The Idea of A Space Fortress

[Formless]

Solar power stations can get that sunlight 24 hours a day, aren't inhibited by little things like the weather, and help us get a foot in the door for space colonization. There's three advantages it has over terrestrial solar power that I thought of in less than 30 seconds. Is it really that hard for you to see beyond your preconceptions?

[Zaune]

Solar power stations can get that sunlight 24 hours a day, aren't inhibited by little things like the weather, and help us get a foot in the door for space colonization. There's three advantages it has over terrestrial solar power that I thought of in less than 30 seconds. Is it really that hard for you to see beyond your preconceptions?

But do those advantages really justify the not-inconsiderable logistical problems? Quite apart from the staggering expense of building the things in the first place, the only way of returning the collected power to the planet's surface is by firing microwave radiation or reflected IR at a collector dish. That's not especially energy-efficient (see the thread on lasers on the first page), and it demands a quite small circular error probability. Not exactly compliant with the spirit of the Outer Space Treaty either.

[Singular Intellect]

Solar power stations can get that sunlight 24 hours a day,

We don't need access to solar input 24 hours a day. All we need is efficient and effective means of both collecting and storing the huge amounts of excess energy we can capture during sunlight hours, which are already being rapidly developed.

aren't inhibited by little things like the weather,

Presumably you've bought into the myth of zero solar power production on overcast days, are unaware of thermal/infrared solar power generation technologies and are grossly underestimating the amount of available solar power compared to our energy needs.

and help us get a foot in the door for space colonization.

Irelevant when I'm talking about simple energy consumption for our societies. Resources devoted to space exploration and colonization are increased when not burdened by having to deploy and maintain energy production facilities which are much more easily deployed and maintained on our planetary surface.

There's three advantages it has over terrestrial solar power that I thought of in less than 30 seconds. Is it really that hard for you to see beyond your preconceptions?

You're subscribing to overly costly and time consuming satellite projects when much better options are available, like solar power plant islands.

Never mind the ridiculous logistics problems of space based solar power generation, when it's vastly cheaper and more practical to integrate solar power generation technologies into our existing planetary based infrastructures.

[Formless]

But do those advantages really justify the not-inconsiderable logistical problems?

The space colonization one certainly does. There are many, many long term reasons to invest in space technology, and those logistical problems are not going away any time soon. However, in the short run there aren't very many incentives to make people care. This can make people care.

Quite apart from the staggering expense of building the things in the first place, the only way of returning the collected power to the planet's surface is by firing microwave radiation or reflected IR at a collector dish. That's not especially energy-efficient (see the thread on lasers on the first page), and it demands a quite small circular error probability.

But on the other hand, the energy comes in a form that isn't hindered by clouds of all things. Yeah, its no cure all, but simply dismissing it because "we get tons of sunlight right where we are" is ignoring some serious practicality problems with the existing technology.

Not exactly compliant with the spirit of the Outer Space Treaty either.

No, this has been addressed basically every time this subject comes up. Just because you are beaming energy to the ground does not mean that its a death ray. Most of the actual proposals that have been made (the Japanese were seriously looking into it last I heard) involve a microwave beam with no more intensity than the microwaves coming from your average cell phone tower.

Furthermore, the Outer Space Treaty only bans nations from placing WMDs in space or from putting military bases on celestial bodies. It would be perfectly legal to put a laser kill sat or kinetic impactors into orbit. Just not nukes, and not on the moon.

[Formless]

We don't need access to solar input 24 hours a day. All we need is efficient and effective means of both collecting and storing the huge amounts of excess energy we can capture during sunlight hours, which are already being rapidly developed.

Well we don't have that, now do we halfwit? And don't try that "but we're working on it" excuse on me. Appealing to technology that does not yet exist is handwaving.

Presumably you've bought into the myth of zero solar power production on overcast days, are unaware of thermal/infrared solar power generation technologies and are grossly underestimating the amount of available solar power compared to our energy needs.

Evidence please on the claim that we can get useful energy from infrared wavelengths. USEFUL energy, not heat, mind you. You can call something a myth, but can you put your money where your enormous mouth is?

Irelevant when I'm talking about simple energy consumption for our societies. Resources devoted to space exploration and colonization are increased when not burdened by having to deploy and maintain energy production facilities which are much more easily deployed and maintained on our planetary surface.

