![]() | This page is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page. |
My yesterday's change to the economics section has been reverted by Rei. Please explain why or I will revert back .... Refrain from ad hominem attack, please. Paul Beardsell 17:18, 5 May 2004 (UTC)
Some people seem to be straining to reach the conclusion that something must somehow make space elevators impossible to operate. Before you do that, consider reading Edward's report: [1].
Is there something crucial in Edward's report that the Wikipedia article leaves out ?
Okay, I trimmed it down to only 62 k. I don't think I cut any live discussions, but you can check the page history, and copy & paste it back if necessary. -- wwoods 08:00, 8 May 2004 (UTC)
I wonder if it would be better to split this article into 2 or more parts somehow ? Perhaps a detailed economic exploration of a "simple" "basic version" (up-only, unmanned, etc.), and another page listing all kinds of variations and additions ("advanced version") and history. DavidCary 17:23, 11 May 2004 (UTC)
I agree with Paul Beardsell that we need to compare apples-to-apples; do we need 3 seperate economic analyses to compare
* satellite to LEO: rocket vs. elevator * satellite to GEO: rocket vs. elevator * human payload to LEO: rocket vs. elevator
? -- DavidCary 17:23, 11 May 2004 (UTC)
Yes, much better balanced. Thanks. What remains unclear is
Paul Beardsell 18:43, 4 May 2004 (UTC)
"vertical and tangential energy"
I put some numeric calculations dealing with
at http://c2.com/cgi/wiki?SpaceElevator .
Want me to move them here to wikipedia ? -- DavidCary
Why ? -- DavidCary 17:23, 11 May 2004 (UTC)
I agree with Paul Beardsell that "100% conversion efficiency" of the wireless power beam is unrealistic.
Perhaps it would be less controversial / more realistic to
at least until we get a better estimate of a "realistic" number.
Would it be crazy to stick with the Edwards report of up-only elevators in the economic analysis of a "basic elevator", then add these other nifty ideas and improvements in a later section (perhaps fore-shadowing with "Even neglecting other suggested improvements, this economic analysis shows ...") ?
Can we say the climbers use Beam-powered propulsion ?
It is unavoidable that it takes 57e6 N*m = 16 KWh of energy, per kilogram, to move any mass from the ground to geosynchronous orbit (allow me to call this "orbit energy"), no matter how you do it.
The overwhelming reason space elevators are (in theory) far less expensive than rockets is because
That's it.
Other reasons (such as
) are much less significant.
Edward's design has the "initial cable" has a mass of 19 800 kg, slightly less than a Russian geosynchronous communication satellite. At geosync, it's is strong enough to hold up the rest of the cable hanging "down" with a safety factor of 2.
(Should we discuss "running electricity up the cable" in an article -- rather than this talk page ?)
We must compare like with like. Rei's recent edit changing Bryan's figure of $100 to $1.74 is not valid because it is being compared with the actual rocket launch cost. As 0.5% is considered optmistic the correct figure must be at least 1.74*200 = $350/kg. Despite that this does not include capital costs and so is still understated in comparison to the rocket figure which includes at least some capital cost. I will change the figure accordingly. Paul Beardsell 02:33, 5 May 2004 (UTC)
Shuttle? Araine is $13000/kg (1993 figures) to LEO. To geostationary is $25000/kg (1999), the kid with the marbles reckons. (But if I am the kid with the marbles you are the one attempting to leave the boot marks in his face.) There are plans dating from 1993 which are a lot more feasible than the space elevator to reduce rocket LEO costs to $1300/kg. If the same factor applies then $2500/kg for geostationary. Capital cost inclusive and no major invention required. Compare that to the $2400/kg for 2.5million kg I have calculated for the basic $5bn elevator (and on which I invite criticism). Put that in your economics section. Paul Beardsell 16:44, 5 May 2004 (UTC)
(we're talking about [2], right ?)
Paul Beardsell 23:40, 5 May 2004 (UTC)
supplies some excellent links:
That gives us
The appropriate propellant mix (4 g LO2 + 1 g LH2, which eventually produce 5 g H2O) gives an average of
I think that's close enough for back-of-the envelope calculation; remind me to do more accurate calculations later. -- DavidCary
So that's 25 840 kg of LH2 * $3.60/kg =~= $ 93 000 worth of LH2, plus a bit more for the oxidizer, comes out to about what we calculated above.
