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I think anyone with some cash could haul up their own ribbon, unless we're into the "control" issue. Is that what you mean?

Um, by your own admission, you are talking about a large number of elevators competing. There is no competition on this road, or any other.

Roads are a flawed analogy - by their very nature there's no good way to have "competition". A more accurate comparison is the airlines or shipping lines that move cargo around the world today.

I'm not aware of any case where a government can run things more efficiently than a private sector.

In fact, in your analogy you would have so many elevators that chances are none of them would run at capacity, so the cars that do ride up would have to pay a larger chunk of the maintenance bill.

In other words, your "publicly run" scenario is inefficient and more expensive, like all other non-monopoly public works.

Well, more like businesses are always going to protect their profits at all costs.

Or... some people think the air force probably has a space plane, but they aren't sharing it for nat'l security reasons:

http://www.geocities.com/yoda448/area51/pdwe.html

Any search on "Doughnut on a rope contrail" or Pulse Detonation Wave Engine brings up quite a bit of Area-51 type conspiracy material.

So they can control it. What if the Chinese/Russians/whatever built one first? Then they'd own space. You get the idea.

"Canada... stand for". That's silly.

As far as sheets, it's no different than any other composite. Fiberglass is millions of fibers oriented in an expoxy. Graphite composites, again fibers in an expoxy.

Radiation shielding I doubt, but there is another nanotech breakthrough on this front: http://www.radshield.com/

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.

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."

I started putting together a spreedsheet based on numbers from the book here: http://perdue.net/spaceelev.xls

The cost I came up with was $253/kg for amortize, assuming 1-way disposable climbers. This is higher than my earlier estimate because the climber goes 200 km/hr, not 200 mi/hr, so it has less capacity. The $6 bln ribbon is less capacity, at 20 metric tons total, 13 metric tons net cargo capacity.

Anyway, I flipped further into the book and Ch 13 talks about the economics of the elevator.

They are claiming $1154/kg for the initial ribbon, depressurized cargo, 2-way trips, which is far higher than all my estimates.

They also suggest, as I mentioned earlier, you run a number of climbers up the ribbon before running them down. This is useful if you need return cargo, otherwise it should all be disposable climbers.

I said essentially it's a 50-man soyuz, at a bargain-basement price of ($20 mln/20 tons) of men and supplies = $500/pd.

Not to you. To maximize throughput of the ribbon, all climbers are going UP and ONLY UP the ribbon. To return, you DETACH from the ribbon and splash into the atmosphere, a la soyuz. To do this you need a heat shield and chemical thrusters (the lasers were for the traction climber, not thrusters).

Are we on the same page?

Now, we could re-think the 1-way climber strategy for manned capsules.

Since the manned capsule is so expensive, it may work out that it is best to do them all 2-way, so they climb back down the ribbon. They do not need a heat shield or thrusters (well, they might for safety reasons... if you get hung up on the ribbon, you could always detach and splash down) and if you climb back down the ribbon, the capsule is probably re-usable.

Still with me?

Now, do you understand why you want everything to go one-way? It takes 9 days up + 9 days down. That's 18 days PER TRIP instead of 1 1/2 days. There are strategies to make this better.

Then you probably won't go. Merely saying you won't pay for it doesn't make it so. The $100/pd figure is a guess anyway, and you must have at least enough for the entire duration of your trip, plus any emergency buffer.

Just because you don't follow what I've said from my very first post, doesn't mean it's weak.

This is from your first post:

First, this would require 110 tons/week, but you are only talking about 60 tons capacity. This is your own post here. Plus you did not include any weight for the climber itself.

Now, your number is ALMOST possible if you use all 1-way climbers, which I have talked about from the get-go. 1-way climbers can leave every 1 1/2 days.

But you are now claiming to be talking about TWO-WAY climbers, which makes your first post even further beyond possibility.

I have not done the math on that one. You haven't either apparently. Relatively simple physics I or Phy II math will let you calculate the amount of energy added to each pound to reach orbit. Figure the efficiency of the entire system and you can extrapolate the number of KW hours. Take that * $.07 to get the correct figure.

Why so emotional?

Are you saying you will send up all these crews without any hope of them returning and no hope of rescue if there is a failure in the ribbon or drive system?

No return? Forget the casino gamblers. Zero safety margin? Forget everyone else.

2 days? I guess, Soph, you don't even read the threads at all, so there's no point in talking with you. Perhaps you cannot follow what's happening.

It's 4.8 days to GEO and 9.6 days to the end of the ribbon. Are you saying you would want ZERO extra air, water, food, etc in case of emergency?

And what on earth will you eat when you reach your destination?

And all of that WEIGHS SOMETHING.

Please use your head. It's not merely the cost of air/food/water, it's the weight, at $XXX/pd.

I guess you are "blindly" in love with this ribbon idea. I am very interested in the ribbon, which is why I bought the book. However, I also have a head on my shoulders and can think rationally about it.

I haven't seen you try to rationalize the "more reasonable" $500/kg figure, given the numbers I worked out on maximum utilization. Bill and I have provided real calculations for amortization and utilization, perhaps you could do the same?

One thing I know for sure, the $100/kg is a fantasy. $30/kg is merely amortizing the $6 bln ribbon. It doesn't include the lifters, maintenance, staff, energy, etc. And it assume 100% utilization with zero breakdowns, zero mainenance on the ribbon and exact on-time launch 24x7 for 10 years straight.

As for "laser propulsion", if you mean ion propulsion or similar scheme, it's useless if you release at LEO. Again, you're nowhere near escape velocity (which is around 5 mi/sec). Simple math on this one. A chemical rocket would work of course.

Also a couple of you have mentioned going to LEO. The ribbon cannot deploy loads to LEO, as you have not achieved escape velocity.

If you were to let go of cargo at LEO, it would fall almost straight down and smack the atmosphere/earth very hard.

At  less-than-GEO, you can release cargo and have it in a highly-elliptical orbit. As you approach GEO, release of cargo would be virtually stationary.

You're interchanging kg and pounds. My numbers have been in pounds.