August 2008 - AMSAT-BB - mailman.amsat.org

Re: AMSAT UK P3E Lecture HEO vs GEO. and AMSAT-NAPriorities
by Ken Ernandes 12 Aug '08

12 Aug '08

Overruled? Interesting... What I've see in this discussion on the HEO issues appear to be more speculative than based on fact or any official announcement from the AMSAT-NA BOD. I personally would consider it premature to summarily declare the discussion closed. We could, perhaps put it on hold until the AMSAT-NA BOD provides current status. Perhaps it would be better to refrain from inflammatory statements with "absolutes" before we have an official statement on the HEO subject. 73, Ken Ernandes N2WWD -----Original Message----- >From: k7zt(a)suddenlink.net >Sent: Aug 12, 2008 12:31 PM >To: Andrew Glasbrenner <glasbrenner(a)mindspring.com>, amsat-bb(a)amsat.org, "John B. Stephensen" <kd6ozh(a)comcast.net> >Subject: [amsat-bb] Re: AMSAT UK P3E Lecture HEO vs GEO. and AMSAT-NAPriorities > >NOTICE to ALL HEO proponents: > >YOU HAVE BEEN OVERRULED, dialog is finished, so stop it. > >---- Andrew Glasbrenner <glasbrenner(a)mindspring.com> wrote: >> At this point AMSAT is going to take the first thing that gets us above LEO >> that we can afford. If that is HEO, so be it. If it is GEO, it's GEO. Being >> divided and fussy over the details only detracts from the effort. We are >> basically beggars in the launch market, and we all know the saying about >> beggars and choosers. The mission is to provide long access time satellite >> comms on a daily, then 24/7 basis. How that happens is yet to be >> determined... >> >> Sorry to be so brief but I have a lot going on with my day job at the >> moment. There will be more information forthcoming. >> >> 73, Drew KO4MA >> >> ----- Original Message ----- >> From: "Joe Westbrook" <k7zt(a)suddenlink.net> >> To: "John B. Stephensen" <kd6ozh(a)comcast.net>; <amsat-bb(a)amsat.org> >> Sent: Tuesday, August 12, 2008 8:44 AM >> Subject: [amsat-bb] Re: AMSAT UK P3E Lecture HEO vs GEO. and >> AMSAT-NAPriorities >> >> >> > John: >> > That certainly is one approach, I'm not saying that there is anything >> > wrong >> > with that, it's just a change in the stated goals of Eagle. >> > The leadership needs to get in front of this and announce this is a >> > significant shift in organizational strategy if indeed that is the plan. >> > >> > At they same time for the sake of honesty they should probably tell folks >> > that this will end AMSAT-NA sponsorship of an HEO (Molmiya Orbit) >> > anytime soon or even in their lifetime ;-/ >> > >> > - Joe >> > >> > ----- Original Message ----- >> > From: "John B. Stephensen" <kd6ozh(a)comcast.net> >> > To: "Joe Westbrook" <k7zt(a)suddenlink.net>; <amsat-bb(a)amsat.org> >> > Sent: Tuesday, August 12, 2008 6:05 AM >> > Subject: Re: AMSAT UK P3E Lecture HEO vs GEO. and AMSAT-NA Priorities >> > >> > >> >> > >> >>> It appears that leadership is allowing realities of >> >>> a rare, expensive launch opportunity drive the mission rather than the >> >>> mission driving the launch method, it's a bit like the tail wagging the >> >>> dog >> >>> don't you think? >> >>> >> >> AO-40 was the case of a rare launch opportunity driving the mission. The >> >> AMSAT BoD has stated that the purpose of creating a relelationship with >> >> Intelsat would be to provide multiple launch opportunities. It seems to >> >> me >> >> that finding an affordable launch method should be the first step rather >> >> than the last step. >> >> >> >> 73, >> >> >> >> John >> >> KD6OZH >> >> >> >> >> > >> > _______________________________________________ >> > Sent via AMSAT-BB(a)amsat.org. Opinions expressed are those of the author. >> > Not an AMSAT-NA member? Join now to support the amateur satellite program! >> > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >> > >_______________________________________________ >Sent via AMSAT-BB(a)amsat.org. Opinions expressed are those of the author. >Not an AMSAT-NA member? Join now to support the amateur satellite program! >Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb

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Re: way of satellite recovery?
by Bob Bruninga 12 Aug '08