Now you are arbitrarily limiting the definition of an advantage to suit your preconceptions. I'm not impressed. Also, please show how it would be all that much of a burden. I'm not wasting time on someone who throws out talking points without showing their work.

You're subscribing to overly costly and time consuming satellite projects when much better options are available, like solar power plant islands.

Oh, yay, put more shit into the ocean! Yeah, like, the oceans never have bad weather that could simply capsize your fantasy islands (without even talking about the atmosphere absorbing energy, it still ruins your argument). How do you propose we keep these stations afloat? How do you propose they be installed (since you love pointing out the obvious logistic hurdles of space technology)? How do you propose that energy be transported back to the population centers they are supposed to be supplying? And what about people living in landlocked states like myself (I'm in Colorado)? Are we supposed to just go fuck ourselves? And lastly, what about the ecosystem? Its not like plankton and other wildlife have to live in those oceans or anything.

Dumbass.

Never mind the ridiculous logistics problems of space based solar power generation, when it's vastly cheaper and more practical to integrate solar power generation technologies into our existing planetary based infrastructures.

No numbers, no argument. Put up or shut up, fool.

[Singular Intellect]

We don't need access to solar input 24 hours a day. All we need is efficient and effective means of both collecting and storing the huge amounts of excess energy we can capture during sunlight hours, which are already being rapidly developed.

Well we don't have that, now do we halfwit? And don't try that "but we're working on it" excuse on me. Appealing to technology that does not yet exist is handwaving.

You mean technology like:

Infrared energy conversion?
PETE Technology?
Greater solar panel efficiency?
Storage technology?
What? Another solar power breakthrough?
Greater efficiency? Significantly reduced cost?
Even greater efficiency?
Self cleaning solar panels?
More cheap inventions of solar?

Please, elaborate, what breakthroughs and technology do you consider sufficiently convincing?

Presumably you've bought into the myth of zero solar power production on overcast days, are unaware of thermal/infrared solar power generation technologies and are grossly underestimating the amount of available solar power compared to our energy needs.

Evidence please on the claim that we can get useful energy from infrared wavelengths. USEFUL energy, not heat, mind you. You can call something a myth, but can you put your money where your enormous mouth is?

See above. Ballpark figures are our planet receives ten thousand times more energy than our entire civilization consumes, we need to only tap a tiny fraction of it to meet all our energy needs.

Irelevant when I'm talking about simple energy consumption for our societies. Resources devoted to space exploration and colonization are increased when not burdened by having to deploy and maintain energy production facilities which are much more easily deployed and maintained on our planetary surface.

Now you are arbitrarily limiting the definition of an advantage to suit your preconceptions. I'm not impressed. Also, please show how it would be all that much of a burden. I'm not wasting time on someone who throws out talking points without showing their work.

You think carrying payloads, delivering upgrades, simple maintenance and logistics in orbit has any kind of cost effectiveness or practicality compared to doing so on dry land and the ocean? What the fuck are you smoking?

Oh, yay, put more shit into the ocean! Yeah, like, the oceans never have bad weather that could simply capsize your fantasy islands

They're not fantasy. They're being built as we speak, you ignorant simpleton.

Futhermore, it would be vastly easier to repair and maintain systems on dry land and the nearby ocean than in fucking orbit. Or do you think space based solar plants with necessarily large surface areas would be immune to significant problems like space debris?

(without even talking about the atmosphere absorbing energy, it still ruins your argument).

See my previous link on energy input from the sun hitting the surface of our planet. We have more than what we know what to do with.

How do you propose we keep these stations afloat?

Yeah, too bad we haven't figured out how to make shit float yet.

How do you propose they be installed (since you love pointing out the obvious logistic hurdles of space technology)?

Yeah, beause our capability to implement infrastructure in space even remotely compares to doing so on land or the ocean, right?

How do you propose that energy be transported back to the population centers they are supposed to be supplying?

Solar power is a decentralized energy source. You don't need to live near the ocean. Anywhere you see the sun will do just fine.

And what about people living in landlocked states like myself (I'm in Colorado)?

You guys don't get sunshine? That's news to me.

Seriously though, this is one of the stupidest fucking questions I've ever seen regarding solar power.

Are we supposed to just go fuck ourselves? And lastly, what about the ecosystem? Its not like plankton and other wildlife have to live in those oceans or anything.

