not irrational, non-rational) justifications for entering space to break through the dilemma.

"Unleashing" the free market ain't going to do it. Besides, what "leash" are we talking about anyways?

clark · 2003-04-23 10:22:21

Lunar mining has great potential, yet the economic downside is that plentiful lunar raw materials will decrease the per kilogram market value of those materials.

Ah, but the price is dictated by the supply of other sources. Lunar mining is really water extraction, oxygen production, and fuel production.

It also makes a great spot to start building those government telescopes (you know, the gigantic arrays).

I understand what you're saying though, but i think the economic downside is limited by the extraction process. If you're mining the stuff, you mine it at an economical rate that dosen't undercut your production costs. Self control man.

clark, I am confident *YOU* understand that bringing a 100,000 tonne platinum asteroid into LEO for carving up and sale on Earth will cause the price of platinum to plummet which means we cannot calculate profit based on $500 per pound, or whatever the platinum market is at today. Some space advocates seem to ignore this fact.

I agree to an extent, but i wouldn't discount the space advocates view. Diamonds come to mind as a similar analogy for supply-price control. If you have a rock in LEO filled with platnium, you don't dump it on the open market- that is foolish and needless. You extract at a rate that is profitable- and leave the darn thing floating there like the virtual piggy bank that it is.

Economies based on commerce do better than economies based on mining or drillign raw materials - its the "Oil Curse" argument all over again.

Economies based on commerce, have at their heart, some manufacturing economy that engenders and maintains the commerce section of the economy. You can't have an economy solely on commerce- there has to be some sort of production side that is the catalyst. Unless you know of anything in history that has broken free from this equation. Do you?

Finally, by analogy, I LOVE the space elevator (one good egg) but lets not bet everything on one technology.

Yet this one idea, this one egg, destroys any economic reason to maintain other technologies that allow access to space. If it is as cheap as it is, it can't be beat. Can it?

What WOULDN'T the elevator be good for (assuming it meets it's optimitic goals)?

Bill White · 2003-04-23 10:27:22

Ah, but the price is dictated by the supply of other sources. Lunar mining is really water extraction, oxygen production, and fuel production.

If I chose to invest to found a Mars settlement, the simultaneous founding of a lunar mining camp (and a Phobos mining camp) would be an obvious parallel investment well worth the extra money.

Yet the starting point to "break the ice" may need to be non-rational. . .

Bill White · 2003-04-23 10:29:36

Yet this one idea, this one egg, destroys any economic reason to maintain other technologies that allow access to space. If it is as cheap as it is, it can't be beat. Can it?
What WOULDN'T the elevator be good for (assuming it meets it's optimitic goals)?

Yes, the potential plainly exists that the elevator will make the cost to LEO so low that any other investment in Earth to LEO tech is foolish. Yet until someone builds an elevator or invents cheap plentiful CNT we are stuck in neutral since no one will invest in CNT or pay to build an elevator UNTIL return on investment is assured. Catch 22! - to switch analogies -

Low prices can be bad. . .

clark · 2003-04-23 10:40:21

Yet the starting point to "break the ice" may need to be non-rational. . .

I know where you're coming from here... and it is plausible. My 'non-rational' idea is something like this:

National security is tied to space. Our economy, thus our way of life, is increasingly tied to the machines that hang over our heads. This is true for all industrilized, and emerging countries-space related industry has the net effect of improving national economies, as well as improving national security.

As with our maritime history, national governments will see their role as protecting the commerce of space. That means we need more military capabilities to act, and react in space. This also serves to add extra protection to our homeland, which everyone agrees is important.

So the military wants responsive capabilities. They want flexible options, with multi-purpose tools to account for various contingencies. And they will want it cheap.

That means space platforms. That means large scale construction. That means large scale power production and fuel production on Luna.

The non-rational catalyst is the very 'rational' idea of self defense. Of course it dosen't make sense in a larger view.But in a more immediate way, it makes all the sense in the world.

Yes, the potential plainly exists that the elevator will make the cost to LEO so low that any other investment in Earth to LEO tech is foolish.

:;): Think about what that would mean if something were to happen to an elevator in use for 20 years....

Bill White · 2003-04-23 11:08:52

National security is tied to space. Our economy, thus our way of life, is increasingly tied to the machines that hang over our heads. This is true for all industrilized, and emerging countries-space related industry has the net effect of improving national economies, as well as improving national security.

US national security (military and economic) does depend on space based assets. I agree totally.

