AMSAT-BB December 2007

225 participants
381 discussions

Magnetic Sail
by Mike Lemons 29 Dec '07

29 Dec '07

I was trying to think of an inexpensive way to get from LEO to HEO when I came up with the idea of using electricity to move the satellite like an electric motor. The satellite is moving through the Earth's magnetic field, so if you put a big coil on it, you should be able to time the current through the coil in order to get the satellite to move in whatever direction that you want. Then, I found that some one had already thought of it: http://en.wikipedia.org/wiki/Magnetic_sail Quoting: "By varying the magnetic sail's field strength over the course of its orbit, a magnetic sail can give itself a "perigee kick" raising the altitude of its orbit's apogee." In the simplest mode, you would energize the field to repel from the earth's pole as you pass over it. In this form of magnetic levitation, the satellite is going to want to flip over. You could compensate for this by having two coils extended on moment arms in a shallow "V" angle. See http://en.wikipedia.org/wiki/Dihedral This would prevent roll. You would need two more "wings" at a 90 degree angle to control for yaw. You might be able to get away with only three wings 120 degrees apart. I don't know how long it would take to get to HEO. That would depend on how strong of a field you could produce over how big of an area. It would work better with a lighter craft. This method of propulsion has the potential for reducing the cost of getting commercial satellites into higher orbits. Another advantage is that you can reverse the process to de-orbit your satellite at end of life. This method of propulsion might work to take you to another planet, too. It seems to me that NASA would be interested in seeing if this works. I for one wish that NASA would do more proof of concept experiments like this with alternate methods of spacecraft propulsion.

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ANS-364 AMSAT News Service Weekly Bulletins
by JoAnne Maenpaa 29 Dec '07