Yeah, utterly insignificant portions of the ocean having artificial islands floating on it would be so disruptive! Especially since all they are doing is collecting that damn polluting sunlight!

I'm the dumbass, eh?

[someone_else]

Meh, I'd just like to point out that Earth is round (build power stations on both sides duh!) and that with the cost of developing and launching any kind of decent-sized SSPs with any chance of making a profit in your granchildren's lifetime, you can build a buttload of solar power stations on Earth.

And not only of the solar-electrical kind (less effective), but of the solar-thermal kind (more effective). That is if you stupidly insist to use solar only even when there are other sources. Water turbines driven by tides or currents work fine too.

And anyway, putting cables to move the energy around for everyone isn't horribly complex as making a SSP, let alone a Space Fortress to defend them from brown people that want your energy.

[Sarevok]

Solar power from space is only questionable if you are launching the panels from Earth. If you are manufacturing photovoltaic panels from lunar or asteroid based resources then they are quite competitive. More importantly they have virtually unlimited growth potential.

Remember with SSP you have the entire solar system to play with ! Think big not small.

[eion]

All this diversion on orbital vs. terrestrial solar power fails to add anything to the discussion of the advantages and disadvantages of an asteroid-based orbital fortress. There are other uses for such a fortress besides defending satellites.

A single asteroid-fortress would have to be attacked by dozens of warships to even the odds, for instance.

The OP was about the uses and potential of building a space fortress, not about solar power.

[Eleas]

All this diversion on orbital vs. terrestrial solar power fails to add anything to the discussion of the advantages and disadvantages of an asteroid-based orbital fortress. There are other uses for such a fortress besides defending satellites.

A single asteroid-fortress would have to be attacked by dozens of warships to even the odds, for instance.

The OP was about the uses and potential of building a space fortress, not about solar power.

I'm curious. What's a "warship"?

[Formless]

Please, elaborate, what breakthroughs and technology do you consider sufficiently convincing?

First of all, only one of those had to do with energy storage, and the article was from 2008. Where is this so called green energy revolution promised three years ago? What you don't understand is that cutting edge technology rarely pans out. How many times have hydrogen fuel cells come up, promising so much but never delivering? Sorry to burst the bubble you've been living in, but they were a fad. Its the technologies that are cost effective and proven through actual use in the field that make societies change. I've heard a lot of things from pop-science rags promising this that and the other with regards to solar, wind, nuclear, and other technologies green and otherwise futuristic, and how many of them pan out? Precious few. Hence, any discussion has to be about technologies we know work or will work, not technologies that are still in beta at best. While there are certainly issues to be resolved with power stations in space, they are not nearly as reliant on stuff that still needs work in the lab. Hence, the only thing really in the way is the logistics, and so far you haven't actually shown why that should sway our hands.

So in answer to your question, what would be convincing would be things that aren't reliant upon promises of some green revolution that's always another five to ten years away, but which we never achieve, made by people in desperate need of a grant.

See above. Ballpark figures are our planet receives ten thousand times more energy than our entire civilization consumes, we need to only tap a tiny fraction of it to meet all our energy needs.

You are a fucking broken record. I don't care how much energy hits the earth, what matters is how much of it actually can be converted into usable energy in a consistent manner. If cloud cover can shut off the power grid right during peak hours, people will still rely on good old fashioned coal fired plants and the green revolution is doomed. (At least, assuming nuclear never gets back its old prestige, which I do doubt it ever will)

Now to deal with the links that had to do with infrared reception. Once again, quotes like these:

The breakthrough has led theorists to predict that plastic solar cells could one day become five times more efficient than current solar cell technology.

do not impress me, especially when the article was from 2005. The PETE links from 2010 is better, but still is about technology that is the cutting edge, and thus has yet to prove its cost efficiency or the kind of reliability needed to actually be revolutionary. The 2006 link about photo-responsive alloys is interesting, but mostly for its intellectual stimulation. Once again, no data on whether or not it will be economic enough to make waves. plus, I would like to know what the production requirements are. Its not green if it makes shittons of pollutants.

Are you seeing a pattern yet? New technology cannot be a factor in this discussion, precisely because its new and unproven.

The rest of those articles are only about improving the efficiency of existing solar panels, and while more like what excites me, do not sway this debate because they could just as easily improve solar power collection in space.

More in a couple hours, I have to go now.