Ooopsies, I forgot all about that. Anyone have dollar figures for that ?
Would you mind if I moved this discussion to [Ariane] ... or is there a page about the economics of rocket propellant in general ? Atlas launch costs, shuttle launch costs, [Space Shuttle program], Ariane launche costs, etc.)
Yes:
However, the space elevator is the "maximum cost efficiency per launch" method physically possible - and it *is* feasable if materials tech advances. Rei 17:40, 5 May 2004 (UTC)
Do you think that the sway will only be 200m? I just guessed a figure. But if the cable is 2m or 20m wide this is a tiny proportion of the length. The cable needs to be light and tension will have to be limited to limit the necessary strngth of the cable. How stiff will the cable be? If the sway is 2km and we want a 1km safety margin either side then it is a 4km swathe being cut through the sky. Space traffic control is going to be very difficult! And the sway could be 20km or more! A 22km swathe would surely be impossible to manage. Every low earth satellite would have to have its orbit adjusted every several hundred revolutions. Every second week!
And then, just as we have it all worked out, the weather forecasters force us to move the base 50km to avoid a storm. So we decide to build an untethered elevator instead but this destroys the economics: All the fuel wasted in rockets overcoming air resistance to get to the base station.
But once we are above the atmosphere rockets are no longer as inefficient and ion drives work: We can take the cable cars off their rails!
I know I'm going to be told I have added nothing knew - that all this is known. But what I am trying to illustrate is that each solution seems to make another problem worse.
Paul Beardsell 01:52, 5 May 2004 (UTC)
...
I am trying to moderate the Economics section of the article. Rei keeps on reverting my proposed change. I propose the following text. Essentially my changes are (i) a modification to the first paragraph to repair the misleading comparison of the full cost of rocket launches to the marginal cost assuming lossless transmission of energy of elevator lifting and (ii) a new paragraph which essentially points out that unless a helluva lot of mateial is transported the elevator cannot be justified on cost grounds. The proposed text
Economics
With space elevators like this, assuming a 0.5% energy conversion efficiency, materials can be sent into orbit at a fraction of the current costs. Total marginal cost is between $10,000 and $40,000 per rocket payload kg today and this compares to a marginal cost of $350 ($1.74 adjusted by the 0.5% efficiency factor) per space elevator transported kg. The marginal cost of a trip would consist solely of the electricity required to lift the elevator payload, some of which could be recovered by using descending elevators to generate electricity as they brake (suggested in some proposals), or generated by masses braking as they travel outward from geosynchronous orbit (a suggestion by Freeman Dyson in a private communication to Russell Johnston in the 1980s.) This means that hospitals, mining facilities, international trade, and travel could all be done in space with the help of these space elevators.
The efficiency of power transfer is a limiting issue. The most efficient power beaming in the present-day is a laser beaming system with photovoltaic panels on the climber optimized to the wavelength of the laser. With the best (and most expensive) current technology, between atmospheric losses, losses in generation of laser power, and losses in absorption on the panels, the efficiency is around 0.5%, the multiplier used above. And if climbers are to be disposable, the most expensive photovoltaic panels may not be an option.
Losses due to atmospheric spreading could be reduced by the use of adaptive optics, and losses due to absorption could be reduced by a properly chosen laser wavelength. But although laser and photovoltaic technologies have been rapidly advancing, it is unknown whether the losses can be reduced to an acceptable level. Barring significant development, costs will remain far higher than in the speculative optimal figures, and space elevator transports will be more expensive than current rocketry.
The cost of the power provided to the laser is also a limiting issue. While a land-based anchor point in most places can use power at the grid rate, this is not an option for a mobile oceangoing platform.
Up-only climber designs must replace each climber in its entirety or carry up enough fuel to get it out of orbit - a potentially costly venture.