12 Aug '08

> Somebody can I'm sure post the costs of the Shuttle > Missions that have recovered/repaired satellites. I think, that the only externally deployed, autonomous Amateur Satellite ever deployed and later recovered and returned to Earth was PCSAT2. Since PCSAT2 was attached to the outside of the ISS and although it floated in space (but held with a strong grip by an astronaut until affixed to a handrail), AMSAT denied the request for an OSCAR number. But otherwise it was completely atonomous payload. We think it can be claimed as the only amateur satellite returned to earth. Though of course, that can be argued for ever... Bob, WB4APR

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Fwd: Information Request
by Martha 12 Aug '08

12 Aug '08

Would someone help Shayne? ---------- Forwarded message ---------- From: AMSAT Website <www(a)amsat.org> Date: Mon, Aug 11, 2008 at 1:22 AM Subject: Information Request To: martha(a)amsat.org This message originated from the AMSAT website Sender: VK4HJS SHAYNE Email: vh5hjs(a)bigpond.com Host: CPE-60-229-61-191.nsw.bigpond.net.au Subject: Information Request Message: I am having endless trouble attempting to get my computers (3) to recognise my YAESU Computer Controller GS-232B. After following all of the instructions from the manual included with the GS-232B. I have used 3 Windows operating systems, XP, ME and Win98 Would anybody be able to help as Yaesu hasn't been any help whatsoever, saying that it works but neglect to tell me how they got it operational. Thanking you for your speedy reply JR Shayne (end of message) Problems with this message? Email to w2gps(a)amsat.org -- 73- Martha

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SSB Preamp
by Peter 12 Aug '08

12 Aug '08

Hi, Is anyone using a SSB SP-7000 preamp and an Icom 910H powered via direct feed from the coax. I am not able to turn the preamp on with this method, I set the menu for the preamp and the front panel; it recognizes a preamp but it's not working, any ideas? 73 Peter WB2OQQ

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Fw: For Sale "TrakBox" Satellite tracker --- REDUCED Price
by Robert Felt 12 Aug '08

12 Aug '08

SOLD as of 8-11-08 @ 1807EDT ----- Original Message ----- From: Robert Felt To: amsat-bb(a)amsat.org Sent: Monday, August 11, 2008 6:11 PM Subject: For Sale "TrakBox" Satellite tracker --- REDUCED Price For Sale - REDUCED PRICE -- $100. "TrakBox" Satellite tracker, antenna rotor controller for stand alone operation. (JARL design, TAPR kit) The trakbox is a self-contained, stand-alone rotor/radio control for use with your satellite stations. Select the satellite you wish to track from a front panel control and the TrakBox will steer your antennas in both azimuth and elevation to track the selected satellite when it is or above your horizon. In addition, if you have a radio with a computer interface, the TrakBox will tune your transmitter and receiver and correct them for doppler shift. TrakBox is set up to directly interface to Kenpro, Emmoto, and Yaesu dual-axis rotators which include a computer interface. Trakbox includes a serial port to allow you to set the real-time clock (which is battery backed), your station location (latitude, longitude and elevation) and the keplerian elements for the satellites you are interested in (up to 40 satellites may be loaded, and the elements may be uploaded in ASCII in either the AMSAT or NASA formats). A two-line LCD display is updated every second, showing the azimuth and elevation of a satellite, along with the satellite ID and GMT. I built this kit from TAPR back in the late 1990's. It provided excellent service. Still works great. See Complete description and docs at TAPR web page: http://www.tapr.org/kits_trakbox.html Now asking only $100. (was $130). Will take PayPal. 73 --- //Bob// Robert Felt --KB5YZG-- 1403 5th Ave West Hendersonville, NC 28739 tel: 828-696-4103 email: kb5yzg(a)amsat.org

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AMSAT HEO design evolution (longish)
by G0MRF＠aol.com 12 Aug '08