[Sarevok]

All this diversion on orbital vs. terrestrial solar power fails to add anything to the discussion of the advantages and disadvantages of an asteroid-based orbital fortress. There are other uses for such a fortress besides defending satellites.

A single asteroid-fortress would have to be attacked by dozens of warships to even the odds, for instance.

The OP was about the uses and potential of building a space fortress, not about solar power.

Aye.

Any weapon system can be overcome. A M1 tank can be killed by a 1920s military force. But the cost in lives and equipment would be ludicrous. The point of a space fortress is not be invincible but to make it unfeasible to attack. Asteroids themselves are cheap as platforms go being naturally available.

[PeZook]

Asteroids may be cheap but moving them to a place you want them to be at is not.

[Sarevok]

Uh Formless you are doing it wrong. Ground based solar is all we got so don't dismiss them so casually. Nobody has a realistic proposal for manufacturing solar power satellites yet.

[Imperial528]

I've been lurking this thread for the past few days, and it got me thinking. Obviously, as far as cheapness and resilience goes, mined-out asteroids are the way to make a space fortress.

But, if you can't move an asteroid (either practically or economically) and there aren't any in the orbit you need a fortress at, you're stuck with artificial ones, which are much more frail.

The idea just occurred to me that you could make a hybrid base/satellite system, you can have the center of the fortress, consisting of whatever habitation systems needed, which ideally are few long term and several short term modules, then a sensor and major computing modules, and finally a manufacturing facility.
Then you have a swarm of offensive and defensive satellites in the same orbit controlled by the center station and manufactured by it. It's not as vulnerable as a single station to long-range attack, and it's much more robust in both offensive and defensive capabilities, since its weapons platforms are decentralized and you can't knock them out in one hit. Admittedly this idea is much more suited to solar orbits rather than planetary ones.

[Formless]

Uh Formless you are doing it wrong. Ground based solar is all we got so don't dismiss them so casually. Nobody has a realistic proposal for manufacturing solar power satellites yet.

Earth to Sarovok: I'm not dismissing them, I'm saying that they are not revolutionary like SI thinks they are. Also, you obviously haven't heard about the Japanese project to do just this. So in fact, it is he who is dismissing an idea casually without justification.

[Skgoa]

Pezook pointed it out on the last page, but since no one adressed it yet and I had meant to post this before...

In order to make a space fortress viable, you went to such extremes that its pretty unrealistic the threat model it was meant to defeat would stay the way you imagine it. (Even if we ignore for a second that whatever the space fortress can do can be achieved at a much smaller cost by more conventional means.)
Or to put it differently: my global fleet of laser-armed nuclear submarines numbering in the millions just vaporized your petty asteroid base. Your move.

The idea just occurred to me that you could make a hybrid base/satellite system, you can have the center of the fortress, consisting of whatever habitation systems needed, which ideally are few long term and several short term modules, then a sensor and major computing modules, and finally a manufacturing facility.
Then you have a swarm of offensive and defensive satellites in the same orbit controlled by the center station and manufactured by it. It's not as vulnerable as a single station to long-range attack, and it's much more robust in both offensive and defensive capabilities, since its weapons platforms are decentralized and you can't knock them out in one hit. Admittedly this idea is much more suited to solar orbits rather than planetary ones.

And then a bag of ball bearings rips your whole fortress to shreds...

[Simon_Jester]

Please, elaborate, what breakthroughs and technology do you consider sufficiently convincing?

First of all, only one of those had to do with energy storage, and the article was from 2008. Where is this so called green energy revolution promised three years ago? What you don't understand is that cutting edge technology rarely pans out.

Formless, real technology can't be put into production over the weekend.

The first integrated circuit was invented around 1960. If someone had predicted then that integrated circuits would revolutionize everything from communications to automobile efficiency to how we look things up in the dictionary, what would you say? Would you turn around in 1963 and say:

"Where's my super-efficient car, my pocket radiophone, my automatic dictionary? This technology is lame, it's just a fad."

Thing is, every one of the predictions would come true- eventually. They did come true. But in 1963, the role of integrated circuits was limited to stuff like missile guidance computers. These things take time to permeate the market.

I've heard a lot of things from pop-science rags promising this that and the other with regards to solar, wind, nuclear, and other technologies green and otherwise futuristic, and how many of them pan out? Precious few.