Is that security best assured by expanding US human presence in space? Isn't that security better assured by doing everything possible to prevent others from having access to space? A US monopoly on access to space?

How can that monopoly be justified if the US has begun commercial exploitation of space?

clark · 2003-04-23 11:17:05

Is that security best assured by expanding US human presence in space?

If people are going to go into space, they might as well be our people... and our 'friends'. As more people go into space, the military will look for ways to deal with possible problems of having all of these people in space. I don't think the military is realy interested in preventing general access to space, just being able to respond in space. Besides, it works counter to the general direction of military procurement, which is increasinly depenadant (a predicted continuing trend) upon the commerical sector for military hardware.

People in space make the militaries job easier in some respects becuase they can utilize the civilian space infrastructure when neccessary.

Isn't that security better assured by doing everything possible to prevent others from having access to space?

Secuirty is assured through the development of capabilities that allow us to deny access to space, when we choose to. We don't need to control it, we just need to be able to control it when we have to.

A US monopoly on access to space?

Don't we already have that? The US is the dominant user of space assessts. Everyone who makes the decisions want to continue this precedent.

How can that monopoly be justified if the US has begun commercial exploitation of space?

Semantics and politcs.

Bill White · 2003-04-23 11:21:54

Fair enough, clark. Our points of disageement have become too minor to mention.

soph · 2003-04-23 12:29:10

Bill: CNT has enough commercial and industrial applications that that alone might get the funding needed to build the entire elevator. I've heard that Highlift plans to produce and sell CNT once it's developed to help fund the elevator.

CNT is remarkable stuff.

Bill White · 2003-04-23 12:32:14

Bill: CNT has enough commercial and industrial applications that that alone might get the funding needed to build the entire elevator. I've heard that Highlift plans to produce and sell CNT once it's developed to help fund the elevator.
CNT is remarkable stuff.

Why do you need an elevator to make and sell CNT? Investing in CNT seems like a "good idea" for lots and lots of reasons and the elevator is merely one such use.

My arguments in this thread all assume the existence of very inexpensive and plentiful CNT. No CNT? Then no elevator.

If HighLift manages to make billions of dollars by developing and selling CNT and then they choose to donate those profits for building an elevator, all I can say is "God Bless!"

soph · 2003-04-23 12:33:50

Other way around.

Bill White · 2003-04-23 13:14:55

soph, what is your understanding of the time frame for the development of facilities to manufacture vast quantities of useful CNT?

tim_perdue · 2003-04-23 13:24:53

My arguments in this thread all assume the existence of very inexpensive and plentiful CNT. No CNT? Then no elevator.
If HighLift manages to make billions of dollars by developing and selling CNT and then they choose to donate those profits for building an elevator, all I can say is "God Bless!"

Highlift has an update on their website that there is already a 1-Km CNT thread that has been successfully created. This is huge. Only a few months ago I had read that the longest nanotubes were in the 2-mm range (I may have read outdated info).

CNTs are going to be useful on earth for composites that are made of graphite today, such as airplane wings. You can also envision an "Uber-Kevlar" to make bullet-proof vests, gloves, tents, AND inflatable space-habs.

I don't think any of this amounts to $10 billion in profit to fund the elevator. The market isn't big enough to envision $10 billion profit in a competitive marketplace.

BTW - if you can swallow highlifts numbers, or anything approaching them, the space elevator is profitable all by itself. You can make a business case around it if you can manage the risks.

soph · 2003-04-23 13:27:07

Bill: in 5 years, we'll start to see widespread application of CNT in everything from advanced computers to high end conductors, perhaps even to fuel cells.

clark · 2003-04-23 13:31:31

Do you have any idea what this means to the automotive industry?

Fuel cells? Of course.

Basic construction?

My god, the stuff can replace anything that we currently use steel for...which is everything.

At least that has been the promise.

Hey, tim, can you give directions to where you found the info on the 1KM CNT?

tim_perdue · 2003-04-23 13:39:08

My god, the stuff can replace anything that we currently use steel for...which is everything.

You might be confused on that one. It can replace steel for TENSILE strength, but not compressive strength to the best of my knowledge. So you could hang the empire state building by a CNT cable, but you could not replace the beams that currently support it vertically.

If it had 100x the compressive strength as steel, yes this would completely and totally shatter every industry. Cars would be light as a feather for example. Airplanes would ditch aluminum and titanium. Etc.

For building applications, imagine it would work well as a re-bar for concrete. Currently fiberglass is mixed in some concretes. CNT mixed in would be 10x better, plus you have concrete's incredible compressive strength and you eliminate concrete's dreadful tensile strength.