12 Aug '08

Given the understandable negative content of the posts recently regarding the AMSAT HEO satellite debate, perhaps it's time to return to basics and ask some fundamental questions about the way we design satellites and fund their launch. The problem: AMSAT High Earth Orbiting satellites have historically had a mass between 150kg for P3 and 650kg+ for AO-40 and at 30,000 Euros per kg, we do not have the resources to self finance the launch costs of 4.5 million (30k x 150) to 15 million Euros to launch. However, AO-40 was probably a 1-off and will never be repeated. So let's say 4 - 5 million. The way forward? 1) Raising the funds for the standard launch cost of the typical AMSAT HEO is beyond us. So other external funding solutions are needed either by providing a service which is paid for. - An example of exploring this route is the AMSAT NA proposed Advanced Communications Project via Intelsat. A second approach, is to include commercial payloads within the AMSAT spacecraft, or perhaps including AMSAT 'functionality' within other commercially or educationally funded spacecraft. Again, there are examples of this approach for LEOs. Delfi C3 is one success story. Also, and had it worked for more than a few orbits the ESA Education department / SSETI Express XO-53 was another. But at HEO the opportunites are very rare indeed, the only project currently being persued is the ESA ESEO educational mission with AMSAT UK providing a U/S transponder as part of a redundant communications system for the spacecraft. As we have been reminded in the past few days, self funding never worked before and it wont work in the future. I feel some sympathy for the AMSAT NA board who have an apparently impossible task to fulfil, but their enthusiasm to elicit support has let expectations exceed funding ability. - The response ha s been vocal. But at least they are trying. Finally on the funding issue, what have we done in the last 8 years? We've had the Eagle fund. We've had the successful AO-51 fund raising campaign, but really, since the launch of AO-40 in November 2000 we haven't saved for this 'HEO' eventuality. If we are ever going to replace spacecraft in the future, fund raising needs to be more sustained and less impulse led. We have little to show for the last 8 years. 2) There is however another option which may be self financing. A fundamental spacecraft redesign to reduce the mass to a figure we can afford to launch. Over the last 25 years, the mass of a P3 spacecraft has remained fairly constant. About 90kg of structure and payload with an additional 60kg of bi-propellent fuel. There are probably ways of trimming this back substantially. In LEO sat design we have seen a reduction in size from 400kg to the SSTL microsat of about 120kg in the 1980's. These days the SSTL 'microsat' has evolved down to 3 - 5kg. with projects like the NASA Nanosail design. But no such revolution has taken place in HEO satellites So, a few possibilities. You can probably think of more...... a) The 60kg of fuel has been needed to raise perigee and increase inclination from a typical geostationary transfer orbit. But there have been orbital change manoeuvres that have not gone to plan e.g. AO-10 and AO-40, but those satellites have still given us usable communications. Do we need all 60kg? How about raising the perigee to give a long life and a slight increase in inclination to get us out of the GTO belt around from around 7 degrees to 15 degrees? I wonder what the saving is there, 400 Newton motor down to 50 Newton motor. Fuel from 60kg down to 15kg? Saving = 45 + 5kg = 1.5 million Euros? OK the figures are guesswork, but there must be savings. b) Spacecraft design. During our time with P3 spacecraft, we have seen transponder power change dramatically. I recall the first few days of AO-40 when I heard the 2m beacon stronger than many local FM stations. But then it used a 300 Watt BLF278 type device and was designed to give a huge signal. Equally, I also recall receiving a worked all continents satellite award for QSOs I made on the experimental AO-13 mode S transponder. That was 1 Watt (max) into a 5 turn helix on 2400. So, in the future, do we need 45 or 50 Watts of power in a 100kHz wide transponder? After all, if there are fewer amateurs, we can use less bandwidth saving power and mass in the process. 8 Watts and 50kHz? A consequence of such a design change would require a groundstation with more than a patch antenna to pick up the signal. But is that unreasonable, dishes are cheaper than launches. c) Two final thoughts. Firstly, isn't the world moving away from metal structures to carbon and ceramic composites. Mass saving perhaps. Secondly, I don't think AMSAT with it's limited resources can afford to put spacecraft into orbit that will fail the moment the batteries die. Let's not dwell on the excellent Delfi example, but instead look at the Intelsat spacecraft. Is it not the case that they have a 10 year lifespan which is limited by stationkeeping fuel? While they operate 24/7 the power comes from the solar cells. The batteries are used only in eclipse. With our P3 designs, as I understand them, the spacecraft can not function on solar cells alone. Unfortunately, the advantage of our chosen HEO orbits also mean that the batteries on a P3 satellite go through a couple of eclipses a day. As battery life is proportional (or worse) to depth of discharge of the batteries, it's not surprising that most AMSAT spacecraft suffer battery failure. But with limited funds we really need to design in a mode so that 5 years on, the batteries can be switched out of circuit and a sensible geometry of solar panels can continue to provide some daylight only functionality. Conclusion: Funding campaigns need to run over several years within a rolling plan to supply launch funding. Designs need to evolve to include new technologies. Mass reduction = lower launch cost should be near the top of the list. With fewer amateurs, and modern digital modes we need less bandwidth. It is not unreasonable for an AMSAT member to need a moderate size of antenna to work an HEO. So, lower power in space. Lifespan needs to be increased and with HEO that means battery failure should be anticipated and mitigated in the design. A daylight operating spacecraft is better than no spacecraft at all. Thanks..........a quiet day here! David Could we do HEO within a 50kg budget? = 1.5million Euros spread over a 10 year lifespan?

