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Personally, I *LOVE* the elevator idea - yet Zubrin's hypersonic skyhook - catching Mach 20 scramjets with an orbiting tether may be a cheaper way to get people to LEO.
I stand firmly on my original point - HighLift needs to locate a solid source of "price is no object" users. In-elastic demand.
Tourism is a great bonus but cannot be the core. $25,000 for a few days in space, maybe I say YES --> but at $50,000 or $75,000 and my final answer might well be sorry, too expensive. . .
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If your costs are $250/kg, how is it $100,000 to lift a 90 kg person to orbit?
soph how much structure, supplies and equipment will be needed to safely lift a 200 pound man (me!) to LEO.
I weigh rather less than 100 kg so its $25,000 for my body. What about food, water, air, habitat, safety gear. If 25% is passenger and 75% is elevator cab, structural compenents and the like that adds up to $100,000, no?
Not really. An air filtration system using oxygen tanks that only has to function for one day at a time is not overly expensive, and no meal I know of costs $75,000.
My estimate would be about $5,000 of extra costs per person.
If air was that expensive for this duration of time, who would Scuba dive?
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Great, then it's about $45,000 per person, half of the $100,000 estimate.
You're interchanging kg and pounds. My numbers have been in pounds.
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Personally, I *LOVE* the elevator idea - yet Zubrin's hypersonic skyhook - catching Mach 20 scramjets with an orbiting tether may be a cheaper way to get people to LEO.
Scramjets don't exist, and how do you propose to catch something going Mach 20, and so much as slow it down? What if the thing misses?
Going at that speed, how would either the scramjet or the skyhook make it in one piece?
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Great, then it's about $45,000 per person, half of the $100,000 estimate.
You're interchanging kg and pounds. My numbers have been in pounds.
I know, a kg is equivalent to 2.2 pounds. So to estimate the cost, when the rate is $500/kg, you must convert 200 pounds to approximately 90-100 kg. 90 kg at a rate of $500/kg is $45,000 kg.
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I weigh rather less than 100 kg so its $25,000 for my body. What about food, water, air, habitat, safety gear. If 25% is passenger and 75% is elevator cab, structural compenents and the like that adds up to $100,000, no?
You're probably double-counting the weight of the elevator itself. The ribbon can lift 33 tons with a 50% safety margin. Max capacity is 66 tons.
So 13 tons of lifter + 20 tons cargo. Now the *cost* of the lifter, since it is disposable must be included in the cost of the 20 tons being lifted.
I'm back at the ~$500/pd figure * 20 tons.
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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.
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Also a couple of you have mentioned going to LEO. The ribbon cannot deploy loads to LEO, as you have not achieved escape velocity.
Does cab/hab - passenger ratios include radiation shielding for the van Allen belts?
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How long does the trip up take?
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I weigh rather less than 100 kg so its $25,000 for my body. What about food, water, air, habitat, safety gear. If 25% is passenger and 75% is elevator cab, structural compenents and the like that adds up to $100,000, no?
You're probably double-counting the weight of the elevator itself. The ribbon can lift 33 tons with a 50% safety margin. Max capacity is 66 tons.
So 13 tons of lifter + 20 tons cargo. Now the *cost* of the lifter, since it is disposable must be included in the cost of the 20 tons being lifted.
I'm back at the ~$500/pd figure * 20 tons.
The $500/lb estimate is double the more reasonable estimate of $500/kg. Highlift included the cost of the lifter when they made their $100/kg estimate, which we have gone from doubling, to quintupling, to multiplying by ten.
The elevator is also designed to release payload at appropriate speeds using its laser propulsion array.
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How long does the trip up take?
I think it is, what, 23,000 mi to GEO or GTO or whatever it is.
23,000/200 mph is 115 hours or 4.8 days. If you want to leave orbit, say going to mars, you have to go to the end of the ribbon at 2x that length. The last 1/2 of the trip you do not need laser power, as you are "falling" away from earth due to centrifugal force. You could probably also go faster than the 200 mph.
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The $500/lb estimate is double the more reasonable estimate of $500/kg. Highlift included the cost of the lifter when they made their $100/kg estimate, which we have gone from doubling, to quintupling, to multiplying by ten.