A lot of things pan out; they just take longer than your attention span to pan out.

And you don't notice them when they're in operation, because who goes sniffing around new-build power plants to see whether they make use of technology patented within the last decade?

Pop-science publications tend to repeat the same promises every time they do a piece on a given subject. Every time solar power is mentioned, they talk about how great it would be to have near-perfect solar cells. Every time someone makes an incremental advance in fuel cell technology, they talk about how great fuel cells are. And so on.

That doesn't mean you have a right to expect a massive technological revolution every time Popular Mechanics publishes an article, or to feel cheated when the revolution doesn't come within six months. Or however long it takes you to decide that some bleeding-edge prototype "didn't pan out" because it's not in mass production yet.

Hence, any discussion has to be about technologies we know work or will work, not technologies that are still in beta at best. While there are certainly issues to be resolved with power stations in space, they are not nearly as reliant on stuff that still needs work in the lab. Hence, the only thing really in the way is the logistics, and so far you haven't actually shown why that should sway our hands.

And you are comparing this to ground-based solar, which as zero unsolved problems that still need work in the lab (since it's already in use) and zero unsolved logistics problems (since it's already in use)?

Formless, you're being silly.

You are a fucking broken record. I don't care how much energy hits the earth, what matters is how much of it actually can be converted into usable energy in a consistent manner. If cloud cover can shut off the power grid right during peak hours, people will still rely on good old fashioned coal fired plants and the green revolution is doomed. (At least, assuming nuclear never gets back its old prestige, which I do doubt it ever will)

Ability to store power does a lot for this. So does having backup plants that only run when the solar panels aren't working. This is not an amazing revelation: the idea that you can have a coal-fired plant that only generates electricity when other plants aren't doing the job is not all that difficult.

And this obvious solution greatly reduces the number of kilowatt-hours of energy produced by burning coal, because whenever the sun is shining in Nevada, and whenever the capacitor banks charged by the solar farms in Nevada still hold charge, you can use those to power things with green energy- reserving coal for stopgap purposes.

You don't even need to use coal for this. A really obvious choice to complement solar power is hydroelectric, because it's highly storable. Let the reservoir fill during the day, then run the turbines at night when the solar cells aren't gathering power.

There's no reason for anyone (you or Singular Intellect) to be super-enthusiastic about unproven Grand Engineering Projects when well-proven systems can do the same job well enough.

[Formless]

Okay, back to that ever arrogantly named persona Singular Intellect:

You think carrying payloads, delivering upgrades, simple maintenance and logistics in orbit has any kind of cost effectiveness or practicality compared to doing so on dry land and the ocean? What the fuck are you smoking?

And? Space doesn't have a whole lot of things that wear out machinary like the ground does. Are appeals to incredulity all you have to go by?

See above. Ballpark figures are our planet receives ten thousand times more energy than our entire civilization consumes, we need to only tap a tiny fraction of it to meet all our energy needs.

See my previous link on energy input from the sun hitting the surface of our planet. We have more than what we know what to do with.

Someone should name a logic fallacy after what you are doing. Simply having an abundant resource does not equate to having practical, reliable access to that resource.

They're not fantasy. They're being built as we speak, you ignorant simpleton.

Great, now address the problems with wide scale deployment of such schemes. Jeez, even the paper you quote names a few:

However, building such a facility involves a few restrictions. There has to be around 350 days a year of sunshine, and it needs to sit somewhere between the tropics, near the equator for optimal performance. In many respects, the coastal region of the UAE fits the bill, and this is why RAK is footing a large part of the development costs, contributing $5 million to the project. He added that "we began working on renewable energies with the emirate three years ago, indicating that the market with the biggest potential for solar energy and water technology".

Bolding is again mine. Most of the earth's population does not live where this scheme would be optimal, meaning that most of us will be restricted to using other power options like coal, nuclear, wind, and yes space based solar power.

Futhermore, it would be vastly easier to repair and maintain systems on dry land and the nearby ocean than in fucking orbit. Or do you think space based solar plants with necessarily large surface areas would be immune to significant problems like space debris?

And how much of a danger is space debris in comparison to the constant threat of bad weather? Again: simply throwing out talking points does not sway an argument ot your favor, Bubble Boy.

Yeah, too bad we haven't figured out how to make shit float yet.