When comparing the costs of the space elevator with conventional rockets it is important to take capital costs into account. Whereas the cost per kilogram to place 1kg in geostationary orbit using Ariane 5 is about $25,000 this does include much of the capital cost: The cost of fuel being but a tiny percentage of that, less than $30/kg. The energy cost of the space elevator is perhaps $350/kg, if a 0.5% transmission efficiency is taken into account. With the lowest estimate of capital cost of around $5bn for the simplest space elevator, the elevator requires a substantial payload to be transported before it would become cheaper than rockets. The next generation of Ariane rocket can lift twice the payload, requiring perhaps twice the fuel, but other costs are unlikely to double. It is speculated by some, possibly naively, that future technological and efficiency advances, coupled with a demand to shift into geostationary orbit the amount of material which would justify a space elevator, could reduce rocket costs substantially, making the task of justifying the elevator on cost grounds somewhat more onerous.
OK, what's wrong with that? Rei says the fuel cost is out but if so it is not out enough to ruin the argument. Paul Beardsell 22:42, 6 May 2004 (UTC)
OK, anything which isn't a whitewash of the costs is fine with me. The problem with the costs of space transport is that the costs are often at least partly hidden in defence budgets - the accounts are not transparent. Another problem (from an economics perspective) is that some people so much want to do the space exploration that the huge cost is played down by them. Similarly, the science/exploration/adventure/survival "right stuff" aspect almost makes cost a non-issue, from time to time. And, of course, the benefits of space travel, even if they are substantial, are often intangible and difficult to measure. However, there is an economics section in the article and that section must be seen to deal honestly with the costs.
I think my use of the term capital cost was unhelpful or it was misunderstood here. I do not know how transparent the Ariane accounting is, but the charge per kg lifted is $25,000. My estimate of the fuel cost per kilogram lifted, (for LH2+LO2, admittedly, and even if it was out by a factor of 10, which it wasn't) at $15 per lifted kg (doubled in my proposed edit of the economics section, above) certainly shows that Ariane customers are paying for a lot more than just fuel: They are paying extra presumably to contribute to or to cover the manufacturing cost of the essentially disposable rocket, staffing costs, the cost of preparing the launch, cost of maintaining the launch site etc. This $25,000/kg figure rocket figure is used in the first paragraph of the economics section in comparison to the $1.74/kg figure for the idealised electricity usage of the elevator. As I have tiresomely demonstrated, this is a misleading comparison. There is the cost of building the elevator which is not factored into the 1.74 figure whereas the cost of the rocket is factored into the $25,000 figure. Essentially the issue is one of marginal cost vs total cost. For the rocket it is the same total cost per kg, more or less, no matter how much we lift. For the elevator we need to lift a lot before the total costs fall below the rocket. Why this obvious point is resisted I do not know. The economics section, as it stands, reeks of bias.
Before a reply, if any, is crafted, please take a second to read what I have written. Responses have put words in my mouth. Please note that yet again I have not mentioned the word "shuttle".
Paul Beardsell 11:45, 7 May 2004 (UTC)
( Beardsell correctly calculates the density of LH2, someone claims his LH2 calculations are "way off", Beardsell gets upset. I think I would too. Focus on getting the correct numbers in the article, people. I don't care who was "right" and who was "wrong". -- DavidCary 17:23, 11 May 2004 (UTC) )
(...discussion about incompetence and insanity snipped...)
I found this but would be interested to see any other reference. Paul Beardsell 18:25, 7 May 2004 (UTC)
This is something that applies to every talk page, not just the space elevator talk page. Could we take this to
? -- DavidCary 17:23, 11 May 2004 (UTC)
...
Shuttle? How many times must I say that is what it costs on Ariane V all in! That is what it costs to put your pet science project on the rocket. Paul Beardsell
It's 2054 and the Namibian Telecommunications Agency senior civil servants have been reading Wikipedia. They persuade the Minister of Telecommunications that the NTA now needs to launch its own 1000kg satellite. For arcane budgeting reasons they would like the quote in 2004 US$. They first approach the ESA who explain that cost savings have unfortunately not been possible since 2004 so the price is the same in 2054, expressed in 2004 US$, as it was back in 2004. The NTA says stop mucking about, how much? $25million. The NTA gulped and hurried away.
