Email Detail
Show an email
GET /hyperkitty/api/list/[email protected]/email/M4EB6Z7IB64ODRR2IPWPCXFZEZXWIFMQ/?format=api
{ "url": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/M4EB6Z7IB64ODRR2IPWPCXFZEZXWIFMQ/?format=api", "mailinglist": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/?format=api", "message_id": "001f01c7c1b6$723038c0$0300a8c0@kc6uqh", "message_id_hash": "M4EB6Z7IB64ODRR2IPWPCXFZEZXWIFMQ", "thread": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/thread/3V3MOF4RB25KWM6OA4CYBPWYFCWKGNQO/?format=api", "sender": { "address": "kc6uqh (a) cox.net", "mailman_id": "d9201820d18047e4a2772c86bda5e111", "emails": "https://mailman.amsat.org/hyperkitty/api/sender/d9201820d18047e4a2772c86bda5e111/emails/?format=api" }, "sender_name": "kc6uqh", "subject": "[amsat-bb] Re: Future radical satellite designs", "date": "2007-07-08T23:19:34Z", "parent": "https://mailman.amsat.org/hyperkitty/api/list/[email protected]/email/EZSXBSTT66AWCJKCM7XQMWCQP3RVEN4J/?format=api", "children": [], "votes": { "likes": 0, "dislikes": 0, "status": "neutral" }, "content": "How about a 50 KW ERP EME station for power? All you need is some power \nrectifiers that work @ 2M and a long boom yagi on the satellite side and we \nhave many EME stations in the US! First atempts of this I belive occured at \nField Day, but the receiver front end protection diodes had too high an \ninternal resistance prevnting full charging of the batteries on AO-51!\nMy .02\nBattery technoloigy is changing, and mutiple batteries with full management \nto drop unmatched cells an still have output should offer the best solution. \nAO-40 demise was related more to hangar age than anything else. Systems \ndegrade with time, and we did not have a firm launch date when construction \nwas started. In the future we need to make the batteries the last part to be \npurchased only after a launch commitment has been made. Several other \nlessons were learned from AO-40 and they too were related to the long time \nbetween the construction and launch of AO-40\n\nArt,\nKC6UQH\n----- Original Message ----- \nFrom: \"Greg D.\" <[email protected]>\nTo: <[email protected]>; <[email protected]>\nSent: Sunday, July 08, 2007 11:46 AM\nSubject: [amsat-bb] Re: Future radical satellite designs\n\n\nInteresting discussion. For my $.02:\n\n1. Consider a sun synchronous orbit to go along with the solar-only\napproach. No eclipse to worry about, though I'm not sure how many years\nsuch an orbit could be maintained before it slides one way or the other,\ne.g. what happened to AO-27 in reverse. So, you would still need to design\nfor eclipse, just not operate there.\n\n2. You don't get max power out of the cells all the time - it depends on\nsun angle. And solar cells degrade over time, and they fail too. Having a\nbattery in the loop can be a very good thing, e.g. what happened to PCSAT.\nPerhaps a compromise, use some of those new mega capacitors? I understand\nthat they are not space-rated yet, but perhaps \"we\" could help in that\nregard...\n\n3. Not to burst your bubble, but I believe one of the cubesats recently\nlaunched uses a no-battery design.\n\n4. We know AO-40's power system has failed, or at least is not capable of\npowering the bird. I haven't heard that we know cause vs effect; another\n\"urp\" of from the rocket system, or leaking nasty stuff all over the wires\ncould be the cause. The battery itself could be just fine. But, I agree\nthat there's a lot of mass and volume that could be used for other things on\na small bird.\n\nGreg KO6TH\n\n\n----Original Message Follows----\nFrom: \"Margaret Leber\" <[email protected]>\nTo: [email protected]\nSubject: [amsat-bb] Re: Future radical satellite designs\nDate: Sun, 8 Jul 2007 10:05:41 -0400\n\nOn 7/8/07, Patrick McGrane <[email protected]> wrote:\n > Hello maggie- I hate it when people snip or take things out of context.\n > Go back to the original entire email to absorb the reason. thanks,\npatrick\n\nI did read the whole thing.\n\n The challenges to amateur secondary payloads on commercial or\nmilitary spacecraft have been discussed here at length in the past.\n*My* comment was that a standalone bird *designed* without\nbattery-powered transmitters might be an interesting approach.\n\nAs it stands now we have several birds on-orbit designed with larger\nbattery systems (that have subsequently failed) that come up in\nvarious random control system states when they come out of eclipse.\nThese birds only transmit when in sunlight anyway; what if we designed\none that way on purpose? Now *that's* a \"radical satellite design\".\n\nThe payload weight that would have gone to bigger batteries to power\ntransmitters during eclipse could be used for other equipment. A\nsmaller (more reliable? certainly simpler and cheaper) auxiliary\nbattery system could keep the control systems alive during eclipse. A\nlot of work is being done with ultra-low-power processor chips for\nmobile applications these days.\n\nImagine if AO-40 had used this approach (admittedly not at all in-line\nwith the elaborate something-for-everyone AO-40 design philosophy); it\nmight still be usable. As it is, when the complex power system failed,\nwe lost the whole bird. And the only hope of recovering it is the\noutside chance that it might fail *again*.\n\n--\n73 de Maggie K3XS\nEditor, Phil-Mont Mobile Radio Club Blurb - http://www.phil-mont.org\nElecraft K2 #1641 -- AOPA 925383 -- ARRL 39280\n_______________________________________________\nSent via [email protected]. Opinions expressed are those of the author.\nNot an AMSAT-NA member? Join now to support the amateur satellite program!\nSubscription settings: http://amsat.org/mailman/listinfo/amsat-bb\n\n_________________________________________________________________\nNeed a brain boost? Recharge with a stimulating game. Play now!\nhttp://club.live.com/home.aspx?icid=club_hotmailtextlink1\n\n\n\n\n--------------------------------------------------------------------------------\n\n\n> _______________________________________________\n> Sent via [email protected]. Opinions expressed are those of the author.\n> Not an AMSAT-NA member? Join now to support the amateur satellite program!\n> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb\n> \n\n\n", "attachments": [] }