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{ "url": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/2W5FASVWIRKHGSCMVP42TSKUCMWTVBH6/", "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/", "message_id": "[email protected]", "message_id_hash": "2W5FASVWIRKHGSCMVP42TSKUCMWTVBH6", "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/2W5FASVWIRKHGSCMVP42TSKUCMWTVBH6/", "sender": { "address": "prinaldo (a) mindspring.com", "mailman_id": null, "emails": null }, "sender_name": "Paul L Rinaldo", "subject": "[eagle] Re: Solar Power Systems -- White Paper FYI", "date": "2006-11-13T19:37:27Z", "parent": null, "children": [], "votes": { "likes": 0, "dislikes": 0, "status": "neutral" }, "content": "Tom,\n\n\nWe've been watching this subject for some time in ITU-R Study Group 1\n(spectrum management). As I'll be traveling this week, I've asked Jon\nSiverling to review the relevant ITU documents and advise.\n\n\nPaul\n\n\nAt 01:59 AM 11/11/2006 -0500, Tom Clark, K3IO wrote: \n\n>>>>\n\n I am a member of URSI (International Scientific Radio Union)\nCommission J (Radio Astronomy). The US National Committee of URSI has\nasked its members to review the attached document on Orbiting Solar Power\nStations. I send it along to you for information. You will see that the\nconcepts might involve Microwave Power transmission at S-Band (2.45 GHz)\nand/or C-band (5.8 GHz). In the main footprint of the beam, the power\nflux density might reach (near fatal!) levels of ~300W/m. \n\n\nThe orbiting antenna will certainly have sidelobes likely would wipe out\nmany services. You will note comments indicating that that this worries\nmany radio astronomers who routinely make measurements as sources with\nflux densities of 1 mJy (1 Jansky =s a power flux density of 1x10e-26\nw/(mHz) . In the event of a failure of just one active element, the\nbeam-forming properties of the orbiting antenna would certainly degrade.\nInside the report you will note a statement that even with a MTBF of ~30\nyears for magnetrons, this implies a failure of one element/day for the\narray!\n\n\nIt is interesting to note that the report indicates current launch costs\nof ~$10,000/kg (this is about the going rate for a Dnepr launch to LEO),\ndecreasing significantly by 2025 (good news for us, if true). It is also\ninteresting to note that the report still indicates the use of\n(relatively) low efficiency solar cells and doesn't even note the ~28%\ncells that we have been using.\n\n\nI have no idea of the reality of these systems. I presume that\nAMSAT/ARRL/IARU could make comments to URSI. The following is the\n\"charge\" given to URSI members which calls for responses a scan 1 weeks\nhence:\n\n\n <fontfamily><param>Helvetica,</param>Dear USNC-URSI Colleagues: \n\n \n\nThe past president of URSI, Professor Kristian Schlegel, has asked me for\n \n\nthe USNC opinion on the proposed URSI white paper on solar power, copy of\n \n\nwhich is attached. Even though it appears that the conclusion is foregone\n \n\nbecause a majority of URSI member countries are in favor of the proposal,\n \n\nit is important that the US opinion be registered and our objections, if \n \n\nany, be forwarded to URSI and remain a matter of record. I am therefore \n \n\nasking that you let me have your reactions by e-mail on or before Monday,\n \n\nNovember 20. I will collate them into a memorandum that I will send to \n \n\nProf. Schlegel by his deadline of November 22. It is especially important\n \n\nthat I hear from the Commission Chairs, and crucial that I receive the \n \n\nopinion of Commission J. \n\n \n\nI apologize for the short notice. I was hoping that we could discuss this\n \n\nmatter at the USNC business meeting in Ottawa next summer, but it now \n\nappears that URSI is in a hurry to decide the issue soon, and is not \n\nwilling to wait. \n\n \n\nBest regards, \n\n \n\nGeorge Uslenghi \n\nChair of USNC-URSI. \n\n_________________________________________ \n\nPiergiorgio L. E. Uslenghi, Ph.D. \n\nProfessor and Associate Dean \n\nDepartment of ECE, College of Engineering \n\nUniversity of Illinois at Chicago \n\n851 South Morgan Street, Chicago, IL 60607, USA</fontfamily> \n\nDave Woodie (CalTech), the current USNC Commission J chairman, appended\nthese notes from last January's submission by the Radio Astronomers:\n\n\n <fontfamily><param>Helvetica,</param>Discussion of the solar satellite\nwhite paper: Commission J members are concerned about the process for\nproducing such a white paper and whether there is an implied approval by\neach commission. Many of the issues with this project are beyond the\ntechnical scope of the URSI commissions and hence it is inappropriate for\nURSI to take a strong position on this project. Individual commission J\nmembers expressed strong reservations about this project and do not want\nto be associated with a white paper supporting solar satellites for beam\npower to earth. (The commission J chair, David Woody, expressed these\nconcerns to the URSI executives during the Saturday morning executive\nsession.)</fontfamily> Comments?\n\n\n73, Tom\n\n\n\n\nAttachment Converted: \"c:\\eudora\\attach\\URSI white paper on solar\npower.doc\" \n\n\n\n\n\n", "attachments": [ { "email": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/2W5FASVWIRKHGSCMVP42TSKUCMWTVBH6/", "counter": 0, "name": "attachment.bin", "content_type": "text/enriched", "encoding": "us-ascii", "size": 4451, "download": "https://mailman.amsat.org/hyperkitty/list/[email protected]/message/2W5FASVWIRKHGSCMVP42TSKUCMWTVBH6/attachment/0/attachment.bin" } ] }