How much to use the Space Elevator, they ask NASA? The answer was confidentional but was significantly above the $1,740 budget. But how much more?
Paul Beardsell 20:44, 7 May 2004 (UTC)
AutoCAD Rocketry (very) Limited got its dubious tender under the door just before midnight: $2.5million. Paul Beardsell 20:55, 7 May 2004 (UTC)
Y'know, I will try very hard (but I will fail) not to say "I told you so" when someone comes up with some more authoritative source for reducing rocketing costs. Paul Beardsell 23:55, 7 May 2004 (UTC)
As I suspected (and as you all knew) it seems that the economic justification of the space elevator depends on lifting a whole lot more stuff into orbit than we currently do. If all we want to do is to have GPS (and the new Euro equivalent) and telecoms and weather forecasting and infra red astronomy and the occasional probe to the rings of Saturn then the financial justification of the elevator is difficult.
So, what is the elevator for?
Can we not remind ourselves that the solar system has no other planet which is habitable on economic grounds. That no nearby star has a habitable planet. That we could do a lot with US$40bn other than build an elevator.
Paul Beardsell 23:55, 7 May 2004 (UTC)
And I thought I (or we) had annoyed you into staying away. Recently I have wanted to reflect in the article that in order to justify the elevator that we must want lift a whole lot more mass than we do. I have been frustrated in that. Paul Beardsell 00:23, 8 May 2004 (UTC)
I dispute that any reading of the current version of the Economics section allows it NPOV status. My issues are
Paul Beardsell 18:11, 10 May 2004 (UTC)
Once again you put words in my mouth: I did not say it's just fuel costs. I acknowledged, if you read what I wrote with the slightest care, there are other costs. But you make unsupported assertions. Feel free to do the maths for the Ariane. Surely it is the intellectual duty of they who assert the elevator is cheaper to properly back up their assertions. I did not introduce the Economics section here. But if it is here it must be NPOV. Oh, and as I have to say every time: I have not said anything about the Shuttle costs. Paul Beardsell 19:29, 10 May 2004 (UTC)
![]() | This page is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page. |
My yesterday's change to the economics section has been reverted by Rei. Please explain why or I will revert back .... Refrain from ad hominem attack, please. Paul Beardsell 17:18, 5 May 2004 (UTC)
Some people seem to be straining to reach the conclusion that something must somehow make space elevators impossible to operate. Before you do that, consider reading Edward's report: [1].
Is there something crucial in Edward's report that the Wikipedia article leaves out ?
Okay, I trimmed it down to only 62 k. I don't think I cut any live discussions, but you can check the page history, and copy & paste it back if necessary. -- wwoods 08:00, 8 May 2004 (UTC)
I wonder if it would be better to split this article into 2 or more parts somehow ? Perhaps a detailed economic exploration of a "simple" "basic version" (up-only, unmanned, etc.), and another page listing all kinds of variations and additions ("advanced version") and history. DavidCary 17:23, 11 May 2004 (UTC)
I agree with Paul Beardsell that we need to compare apples-to-apples; do we need 3 seperate economic analyses to compare
* satellite to LEO: rocket vs. elevator * satellite to GEO: rocket vs. elevator * human payload to LEO: rocket vs. elevator
? -- DavidCary 17:23, 11 May 2004 (UTC)
Yes, much better balanced. Thanks. What remains unclear is
Paul Beardsell 18:43, 4 May 2004 (UTC)
"vertical and tangential energy"
I put some numeric calculations dealing with
at http://c2.com/cgi/wiki?SpaceElevator .
Want me to move them here to wikipedia ? -- DavidCary
Why ? -- DavidCary 17:23, 11 May 2004 (UTC)
I agree with Paul Beardsell that "100% conversion efficiency" of the wireless power beam is unrealistic.
Perhaps it would be less controversial / more realistic to
at least until we get a better estimate of a "realistic" number.
Would it be crazy to stick with the Edwards report of up-only elevators in the economic analysis of a "basic elevator", then add these other nifty ideas and improvements in a later section (perhaps fore-shadowing with "Even neglecting other suggested improvements, this economic analysis shows ...") ?