The elevator is also designed to release payload at appropriate speeds using its laser propulsion array.
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.
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Where has your ammortization been? clark pointed earlier toward the report to NASA, why don't you have a peek? My calculations are on the first page.
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.
No, beamed lasers are concentrated on photovoltaic panels to power the thrusters. This should have been described in Brad Edwards' book. Again, check the report to NASA.
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Thanks, Tim. . .
soph, remember you are working with a long series of best case scenarios. At some point your price/demand curve will see a cliff. Fall off that cliff and demand evaporates.
Listen, I want HighLift to build their elevator. Some critics want folks to fail, others point out flaws seeking to improve the planning so folks can be successful. I am the latter type of critic. . .
Wild optimism combined with bitter attacks on the "short sightedness" of opponents is one reason space advocates generate so little traction in the world at large. . .
That is all I am saying. . .
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Where has your ammortization been?
Look at the second page. As for what you posted on the first page, you are PAST the theoretical maximum capacity of the elevator, so it's impossible to achieve what you suggested.
No, beamed lasers are concentrated on photovoltaic panels to power the thrusters. This should have been described in Brad Edwards' book. Again, check the report to NASA.
Right, and electric propulsion tells you what? Very low power over a long time frame. Translation: you cannot launch into LEO or you will fall straight down and smack the atmosphere/earth. You CAN release somewhat below GEO and then use the thrusters to circularize your orbit. This would take months and it's not something that passengers are going to tolerate.
Cost breakdowns:
Amortize ribbon: $61/pd
Disposable Lifter: $500/pd (essentially a 50-man Soyuz w/heat shield and thrusters. Assuming huge cost benefits to mass-produce, I put this at $20 mln /each)
Energy: $100/pd
Supplies: $100/pd
We're already at $761/pd for manned capsules. It's the disposable capsule which must be able to maneuver and re-enter the atmosphere that really kills the cost ratio. Un-pressurised cargo should be really cheap though.
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Amortize ribbon: $61/pd
Disposable Lifter: $500/pd (essentially a 50-man Soyuz w/heat shield and thrusters. Assuming huge cost benefits to mass-produce, I put this at $20 mln /each)
Energy: $100/pd
Supplies: $100/pd
I don't know where to begin! $100/lb for lasers! Where can you be getting these figures?
$500/lb for a capsule that never has to come back down? Thrusters? The propulsion is coming from beamed energy, not rockets.
Who needs $100/lb of supplies? You mean to tell me that I need $13,500 of food, water, and clothing in the next two days? Don't be silly!
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I don't know where to begin! $100/lb for lasers! Where can you be getting these figures?
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.
$500/lb for a capsule that never has to come back down? Thrusters? The propulsion is coming from beamed energy, not rockets.
Who needs $100/lb of supplies? You mean to tell me that I need $13,500 of food, water, and clothing in the next two days? Don't be silly!
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.
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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.
Who's getting emotional?
If you'd actually read the book, you'd actually know how the concept works, like, for example, how the lasers function.
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?
Go ahead, break down to me how this costs $500/kg. And while your at it, explain why the heat shield has to be this powerful, when you are descending at subsonic speeds.
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?
I certainly wouldn't be willing to spend $60,000 per four day trip for food and water.
And what on earth will you eat when you reach your destination?
You are also assuming that all the mass aboard is people. You don't need much to sustain food for a week.
I can't read the thread? I've been more actively posting on this thread than you have.
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soph - I will look into this more and say more after some research.
But, please remember that your job (our job) is to persuade some really anal investment banker types not merely that the elevator will work but that there is essentially NO risk to the $10 billion you seek (or the $100 billion I say you will need).
Its called "due diligence" research and gets as nit picky and anal a "bean counting project" as can be imagined. But without it HighLift gets no money. None, nada, zilch.
Your job (our job) is to PROVE your numbers to a banker who is very skeptical about writing a $10 billion check.
Try going to Bank of America and saying "Dear banker, prove to me why why you shouldn't give me a loan. . ."
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If you'd actually read the book, you'd actually know how the concept works, like, for example, how the lasers function.
The lasers are for the traction engine to climb the ribbon. They do nothing to return to earth unless you climb back down the ribbon.