Hey, tim, can you give directions to where you found the info on the 1KM CNT?

It's in the "Going Up" newsletters. Click on "downloads" on their website and read those - they're exciting.

http://www.highliftsystems.com/converte … -V1N3.html

"Now, two independent groups have reported kilometer-length CNT composite fibers with good interfacial adhesion in different matrices."

Bill White · 2003-04-23 13:58:01

For building applications, imagine it would work well as a re-bar for concrete. Currently fiberglass is mixed in some concretes. CNT mixed in would be 10x better, plus you have concrete's incredible compressive strength and you eliminate concrete's dreadful tensile strength.

Use it on Mars as re-bar mixed in Mars-crete and you need to call it "Mars-bar"

Sadly, the "Going Up" report of 1 km CNT appears un-verified. IMHO once 1 km CNT is verified we will see that news make the front page of most mainstream press.

clark · 2003-04-23 14:02:45

Sadly, the "Going Up" report of 1 km CNT appears un-verified. IMHO once 1 km CNT is verified we will see that news make the front page of most mainstream press.

I'm looking for some more info on this since the "going up" report was made in Oct 2002.

I think I can imagine why there is little reporting on this matter.

The creation of nanotubes on the kilomter scale is an industiral revolution waiting to happen. The simplef act is that nanotubes, produced in mass, will be in high demand by just about everyone.

Everything from computers to cars can benefit from this matieral. Now, I might imagine that whoever discovered how to produce in such large volumes is going to want to protect the considerable fortune this ability represents.

EDIT:

Info on Nanotubes:
http://www.chattanoogan.com/articles/article_32378.asp
Feb 10,2003

Dr. Roberto said Oak Ridge National Laboratory is building four major facilities for the study of nanotechnology over the next four years. ?There is more action at ORNL on this technology than in any other lab in the country right now.?
With the United States expected to spend more than $700 million in research and development of nanotechnology in 2003 and with more than $2 billion being spent worldwide, Dr. Roberto said the next step for the world of technology is into nanotechnology.

New Mars Forums

Announcement

#76 2003-04-23 00:13:06

Re: The economics of space elevators - Are they financially feasible?

#77 2003-04-23 01:32:47

Re: The economics of space elevators - Are they financially feasible?

#78 2003-04-23 09:22:14

Re: The economics of space elevators - Are they financially feasible?

#79 2003-04-23 09:26:38

Re: The economics of space elevators - Are they financially feasible?

#80 2003-04-23 09:48:48

Re: The economics of space elevators - Are they financially feasible?

#81 2003-04-23 09:53:36

Re: The economics of space elevators - Are they financially feasible?

#82 2003-04-23 10:10:03

Re: The economics of space elevators - Are they financially feasible?

#83 2003-04-23 10:20:14

Re: The economics of space elevators - Are they financially feasible?

#84 2003-04-23 10:22:21

Re: The economics of space elevators - Are they financially feasible?

#85 2003-04-23 10:27:22

Re: The economics of space elevators - Are they financially feasible?

#86 2003-04-23 10:29:36

Re: The economics of space elevators - Are they financially feasible?

#87 2003-04-23 10:40:21

Re: The economics of space elevators - Are they financially feasible?

#88 2003-04-23 11:08:52

Re: The economics of space elevators - Are they financially feasible?

#89 2003-04-23 11:17:05

Re: The economics of space elevators - Are they financially feasible?

#90 2003-04-23 11:21:54

Re: The economics of space elevators - Are they financially feasible?

#91 2003-04-23 12:29:10

Re: The economics of space elevators - Are they financially feasible?

#92 2003-04-23 12:32:14

Re: The economics of space elevators - Are they financially feasible?

#93 2003-04-23 12:33:50

Re: The economics of space elevators - Are they financially feasible?

#94 2003-04-23 13:14:55

Re: The economics of space elevators - Are they financially feasible?

#95 2003-04-23 13:24:53

Re: The economics of space elevators - Are they financially feasible?

#96 2003-04-23 13:27:07

Re: The economics of space elevators - Are they financially feasible?

#97 2003-04-23 13:31:31

Re: The economics of space elevators - Are they financially feasible?

#98 2003-04-23 13:39:08

Re: The economics of space elevators - Are they financially feasible?

#99 2003-04-23 13:58:01

Re: The economics of space elevators - Are they financially feasible?

#100 2003-04-23 14:02:45

Re: The economics of space elevators - Are they financially feasible?

Board footer