Can we say the climbers use Beam-powered propulsion ?
It is unavoidable that it takes 57e6 N*m = 16 KWh of energy, per kilogram, to move any mass from the ground to geosynchronous orbit (allow me to call this "orbit energy"), no matter how you do it.
The overwhelming reason space elevators are (in theory) far less expensive than rockets is because
That's it.
Other reasons (such as
) are much less significant.
Edward's design has the "initial cable" has a mass of 19 800 kg, slightly less than a Russian geosynchronous communication satellite. At geosync, it's is strong enough to hold up the rest of the cable hanging "down" with a safety factor of 2.
(Should we discuss "running electricity up the cable" in an article -- rather than this talk page ?)
We must compare like with like. Rei's recent edit changing Bryan's figure of $100 to $1.74 is not valid because it is being compared with the actual rocket launch cost. As 0.5% is considered optmistic the correct figure must be at least 1.74*200 = $350/kg. Despite that this does not include capital costs and so is still understated in comparison to the rocket figure which includes at least some capital cost. I will change the figure accordingly. Paul Beardsell 02:33, 5 May 2004 (UTC)
Shuttle? Araine is $13000/kg (1993 figures) to LEO. To geostationary is $25000/kg (1999), the kid with the marbles reckons. (But if I am the kid with the marbles you are the one attempting to leave the boot marks in his face.) There are plans dating from 1993 which are a lot more feasible than the space elevator to reduce rocket LEO costs to $1300/kg. If the same factor applies then $2500/kg for geostationary. Capital cost inclusive and no major invention required. Compare that to the $2400/kg for 2.5million kg I have calculated for the basic $5bn elevator (and on which I invite criticism). Put that in your economics section. Paul Beardsell 16:44, 5 May 2004 (UTC)
(we're talking about [2], right ?)
Paul Beardsell 23:40, 5 May 2004 (UTC)
supplies some excellent links:
That gives us
The appropriate propellant mix (4 g LO2 + 1 g LH2, which eventually produce 5 g H2O) gives an average of
I think that's close enough for back-of-the envelope calculation; remind me to do more accurate calculations later. -- DavidCary
So that's 25 840 kg of LH2 * $3.60/kg =~= $ 93 000 worth of LH2, plus a bit more for the oxidizer, comes out to about what we calculated above.
Ooopsies, I forgot all about that. Anyone have dollar figures for that ?
Would you mind if I moved this discussion to [Ariane] ... or is there a page about the economics of rocket propellant in general ? Atlas launch costs, shuttle launch costs, [Space Shuttle program], Ariane launche costs, etc.)
Yes:
However, the space elevator is the "maximum cost efficiency per launch" method physically possible - and it *is* feasable if materials tech advances. Rei 17:40, 5 May 2004 (UTC)
Do you think that the sway will only be 200m? I just guessed a figure. But if the cable is 2m or 20m wide this is a tiny proportion of the length. The cable needs to be light and tension will have to be limited to limit the necessary strngth of the cable. How stiff will the cable be? If the sway is 2km and we want a 1km safety margin either side then it is a 4km swathe being cut through the sky. Space traffic control is going to be very difficult! And the sway could be 20km or more! A 22km swathe would surely be impossible to manage. Every low earth satellite would have to have its orbit adjusted every several hundred revolutions. Every second week!
And then, just as we have it all worked out, the weather forecasters force us to move the base 50km to avoid a storm. So we decide to build an untethered elevator instead but this destroys the economics: All the fuel wasted in rockets overcoming air resistance to get to the base station.
But once we are above the atmosphere rockets are no longer as inefficient and ion drives work: We can take the cable cars off their rails!
I know I'm going to be told I have added nothing knew - that all this is known. But what I am trying to illustrate is that each solution seems to make another problem worse.
Paul Beardsell 01:52, 5 May 2004 (UTC)
...