If you had paid even one IOTA of attention you would realize that we are talking about ONE WAY DISPOSABLE climbers. If you want 2-way climbers, you can skip the heat shield, but you cut the max cargo capacity, probably by 75%.
Go ahead, break down to me how this costs $500/kg.
This reached a new low, considering you already quoted my cost breakdown.
And while your at it, explain why the heat shield has to be this powerful, when you are descending at subsonic speeds.
AGAIN 1-way disposable climbers. 2-way climbers cut your capacity WAY down. Please follow along. Clearly you have not paid even 1 iota of attention from the get-go.
I certainly wouldn't be willing to spend $60,000 per four day trip for food and water.
In your last post you said $13,500, how did you move it to $60k?
You are also assuming that all the mass aboard is people. You don't need much to sustain food for a week.
Again, you didn't even read the last post I put up. MANNED capsules will be very expensive while de-pressurized cargo will be cheap.
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tim, I am asking you how you came to the conclusion that the capsule will cost $500/lb, let alone the other costs. Yes, I know you said the capsule will cost $500/lb, how did you get this number? Do I have to rephrase it so that you can understand?
If you had paid even one IOTA of attention you would realize that we are talking about ONE WAY DISPOSABLE climbers. If you want 2-way climbers, you can skip the heat shield, but you cut the max cargo capacity, probably by 75%.
Why would boosters going up need greater heat shields than boosters going up and down? This makes absolutely no sense.
In your last post you said $13,500, how did you move it to $60k?
Typo, I apologize. What I meant to say was I would not be willing to spend $3,500 a day in basic supplies. There is no reason for this type of expenditure.
Again, you didn't even read the last post I put up. MANNED capsules will be very expensive while de-pressurized cargo will be cheap.
I did read the last post. Once again, I will say it, the whole capsule will not be taken up by people only, there will be cargo on board as well, that doesn't need the same level of accomodation. You cannot calculate the entire cost of the capsule based on the needs of humans alone, which will not be the entirety of the payload.
AGAIN 1-way disposable climbers. 2-way climbers cut your capacity WAY down. Please follow along. Clearly you have not paid even 1 iota of attention from the get-go.
Would you stop posting insults that are invalid to begin with? You're trying to support your weak position by throwing out names.
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But, please remember that your job (our job) is to persuade some really anal investment banker types not merely that the elevator will work but that there is essentially NO risk to the $10 billion you seek (or the $100 billion I say you will need).
Yes, I know, a few months ago I wrote a business plan for a competition. I know how getting investment works.
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tim, I am asking you how you came to the conclusion that the capsule will cost $500/lb, let alone the other costs. Yes, I know you said the capsule will cost $500/lb, how did you get this number? Do I have to rephrase it so that you can understand?
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.
Why would boosters going up need greater heat shields than boosters going up and down? This makes absolutely no sense.
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.
Typo, I apologize. What I meant to say was I would not be willing to spend $3,500 a day in basic supplies. There is no reason for this type of expenditure.
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.
Would you stop posting insults that are invalid to begin with? You're trying to support your weak position by throwing out names.
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:
If 833,000 people a year went up, the costs would be covered. This is only 54,000 tonnes of "payload." The first Highlift elevator is designed for 30 tonnes a shot, at least twice a week.
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.
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tim: we could also attach a seond "down" ribbon to the anchor station, which the capsules transfer to to return to the surface of Earth.
So you still have a 5 day up/5 day down trip, and you get maximum traffic.
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tim: we could also attach a seond "down" ribbon to the anchor station, which the capsules transfer to to return to the surface of Earth.
Yep, if I had the cash laying around to build this, the very first thing I'd do (even before re-inforcing the first ribbon) would be to hoist up a redundant ribbon.
Given the lightning issue I mentioned earlier, and now the capacity issue, the redundant cable is a must-have.
The second cable DOES increase your cost/pound as far as amortization. Again, assuming maximum utilization of the up-cable, your amortization is now going to be > $61/pound. Probably like $80 or 90.
Plus if the cables were "near" each other, you could easily send up a second lifter and sort of "straddle" the first cable for a rescue attempt.
If you really needed to, you could send up a dual-climber that could haul up monster loads using both ribbons.
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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.
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