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For Sale "TrakBox" Satellite tracker --- REDUCED Price
by Robert Felt 11 Aug '08

11 Aug '08

For Sale - REDUCED PRICE -- $100. "TrakBox" Satellite tracker, antenna rotor controller for stand alone operation. (JARL design, TAPR kit) The trakbox is a self-contained, stand-alone rotor/radio control for use with your satellite stations. Select the satellite you wish to track from a front panel control and the TrakBox will steer your antennas in both azimuth and elevation to track the selected satellite when it is or above your horizon. In addition, if you have a radio with a computer interface, the TrakBox will tune your transmitter and receiver and correct them for doppler shift. TrakBox is set up to directly interface to Kenpro, Emmoto, and Yaesu dual-axis rotators which include a computer interface. Trakbox includes a serial port to allow you to set the real-time clock (which is battery backed), your station location (latitude, longitude and elevation) and the keplerian elements for the satellites you are interested in (up to 40 satellites may be loaded, and the elements may be uploaded in ASCII in either the AMSAT or NASA formats). A two-line LCD display is updated every second, showing the azimuth and elevation of a satellite, along with the satellite ID and GMT. I built this kit from TAPR back in the late 1990's. It provided excellent service. Still works great. See Complete description and docs at TAPR web page: http://www.tapr.org/kits_trakbox.html Now asking only $100. (was $130). Will take PayPal. 73 --- //Bob// Robert Felt --KB5YZG-- 1403 5th Ave West Hendersonville, NC 28739 tel: 828-696-4103 email: kb5yzg(a)amsat.org

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DO-64
by WILLIAMS MICHAEL 11 Aug '08

11 Aug '08

I did get two good descending passes today at 14:16 and 15:51 UTC. The 14:16 UTC pass was at 10 degrees maximum elevation and I was able to hear myself through the transponder satisfactory. My antennas are only 2.4 meters above ground so reception is blocked by buildings and trees. The pass was good enough for a QSO on CW. On the 15:51 UTC pass, I could hear the 200 mW transponder from just after AOS to about 3 degrees from LOS. When Delfi was above the ground objects, I could reduce my output to 2 watts and still return an excellent signal from Delfi Down link antenna is 14 ele. KLM LHCP Up link antenna is 11 turn helix RHCP Mike Williams K9QHO AMSAT 33589

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Transcontinental from Scotland (+ spam troubles)
by John Mock KD6PAG 11 Aug '08

11 Aug '08

[It appears that my first attempt at posting this failed, perhaps due to problems i'm having with a spammer using a variant of my e-mail address.] I'm heading out tomorrow for Scotland. Given the AO-51 schedule, it does not appear that i'll be able to work very far down the East Coast before i get to the Shetlands, as the relevant SO-50 passes will be past my bedtime. I may try to work some continental stations and will post an update if/when i have Internet access (and something to say). I look forward to working people from the Shetlands and then from mainland Scotland after the change to mode J-FM (VU mode). 73's and best of luck! -- KD6PAG P.S. Some spammer(s) are forging a variant of my e-mail address and i had to de-register my home computer's 'fdns.net' address, in the public interest (e.g. so spam might be rejected more quickly). Please use 'dyndns.org' in place of 'fdns.net', or better yet, use the links from QSL.net to access my local web resources.

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Re: DO-64 observation
by Bob Bruninga 11 Aug '08

11 Aug '08

> As Delfi-C3 goes over the earths poles, > it flips itself 180 degrees in Z axis > > Are you saying it has an active attitude control > ... Or is the satellite rotating with a period > equal to that of its orbit? Actually it is two rotations per orbit. To people on Earth it is "horizontal" over the equator and vertical over the poles and does a full revolution over half an orbit. A benefit is that it prevents any side from facing the sun for more than 12 minutes at a time... and also lets you plan on antenna orientation everywhere. Bob, WB4APR

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