I am trying to moderate the Economics section of the article. Rei keeps on reverting my proposed change. I propose the following text. Essentially my changes are (i) a modification to the first paragraph to repair the misleading comparison of the full cost of rocket launches to the marginal cost assuming lossless transmission of energy of elevator lifting and (ii) a new paragraph which essentially points out that unless a helluva lot of mateial is transported the elevator cannot be justified on cost grounds. The proposed text
Economics
With space elevators like this, assuming a 0.5% energy conversion efficiency, materials can be sent into orbit at a fraction of the current costs. Total marginal cost is between $10,000 and $40,000 per rocket payload kg today and this compares to a marginal cost of $350 ($1.74 adjusted by the 0.5% efficiency factor) per space elevator transported kg. The marginal cost of a trip would consist solely of the electricity required to lift the elevator payload, some of which could be recovered by using descending elevators to generate electricity as they brake (suggested in some proposals), or generated by masses braking as they travel outward from geosynchronous orbit (a suggestion by Freeman Dyson in a private communication to Russell Johnston in the 1980s.) This means that hospitals, mining facilities, international trade, and travel could all be done in space with the help of these space elevators.
The efficiency of power transfer is a limiting issue. The most efficient power beaming in the present-day is a laser beaming system with photovoltaic panels on the climber optimized to the wavelength of the laser. With the best (and most expensive) current technology, between atmospheric losses, losses in generation of laser power, and losses in absorption on the panels, the efficiency is around 0.5%, the multiplier used above. And if climbers are to be disposable, the most expensive photovoltaic panels may not be an option.
Losses due to atmospheric spreading could be reduced by the use of adaptive optics, and losses due to absorption could be reduced by a properly chosen laser wavelength. But although laser and photovoltaic technologies have been rapidly advancing, it is unknown whether the losses can be reduced to an acceptable level. Barring significant development, costs will remain far higher than in the speculative optimal figures, and space elevator transports will be more expensive than current rocketry.
The cost of the power provided to the laser is also a limiting issue. While a land-based anchor point in most places can use power at the grid rate, this is not an option for a mobile oceangoing platform.
Up-only climber designs must replace each climber in its entirety or carry up enough fuel to get it out of orbit - a potentially costly venture.
When comparing the costs of the space elevator with conventional rockets it is important to take capital costs into account. Whereas the cost per kilogram to place 1kg in geostationary orbit using Ariane 5 is about $25,000 this does include much of the capital cost: The cost of fuel being but a tiny percentage of that, less than $30/kg. The energy cost of the space elevator is perhaps $350/kg, if a 0.5% transmission efficiency is taken into account. With the lowest estimate of capital cost of around $5bn for the simplest space elevator, the elevator requires a substantial payload to be transported before it would become cheaper than rockets. The next generation of Ariane rocket can lift twice the payload, requiring perhaps twice the fuel, but other costs are unlikely to double. It is speculated by some, possibly naively, that future technological and efficiency advances, coupled with a demand to shift into geostationary orbit the amount of material which would justify a space elevator, could reduce rocket costs substantially, making the task of justifying the elevator on cost grounds somewhat more onerous.
OK, what's wrong with that? Rei says the fuel cost is out but if so it is not out enough to ruin the argument. Paul Beardsell 22:42, 6 May 2004 (UTC)
OK, anything which isn't a whitewash of the costs is fine with me. The problem with the costs of space transport is that the costs are often at least partly hidden in defence budgets - the accounts are not transparent. Another problem (from an economics perspective) is that some people so much want to do the space exploration that the huge cost is played down by them. Similarly, the science/exploration/adventure/survival "right stuff" aspect almost makes cost a non-issue, from time to time. And, of course, the benefits of space travel, even if they are substantial, are often intangible and difficult to measure. However, there is an economics section in the article and that section must be seen to deal honestly with the costs.
