...100 MW of Space Solar Power ...per single launch!
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From: Peter Fairbrother on 17 Dec 2009 13:32 jimp(a)specsol.spam.sux.com wrote: > The amount of recoverable energy is directly proportional to the energy > density for a given area. Yes. > > The amount of lawsuits generated and the costs for a ground station are > directly proportional to the ground area. Yes, roughly. But .. > > The wave length can not be chosen as a "convenient" one but must be in > an ISM band as governed in the US by Part 18 of the FCC rules. ... which brings some physics into play. It will also have to be convenient in the sense that it is in the atmospheric window (the range of frequencies where the atmosphere is transparent). The main contenders are 2.45 GHz as used for microwave ovens, and 5.2 GHz. The physics involved means that ground antenna sizes will be in the 3-7 mile diameter range, regardless of total power or power density. There will also need to be an exclusion zone around the actual antenna, where the power density is too small to make an antenna worthwhile, but too powerful for people to stay long-term. For all practical purposes, a ground station is pretty much the same size, and the same cost, no matter how powerful it is. Yes more powerful ones are bigger, but including exclusion zones it's something like 15 miles for 100 GW and 10 miles for 100 MW - twice the area, but 1,000 times the power. You might as well go for a very high power one then, and the power density could well be in the very dangerous range, about the same as noonday sun in the antenna area, far above any reasonable long-term, or even medium-term, exposure limits (though not immediately fatal even then, though tinfoil hats would be required for survival over a day) - and it would still above practical limits for long-term exposure in the exclusion zone. Using 5.2 GHz means the antennas can be smaller. 5.2 GHz antenna hardware will probably be more expensive than 2.45 GHz overall, even though smaller, but this extra cost will most likely be swamped by the much cheaper cost of the ground antenna (including lawsuits etc) at 5.2 GHz (and cheaper launch costs). 5.2 GHz is also thought to be safer than 2,45 GHz, with higher exposure limits. I *think* it is however used a bit, unlike 2,45 GHz, and the FCC would need to rearrange the allocations a little - not very expensive in compensation costs, but a hassle. > > RF exposure level standards for continuous exposure will have to be met. Yes. > > The NIMBY's get their panties in a wad over "radiation" from cell phone > towers. Indeed - but you'd have to move the nimby's out anyway. That's where the real cost comes in! -- Peter Fairbrother
From: Peter Fairbrother on 17 Dec 2009 13:39 jimp(a)specsol.spam.sux.com wrote: > > What I would like is to hear of is an industrial product that would be > purchased in the commercial marketplace. > > Foamed metal bicycle frames? Maybe semiconductor crystals? It depends on the cost of manufacturing in space, which depends on the existing launch market, and the existing space industrial capacity. It's a bit of a chicken-and-egg situation, once a space industry is started making things gets cheaper, and more products will become economic. -- Peter Fairbrother
From: jimp on 17 Dec 2009 13:39 In sci.physics "Greg D. Moore \(Strider\)" <mooregr_delet3th1s(a)greenms.com> wrote: > <jimp(a)specsol.spam.sux.com> wrote in message > news:683qv6-963.ln1(a)mail.specsol.com... >> In sci.physics Fred J. McCall <fjmccall(a)gmail.com> wrote: >>> jimp(a)specsol.spam.sux.com wrote: >>> >>> :In sci.physics "Greg D. Moore \(Strider\)" >>> <mooregr_delet3th1s(a)greenms.com> wrote: >>> :> <jimp(a)specsol.spam.sux.com> wrote in message >>> :> news:lc3ov6-5mp.ln1(a)mail.specsol.com... >>> :>> In sci.physics "Greg D. Moore \(Strider\)" >>> :>> <mooregr_delet3th1s(a)greenms.com> wrote: >>> :>>> <jimp(a)specsol.spam.sux.com> wrote in message >>> :>>> news:fqrnv6-6so.ln1(a)mail.specsol.com... >>> :>>>> >>> :>>>> For existing things there is the concept of minimum enroute >>> altitude >>> :>>>> which ensures you are above all the obstacles for a significant >>> :>>>> distance. >>> :>>>> >>> :>>>> There is no getting above an energy beam from space. >>> :>>>> >>> :>>> >>> :>>> And yet people still fly into the ground or buildings. Again, it's >>> the >>> :>>> pilot's fault. Not the build, ground or beam. >>> :>> >>> :>> Apples and oranges. >>> :>> >>> :>> How do you avoid something that is invisible to all existing aviation >>> :>> sensors? >>> :> >>> :> Same way pilots avoid no-fly zones now. They consult their maps and >>> NOTAMs >>> :> and fly around them. >>> :> >>> :>> >>> :>> While flying VFR, obstacles are avoided by eyesight and altitude, >>> neither >>> :>> of which will work with an energy beam from space. >>> :>> >>> :> >>> :> Pilots flying VFR avoid no-fly zones now. I'm not sure why in the >>> future >>> :> you think they're suddenly going to become stupid. >>> :> >>> :> In any case, at the energies discussed, the power levels just aren't >>> that >>> :> dangerous. >>> : >>> :If the energy density is low enough to be safe, it isn't high enough to >>> :be particularly usefull. >>> : >>> >>> Wrong. >> >> Right. >> >> Lookup the the microwave energy density levels concidered safe for >> continuous exposure. >> > > I did. Have you? Do you know what the expected density is or are you just > blowing smoke? So what is it exactly? > And who said anything about continuous exposure. If you're in a plane, > you're in the beam for a few minutes at most. What about the people and wildlife at the ground station or will this be enclosed by triple barbed wire, electified fences, and never require anyone on site for anything? -- Jim Pennino Remove .spam.sux to reply.
From: jimp on 17 Dec 2009 13:42 In sci.physics "Greg D. Moore \(Strider\)" <mooregr_delet3th1s(a)greenms.com> wrote: > <jimp(a)specsol.spam.sux.com> wrote in message > news:623qv6-963.ln1(a)mail.specsol.com... >> In sci.physics "Greg D. Moore \(Strider\)" >> <mooregr_delet3th1s(a)greenms.com> wrote: >>> <jimp(a)specsol.spam.sux.com> wrote in message >>> news:6isov6-47s.ln1(a)mail.specsol.com... >>>> In sci.physics "Greg D. Moore \(Strider\)" >>>> <mooregr_delet3th1s(a)greenms.com> wrote: >>>> >>>> If the energy density is low enough to be safe, it isn't high enough to >>>> be particularly usefull. >>>> >>>> >>> >>> In other words you've just proven terresterial solar power doesn't work >>> either. I'll go tell the folks I know using it that you've proven their >>> systems don't work. >> >> Terresterial solar power as a general source of electrical power (as >> opposed >> to niche situations) only works today on an economic level because of >> government subsidies in many forms. >> > > Please explain how economics has anything to do with the physics of the > safety of the power density. > > Right, it doesn't. In other words you're creating a strawman here. I never > argued economics. Nothing ever gets built without money. Economics is about money. You "argued" "proven terresterial solar power". -- Jim Pennino Remove .spam.sux to reply.
From: jimp on 17 Dec 2009 13:44
In sci.physics "Greg D. Moore \(Strider\)" <mooregr_delet3th1s(a)greenms.com> wrote: > <jimp(a)specsol.spam.sux.com> wrote in message > news:it3qv6-963.ln1(a)mail.specsol.com... > Umm, yeah, your point? See below. >> If all it took were regulations to keep bad things from happening, there >> would be no robbery, murder, traffic accidents, medical malpractice or >> any other of the inconvienient realities of life. -- Jim Pennino Remove .spam.sux to reply. |