...100 MW of Space Solar Power ...per single launch!
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From: jimp on 17 Dec 2009 16:03 In sci.physics "Greg D. Moore \(Strider\)" <mooregr_delet3th1s(a)greenms.com> wrote: > <jimp(a)specsol.spam.sux.com> wrote in message > news:cmaqv6-t24.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: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". > > Yes, in a physics sense. Since you're the one claiming the power density is > too low to work. I never claimed that. What I said was it wouldn't be particularly usefull at very low levels. > If you want to make a DIFFERENT argument, based on economy, not physics, > fine by me, but be clear that you're changing your argument. You are the one that brought up terresterial solar power, not me. > Of course on the economic front, you won't get much of an argument from me. > I've seen nothing to convince me the economics of SPS works in any near-term > future. But the physics, they certainly work. Sure, the physics works for all kinds of things that have no practical use and/or are too expensive to use. -- Jim Pennino Remove .spam.sux to reply.
From: jimp on 17 Dec 2009 16:10 In sci.physics Alain Fournier <alain245(a)sympatico.ca> wrote: > jimp(a)specsol.spam.sux.com wrote: > >> In sci.physics Alain Fournier <alain245(a)sympatico.ca> wrote: >> >>>jimp(a)specsol.spam.sux.com wrote: >>> >>> >>>>In sci.physics Alain Fournier <alain245(a)sympatico.ca> wrote: >>>> >>>> >>>>>jimp(a)specsol.spam.sux.com wrote: >>>>> >>>>> >>>>> >>>>>>In sci.physics Peter Fairbrother <zenadsl6186(a)zen.co.uk> wrote: >>>>>> >>>>>> >>>>>> >>>>>>>Alain Fournier wrote: >>>>>> >>>>>>>However there would be other benefits to starting a space-based economy, >>>>>>>for instance things can be made in space which are impossible or >>>>>>>expensive to make on Earth >>>>>> >>>>>>Name something that is impossible to make on Earth or would be cheaper >>>>>>to make in space for which there is an actual market. >>>>> >>>>>Well there is no market for something that doesn't exist, so there >>>>>is currently no market for things that are impossible to make on Earth. >>>>>But here are a few things that a space based industry could possibly do. >>>>> >>>>>- Alloys made of metals of very different densities. >>>>>- Metal mousse (kind of a metal air alloy, or a metal vacuum alloy(??) ). >>>>>- It is suspected that some crystals next to impossible to grow on >>>>>Earth could be made in zero g. >>>>> >>>>>But I think that a space based industry would probably not be exporting >>>>>hardware to Earth, at least not at first. Exports to Earth would probably >>>>>at first be data and/or energy. So a space based industry could build >>>>> >>>>>- SPS >>>>>- Giant space telescopes. >>>>>- Fuel for interplanetary probes and interplanetary manned missions. >>>>>- Interplanetary probes or parts of them. >>>>> >>>>>Would you like more? >>>> >>>> >>>>What I would like is to hear of is an industrial product that would be >>>>purchased in the commercial marketplace. >>> >>>As I said "there is there is no market for something that doesn't exist, so >>>there is currently no market for things that are impossible to make on Earth. >>> >>>But I see no reason why >>> >>>>>- Alloys made of metals of very different densities. >>>>>- Metal mousse (kind of a metal air alloy, or a metal vacuum alloy(??) ). >>>>>- It is suspected that some crystals next to impossible to grow on >>>>>Earth could be made in zero g. >>> >>>could not be traded in a commercial marketplace. >>> >>> >>>Alain Fournier >> >> >> It depends on whether or not there is some actual use for those items and >> if they could be made at a marketable price. > > Yes. Well there are clearly some uses for the metal alloys and mousse. > Whether they could be made at a marketable price is an open question. > For small quantities, the answer is clearly no. But for larger quantities > who knows. > >> All of which at this point is arm-waving conjecture. > > I'm not saying that one can clearly become rich by starting a space based > industry right now. What I said is that if you want to build SPSs, there > is an option you should consider. That is to build it in space from space > based material (asteroids) instead of doing it all from Earth. If you do > it from space based materials, there *might* be additional things you > can do with the stuff you mine. As is the case most of the time with > a new product, a new process or a new material, there is some uncertainty. > But you can't write it all off as impossible without doing a serious effort > to see if is feasible, sensible and profitable. > > > Alain Fournier I never said anything was "impossible", just not economically feasible. Mining and refining raw material on Earth, making the materials into subassemblies, shipping the subassemblies into space, and then putting the system (whatever it is) together is going to be a lot cheaper than any other alternative for the foreseeable future absent some shattering new discovery along the lines of Star Trek technology. -- Jim Pennino Remove .spam.sux to reply.