I think my use of the term capital cost was unhelpful or it was misunderstood here. I do not know how transparent the Ariane accounting is, but the charge per kg lifted is $25,000. My estimate of the fuel cost per kilogram lifted, (for LH2+LO2, admittedly, and even if it was out by a factor of 10, which it wasn't) at $15 per lifted kg (doubled in my proposed edit of the economics section, above) certainly shows that Ariane customers are paying for a lot more than just fuel: They are paying extra presumably to contribute to or to cover the manufacturing cost of the essentially disposable rocket, staffing costs, the cost of preparing the launch, cost of maintaining the launch site etc. This $25,000/kg figure rocket figure is used in the first paragraph of the economics section in comparison to the $1.74/kg figure for the idealised electricity usage of the elevator. As I have tiresomely demonstrated, this is a misleading comparison. There is the cost of building the elevator which is not factored into the 1.74 figure whereas the cost of the rocket is factored into the $25,000 figure. Essentially the issue is one of marginal cost vs total cost. For the rocket it is the same total cost per kg, more or less, no matter how much we lift. For the elevator we need to lift a lot before the total costs fall below the rocket. Why this obvious point is resisted I do not know. The economics section, as it stands, reeks of bias.
Before a reply, if any, is crafted, please take a second to read what I have written. Responses have put words in my mouth. Please note that yet again I have not mentioned the word "shuttle".
Paul Beardsell 11:45, 7 May 2004 (UTC)
( Beardsell correctly calculates the density of LH2, someone claims his LH2 calculations are "way off", Beardsell gets upset. I think I would too. Focus on getting the correct numbers in the article, people. I don't care who was "right" and who was "wrong". -- DavidCary 17:23, 11 May 2004 (UTC) )
(...discussion about incompetence and insanity snipped...)
I found this but would be interested to see any other reference. Paul Beardsell 18:25, 7 May 2004 (UTC)
This is something that applies to every talk page, not just the space elevator talk page. Could we take this to
? -- DavidCary 17:23, 11 May 2004 (UTC)
...
Shuttle? How many times must I say that is what it costs on Ariane V all in! That is what it costs to put your pet science project on the rocket. Paul Beardsell
It's 2054 and the Namibian Telecommunications Agency senior civil servants have been reading Wikipedia. They persuade the Minister of Telecommunications that the NTA now needs to launch its own 1000kg satellite. For arcane budgeting reasons they would like the quote in 2004 US$. They first approach the ESA who explain that cost savings have unfortunately not been possible since 2004 so the price is the same in 2054, expressed in 2004 US$, as it was back in 2004. The NTA says stop mucking about, how much? $25million. The NTA gulped and hurried away.
How much to use the Space Elevator, they ask NASA? The answer was confidentional but was significantly above the $1,740 budget. But how much more?
Paul Beardsell 20:44, 7 May 2004 (UTC)
AutoCAD Rocketry (very) Limited got its dubious tender under the door just before midnight: $2.5million. Paul Beardsell 20:55, 7 May 2004 (UTC)
Y'know, I will try very hard (but I will fail) not to say "I told you so" when someone comes up with some more authoritative source for reducing rocketing costs. Paul Beardsell 23:55, 7 May 2004 (UTC)
As I suspected (and as you all knew) it seems that the economic justification of the space elevator depends on lifting a whole lot more stuff into orbit than we currently do. If all we want to do is to have GPS (and the new Euro equivalent) and telecoms and weather forecasting and infra red astronomy and the occasional probe to the rings of Saturn then the financial justification of the elevator is difficult.
So, what is the elevator for?
Can we not remind ourselves that the solar system has no other planet which is habitable on economic grounds. That no nearby star has a habitable planet. That we could do a lot with US$40bn other than build an elevator.
Paul Beardsell 23:55, 7 May 2004 (UTC)
And I thought I (or we) had annoyed you into staying away. Recently I have wanted to reflect in the article that in order to justify the elevator that we must want lift a whole lot more mass than we do. I have been frustrated in that. Paul Beardsell 00:23, 8 May 2004 (UTC)
I dispute that any reading of the current version of the Economics section allows it NPOV status. My issues are
Paul Beardsell 18:11, 10 May 2004 (UTC)
Once again you put words in my mouth: I did not say it's just fuel costs. I acknowledged, if you read what I wrote with the slightest care, there are other costs. But you make unsupported assertions. Feel free to do the maths for the Ariane. Surely it is the intellectual duty of they who assert the elevator is cheaper to properly back up their assertions. I did not introduce the Economics section here. But if it is here it must be NPOV. Oh, and as I have to say every time: I have not said anything about the Shuttle costs. Paul Beardsell 19:29, 10 May 2004 (UTC)