There is a difference between floating a boat around that needs constant maintenance and has a crew always at hand to do said maintenance and floating a small island that needs to be constantly anchored in one spot 365 days a year to supply a poplation center. One is easy, the other is hard (and expensive). For one thing, the larger the object you want to float, the more of a problem ordinary waves become due to the fact that the island has to be able to bend with them. Size matters in the real world.

Yeah, beause our capability to implement infrastructure in space even remotely compares to doing so on land or the ocean, right?

Oh, yeah, that really answers the question doesn't it.

Once again: how do you propose mass deployment of these islands when it costs millions to billions of dollars to float just one oil rig in comparitively shallow seas? You can complain about the logistic of space based solar power all you want, but that does not excuse you from making proposals that are just as rediculous in their own ways.

Solar power is a decentralized energy source. You don't need to live near the ocean. Anywhere you see the sun will do just fine.

You guys don't get sunshine? That's news to me.

Seriously though, this is one of the stupidest fucking questions I've ever seen regarding solar power.

Except that in the winter the day gets as short as ~8 hours at this lattitude. Do you even think before throwing out your talking points? Because the evidence so far suggests that you don't.

Yeah, utterly insignificant portions of the ocean having artificial islands floating on it would be so disruptive! Especially since all they are doing is collecting that damn polluting sunlight!

I'm the dumbass, eh?

I was thinking of the pollution created by installing those rediculous things, Bubbles. What, oceangoing ships don't create pollution now?

[Formless]

Formless, real technology can't be put into production over the weekend.

You miss the point. The technology he is proposing isn't just a matter of improving engineering, its a matter of discovering completely new processes that we don't have yet. Also, it takes a long time to make improvements, but with regards to energy technology we do not have the time to wait for these inventions to be slowly improved. Integrated circuits were not a matter of civilizations rising or falling, whereas solar very well might. So as far as I am concerned, if we want to talk about the pros and cons of technology x vs y we have to talk about the technologies that are known, not unknown.

A lot of things pan out; they just take longer than your attention span to pan out.

This would be a lot more profound if the promises made weren't made in the short term. They want to capture people's attention, even when the future of that technology is in question. You read that article about the "decline effect" in science? Well, its effects are quite a bit more obvious when you look at engineering and futurism. Hence my skepticism with SI's wild claims that ground based solar power will revolutionize the world while space based schemes are apparantly devoid of all worth.

Its not that I dismiss anything that ends up in Popular Mechanics: indeed, space based solar power schemes are themselves the kind of futuristic thing those magazines are drawn to. Its just that I don't get my hopes up, nor dismiss proposals I don't like or find intuitive.

And you are comparing this to ground-based solar, which as zero unsolved problems that still need work in the lab (since it's already in use) and zero unsolved logistics problems (since it's already in use)?

Formless, you're being silly.

Simon, I'm talking about hydrogen fuel cells. Its related to the ground based solar power bit by the fact that the article SI linked to proposed storing energy in hydrogen fuel cells, an idea I've seen toted around for over a decade without panning out.

Ability to store power does a lot for this. So does having backup plants that only run when the solar panels aren't working. This is not an amazing revelation: the idea that you can have a coal-fired plant that only generates electricity when other plants aren't doing the job is not all that difficult.

And this obvious solution greatly reduces the number of kilowatt-hours of energy produced by burning coal, because whenever the sun is shining in Nevada, and whenever the capacitor banks charged by the solar farms in Nevada still hold charge, you can use those to power things with green energy- reserving coal for stopgap purposes.

You don't even need to use coal for this. A really obvious choice to complement solar power is hydroelectric, because it's highly storable. Let the reservoir fill during the day, then run the turbines at night when the solar cells aren't gathering power.

There's no reason for anyone (you or Singular Intellect) to be super-enthusiastic about unproven Grand Engineering Projects when well-proven systems can do the same job well enough.

This I do not disagree with. But then, see my reply to Sarevok: what irritates me is that the space based idea was rejected out of hand. I never said I thought it would be a magic pill, just that its not as bad an idea as he makes it out to be.

[eion]

A single asteroid-fortress would have to be attacked by dozens of warships to even the odds, for instance.

I'm curious. What's a "warship"?

That would depend entirely on how advanced the society is. It could be anything from a converted explorer with a couple missiles strapped to it to an armored laser-packed bruiser. The point is that the cooling capacity of a warship will always be lower than an asteroid fortress that can spend every non-combat moment cooling its massive heat-sink, also known as all the cubic kilometers of rock it's built into.