From: Peter Fairbrother on 17 Dec 2009 17:02 jimp(a)specsol.spam.sux.com wrote: > In sci.physics Peter Fairbrother <zenadsl6186(a)zen.co.uk> wrote: >> 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. > > Both of which are heavily used so there would be no Wi-fi or cordless > phones (among other things) anywhere near this facility. > > Sorry, it should be 5.8 GHz, not 5.2 GHz. Both 2.45 GHz and 5.8 GHZ are ISM (industry, scientific, medical) bands, and aiui are not allowed to be used for communications (part 18, FCC rules, as well as international agreements, prohibit this). Otherwise microwave ovens would interfere with wifi or cordless phones. There should be no interference with wifi or cordless phones. Aiui, in the US you'd need to get an okay from the FCC, but I can't see why they might object, it wouldn't interfere with anything outside the zone. The needed bandwidth is - very small indeed, it's power not communications, and could be used by all the satellites worldwide. The beam would need to be very monochromatic (within < 0.5 ppm) for beamspread reasons anyway. -- Peter Fairbrother
From: jimp on 17 Dec 2009 17:45 In sci.physics Peter Fairbrother <zenadsl6186(a)zen.co.uk> wrote: > jimp(a)specsol.spam.sux.com wrote: >> In sci.physics Peter Fairbrother <zenadsl6186(a)zen.co.uk> wrote: >>> 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. >> >> Both of which are heavily used so there would be no Wi-fi or cordless >> phones (among other things) anywhere near this facility. >> >> > > Sorry, it should be 5.8 GHz, not 5.2 GHz. > > Both 2.45 GHz and 5.8 GHZ are ISM (industry, scientific, medical) bands, > and aiui are not allowed to be used for communications (part 18, FCC > rules, as well as international agreements, prohibit this). Otherwise > microwave ovens would interfere with wifi or cordless phones. > > There should be no interference with wifi or cordless phones. 802.11 devices run in the 2.4 GHz and 5.8 GHz bands in the US (and most of the world) under FCC Part 15 as do cordless phones. Bluetooth is 2450 MHz. HIPERLAN runs at 5.8 GHz. Users of Part 15 devices have no legal recourse if a Part 18 emitter cause interference. And microwave ovens have been known to interfere with wifi and cordless phones. > Aiui, in the US you need to get an okay from the FCC, but I can't see > why they might object, it wouldn't interfere with anything outside the zone. In the US, you need an OK in some form from the FCC for ANY intentional radiator and have you ever heard of side lobes? > The needed bandwidth is - very small indeed, it's power not > communications, and could be used by all the satellites worldwide. The > beam would need to be very monochromatic (within < 0.5 ppm) for > beamspread reasons anyway. For regulatory and practical interference reasons, the frequency would need to be tightly controlled and would likely require coordination with the ITU for a globally acceptable frequency to use. Just one more practical hurdle that no one seems to want to talk about. -- Jim Pennino Remove .spam.sux to reply.
From: Pat Flannery on 17 Dec 2009 20:42
Alain Fournier wrote: > > As I said "there is there is no market for something that doesn't exist, so > there is currently no market for things that are impossible to make on > Earth. > > But I see no reason why > >>- Alloys made of metals of very different densities. > >>- Metal mousse (kind of a metal air alloy, or a metal vacuum > alloy(??) ). > >>- It is suspected that some crystals next to impossible to grow on > >>Earth could be made in zero g. > > could not be traded in a commercial marketplace. Considering the production cost per pound to get the raw materials up to the space manufacturing facility and the finished product back down to Earth, you might well trade them like gold or platinum. These materials would have to do some pretty amazing things to make their production and use economically feasible. You could make cars out of titanium and save some pounds as well as reducing fuel use, but is it worth the added cost and production difficulty? Pat |