[Imperial528]

And then a bag of ball bearings rips your whole fortress to shreds...

I think that's simplifying things a bit... much, to understate. At the range which you could fire a few shots without having the swarm respond immediately, you'd have to use a missile to deliver the "ball bearings", which of course can simply be intercepted by the defensive satellites, even if they have to simply shift orbit to be in the way of it.

Closing in to get off a shot that can't be intercepted by anti-missile systems would surely bring you within the swarm's firing range.
Not to mention that the sheer amount of metal required to actually shred it would be so huge and so much would go to waste that it wouldn't be worth it. From what I can tell, you're thinking of shooting a large amount of micro-meteorite sized shrapnel at it. It'd definitely be a hindrance, and it'd be a pain to fix, but even a few hundred hits wouldn't be enough to kill it outright, and I doubt that you'd be accurate enough to even hit it with that many.

[Simon_Jester]

And? Space doesn't have a whole lot of things that wear out machinary like the ground does. Are appeals to incredulity all you have to go by?

In exchange, it picks up others: radiation damage, micrometeoroids... plus, anything that does fail is going to be enormously harder to replace, orders of magnitude harder. When something breaks on the ground, you send a guy out with a wrench. When something breaks in orbit, even if you have astronauts on hand to fix it, you need an extensively planned EVA operation where everything needs to be moved and stowed very carefully.

So I don't think this issue can be handwaved.

There is a difference between floating a boat around that needs constant maintenance and has a crew always at hand to do said maintenance and floating a small island that needs to be constantly anchored in one spot 365 days a year to supply a poplation center. One is easy, the other is hard (and expensive). For one thing, the larger the object you want to float, the more of a problem ordinary waves become due to the fact that the island has to be able to bend with them. Size matters in the real world.

This is true. On the other hand, it's also more of a solved problem than you would believe. Artificial islands aren't uncommon or new; nor are stationary platforms out in the deep ocean (like oil rigs).

Yeah, beause our capability to implement infrastructure in space even remotely compares to doing so on land or the ocean, right?

Oh, yeah, that really answers the question doesn't it.

Once again: how do you propose mass deployment of these islands when it costs millions to billions of dollars to float just one oil rig in comparitively shallow seas? You can complain about the logistic of space based solar power all you want, but that does not excuse you from making proposals that are just as rediculous in their own ways.

Formless, could you write out a comparison of costs per kilogram to orbit versus costs per kilogram to artificial island? Oil rigs weigh in the tens of thousands of tons; even positing dirt cheap space launch (say, 10$/kg), you get very large budgets to put something of comparable mass into orbit.

And you are comparing this to ground-based solar, which as zero unsolved problems that still need work in the lab (since it's already in use) and zero unsolved logistics problems (since it's already in use)?

In use for (much) less than 1% of energy generation in the United States.

Yes. However, it's scalable.

Once you have built one of something, building the second, the fifth, the tenth, and the twentieth becomes a lot easier. You can make rational estimates of how much it will cost. The size of the "unknown unknown" problems likely to crop up in construction shrink a lot. You can start turning the tricky finicky hardware that needs specialists to monitor into more user-friendly hardware that ordinary technicians can handle. And so on.

Solar power in the US on the ground is scalable; we could build more of it if we wanted to spend the money doing so. It would not be in any way impractical, and we can work out the costs in advance by taking the numbers from existing projects, adding minor corrections, and multiplying.

Solar power in orbit is not scalable, because there is nothing to scale it to. We have no prototypes to base our construction on. Nothing like it has ever been done, or even seriously considered.* All we have are projections of how much it is going to cost, projections which usually depend on assumptions that cannot be tested until we actually start cutting metal. This makes a huge difference if we're seriously interested in solving a problem any time in the next few decades, rather than just wanting to wave our hands and blather about how in the future we will have X and it will solve all our problems.

*If you aren't planning to pony up the money to do it in the near future, you aren't seriously planning something in engineering.

You miss the point. The technology he is proposing isn't just a matter of improving engineering, its a matter of discovering completely new processes that we don't have yet. Also, it takes a long time to make improvements, but with regards to energy technology we do not have the time to wait for these inventions to be slowly improved. Integrated circuits were not a matter of civilizations rising or falling, whereas solar very well might. So as far as I am concerned, if we want to talk about the pros and cons of technology x vs y we have to talk about the technologies that are known, not unknown.

Since space-based solar will make use of all the same technologies as ground-based solar and then some, I don't think it comes out very well in debates under those rules.

Remember, coming up with more efficient solar cells makes a huge difference to the feasibility of solar power satellites... as does reducing space launch costs. Any realistic estimate on the viability of SPS will depend very heavily on advances in solar power technology and the aerospace industry. You don't simplify your problem by putting the problem into orbit.

I'm not going to stick up for any "this will transform the world!" claims made by SI, since I have little reason to assume he knows what he's talking about. But I do think it's disingenuous to present untried solar power satellites as a "more realistic" alternative to equally untried ground-based solar power plants.

A lot of things pan out; they just take longer than your attention span to pan out.

This would be a lot more profound if the promises made weren't made in the short term. They want to capture people's attention, even when the future of that technology is in question. You read that article about the "decline effect" in science? Well, its effects are quite a bit more obvious when you look at engineering and futurism. Hence my skepticism with SI's wild claims that ground based solar power will revolutionize the world while space based schemes are apparantly devoid of all worth.

Look, Formless, what I want to get at is that the advantage of putting X tons of cells into space doesn't necessarily beat the advantage of putting 10X tons of cells on the ground at the same cost. Anything that improves solar power efficiency (or power storage) affects both systems more or less equivalently... and ground will still tend to win out over space on launch costs. If it's a choice between picking up eight times as much power per square kilometer of cells in space, while losing half of it in transmission, or building four times as many cheap cells for the same net price on the ground, space doesn't beat ground.

This I do not disagree with. But then, see my reply to Sarevok: what irritates me is that the space based idea was rejected out of hand. I never said I thought it would be a magic pill, just that its not as bad an idea as he makes it out to be.

I think it gets rejected out of hand because it relies on too many technical advances: cheap space launch, solar cells that are lightweight and high efficiency, a mechanism for transmitting beamed power to the ground...

There are a lot of things there where someone's done a design study, but no one's ever actually cut metal on a working system to test cost-effectiveness. In that respect it's like fusion power: sure it might be the killer app of the 23rd century, but for now we don't know enough to know whether it'll work.

Hence the tendency to dismiss it in favor of just building ten times more copies of something we already have and know we can build.

[Purple]

I have a question. Does not anyone who can drag an asteroid into orbit also have the capacity to drag and drop a much smaller one from orbit? Does that not produce sufficient deterrence on it's own?

[Simon_Jester]

I have a question. Does not anyone who can drag an asteroid into orbit also have the capacity to drag and drop a much smaller one from orbit? Does that not produce sufficient deterrence on it's own?

It may not be practical to do this quickly, in which case its deterrent effect is limited.

EDIT: There are ways to neutralize a slow-acting deterrent. For example, suppose the nations of Simonia and Purplistan fight a nuclear war. During the war, you leave my population centers more or less alone. however, Purplistani forces destroy the ground-based nuclear arsenal of the Simonian military, or neutralize them by sabotage or by pulling a new superweapon out of a hat. All that remains is the Simonian space-based deterrent force.

Now, what happens if you, Purple, say the following to me (or my successor if I got nuked):

"Disarm your space-based deterrent force, or I will use my remaining nuclear arsenal to lay waste to your (still largely intact) population centers."

At that point, I'd be a damn fool not to disarm my space-based deterrent.

The only insurance I can have against this kind of trick is to be sure that my deterrent can strike you before you have the leisure time to work out a plan like this. I must be able to hit you before you reduce me to a state where I'm helpless enough to be vulnerable to such blackmail. Redirected asteroids that take weeks or months to move into position don't qualify.

Where is your transmission efficiency number coming from? The worst I've seen is 85% - no where near losing half.

Pulled out of a hat. Chosen not as a representative sample, but only because it's easier to say:

"Build one panel that generates 8X power at 50% transmission efficiency, or four panels that generate X power at 100%, and get 4X power either way"

Than it is to say:

"Build ten panels that generate 6X power at 85% transmission efficiency versus fifty panels that generate X power each at 100% efficiency, and get 50X power either way."

The arithmetic is the same; it's just easier to do in your head, and I'm trying to generate an illustrative example people can assimilate quickly here.