29 Dec '07

AMSAT NEWS SERVICE ANS-364 ANS is a free, weekly, news and information service of AMSAT North America, The Radio Amateur Satellite Corporation. ANS reports on the activities of a worldwide group of Amateur Radio operators who share an active interest in designing, building, launching and communicating through analog and digital Amateur Radio satellites. Please send any amateur satellite news or reports to: ans-editor(a)amsat.org In this edition: * 2008 Straight Key Night on OSCAR in Memory of ex-JA1ANG * AMSAT Orbital Classroom Concept Study Announced * KiwiSAT Status Update From New Zealand * AMSAT Awards * ARISS Status Report for the Week of December 24, 2007 * ANDE Satellite De-Orbits SB SAT @ AMSAT $ANS-364.01 2008 Straight Key Night on OSCAR in Memory of ex-JA1ANG AMSAT News Service Bulletin 364.01 >From AMSAT HQ SILVER SPRING, MD. December 30, 2007 To All RADIO AMATEURS BID: $ANS-364.01 You are cordially invited to take part in Straight Key Night on OSCAR 2008, sponsored by AMSAT for all radio amateurs throughout the world. This year's event will be held in memory of Haruo (Harry) Yoneda, ex-JA1ANG, a past AMSAT Director and co-founder of JAMSAT. Harry was also a keen CW operator and a past member of the First Class CW Operators Club (FOC). Participating in OSCAR SKN is fun and simple. No scoring and no need to send in a log. Just operate CW through any OSCAR, using a straight hand key, at any time between 0000 and 2400 UTC on January 1, 2008. In keeping with the friendly nature of this event, all participants are encouraged to nominate someone they worked for Best Fist. Your nominee need not have the best fist you heard, just the best of those you worked. Please send your nomination to W2RS at w2rs(a)amsat.org. Those nominated will be recognized in an AMSAT News Service bulletin, and in The AMSAT Journal. [ANS thanks Ray, W2RS for the above information] /EX SB SAT @ AMSAT $ANS-364.02 AMSAT Orbital Classroom Concept Study Announced AMSAT News Service Bulletin 364.02 >From AMSAT HQ SILVER SPRING, MD. December 30, 2007 To All RADIO AMATEURS BID: $ANS-364.02 Stefan, VE4NSA has been asked to organize and coordinate an amateur radio space communications training concept called the "Orbital Classroom". Stefan said, "Here is an opporturnity for AMSAT members to voice their needs for education. We are listening and working on this." Stefan asks interested AMSAT members to send him your answers to these questions via e-mail (ve4nsa(a)amsat.org). 1. Would you be interested in attending pre-conference courses and workshops as part of the annual meeting or at other venues? 2. Would you be willing to pay a registration fee that would cover course material, instructor cost etc.? 3. Would you be interested in receiving a certificate for ongoing education as it relates to amateur radio and satellites? 4. What topics would you like to see taught at such courses? 5. Would you be willing in helping to organize and facilitate courses (you don't have to teach for this one, just help the instructor and take care of registration, etc)? 6. Would you be willing to teach a course and if yes, on which topics? Stefan concludes, "That's a start and hopefully it sparks your interest as a participant, facilitator or instructor. As always, your opinion counts and even more your help is greatly appreciated." [ANS thanks Stefan, VE4NSA for the above information] /EX SB SAT @ AMSAT $ANS-364.03 KiwiSAT Status Update From New Zealand AMSAT News Service Bulletin 364.03 >From AMSAT HQ SILVER SPRING, MD. December 30, 2007 To All RADIO AMATEURS BID: $ANS-364.03 This week Terry, ZL3QL, President AMSAT-ZL, provided AMSAT members with a summary of the New Zealand KiwiSAT project. KiwiSAT is a Microsat scheduled for launch into a LEO, will carry FM and Linear transponders with inputs on 70 cm & 23 cm - outputting on 2 meters. A unique feature will be the on-board Small Satellite Attitude Control scientific experiment. It will also carry a special environmental global warming scientific unit. Over the years AMSAT-ZL has contributed some $10,000 to Phase 3 and UoSAT programs. Now they are getting on with completing KiwiSAT for your amateur radio enjoyment. ( See http://www.kiwisat.org ) Terry says, "We want this to be a truly radio amateur satellite and while we could get some extra sponsorship, which we will do for the launch, the satellite itself needs to be completed using amateur radio resources and amateur radio money. So far our investment is some US$15,000 cash and perhaps US$100,000 in time and effort. We have a further US$12,000 in the bank reserved towards the cost of the solar cells which are estimated to cost US$30,000." The KiwiSAT team spends a lot of time looking for economy without engineering compromise thus this is a real cost effective satellite. They have abandoned purchasing ready made modules and opted for self design and construction. In some areas we have had to use professional services such as SMD handing which is limited by our standard ham- shack tools and techniques. However we have made much of the test equipment ourselves - including the thermal vacuum chamber. To finish the satellite to flight-ready status, (less solar cells) KiwiSAT needs to raise about $10,000, which is about what we have given to other projects. So if you agree that its pay-back time, and you like what they are doing, perhaps you might like to contribute to this venture into space. You can contribute large or small, direct or via PayPal, just visit our informative website at http://www.kiwisat.org, all help is greatly appreciated. Be assured your contribution will be thankfully received and faithfully applied. Terry concludes,"Our grateful thanks to those who have already made a commitment to supporting this project. What a great time to help and what a great Yuletide gift to a worthy cause." [ANS thanks Terry, ZL3QL for the above information] /EX SB SAT @ AMSAT $ANS-364.04 AMSAT Awards AMSAT News Service Bulletin 364.04 >From AMSAT HQ SILVER SPRING, MD. December 30, 2007 To All RADIO AMATEURS BID: $ANS-364.04 Bruce Paige, KK5DO, AMSAT Director Contests and Awards has issued the last awards for 2007. We would like to welcome the following to the satellite community. They have made their first satellite contact and are now members of the AMSAT Satellite Communicators Club: Jeremy Ramirez KB9QIC Charles Doolittle N1SPX Jose Vitor Toste CU3EQ AMSAT Communication Achievement Award John Henderson N4NAB, #456 Charles Doolittle N1SPX, #457 South Africa AMSAT Communication Achievement Award John Henderson N4NAB, US115 Charles Doolittle N1SPX, US116 To see all the awards visit http://www.amsat.org. [ANS thanks Bruce, KK5DO for the above information] /EX SB SAT @ AMSAT $ANS-364.05 ARISS Status Report for the Week of December 24, 2007 AMSAT News Service Bulletin 364.05 >From AMSAT HQ SILVER SPRING, MD. December 30, 2007 To All RADIO AMATEURS BID: $ANS-364.05 1. ARISS Contact with Russian School The ARISS contact was not successful with the 15 Korolev City School in Korolev, Russia on Thursday, December 27 and will be rescheduled. Fifth graders will speak with flight engineer Yuri Makenchenko, RK3DUP. 2. ARISS International Team Meeting Held The monthly ARISS teleconference was held on Tuesday, December 18. The topics discussed included the 2008 Face to Face Meeting to be held in Moscow, Russia, the progress being made on SuitSat-2 and the Kenwood radio software reload status. Minutes will be posted to the ARISS Web site in the near future. 3. Astronaut Gives Talk on ARISS at AMRASE Conference The first AMRASE International Aerospace Research Conference was held on December 8 in Rio de Janeiro. Brazilian astronaut Marcos Pontes was one of the speakers at the meeting. Pontes gave a presentation on his training and his participation in the Centenario Mission onboard the ISS. He also talked about the importance the ARISS program plays in the education of youth. See: http://www.amrase.org/english.html [ANS thanks Carol, KB3LKI for the above information] /EX SB SAT @ AMSAT $ANS-364.06 ANDE Satellite De-Orbits AMSAT News Service Bulletin 364.06 >From AMSAT HQ SILVER SPRING, MD. December 30, 2007 To All RADIO AMATEURS BID: $ANS-364.06 Henk, PA3GUO reminds everyone of the special ANDE de-Orbit AWARD available for everyone who makes a QSO via ANDE or receives telemetry during its final days in space. Bob, WB4APR, will set the official date/time of de-orbit. E-mail a copy of your final ANDE packets to Henk at pa3guo(a)amsat.org. ANDE was no longer copied on December 25, 2007. Mike, DK3WN reported the last packet from ANDE was received by by JA0CAW on December 24, 2007 at 22:27 UTC: Fm ANDE-1 To APRS1 Via SGATE <UI pid=F0 Len=72 >[22:27:08] :BLN1ANDE :ANDE-1 only wakes up 1 of evry 15s for users. Pse conserve. Fm ANDE-1 To BEACON <UI pid=F0 Len=39 >[22:27:43] T#001,145,132,135,135,137,10101111,000 [ANS thanks Henk, PA3GUO and Mike, DK3WN for the above information] /EX In addition to regular membership, AMSAT offers membership in the President's Club. Members of the President's Club, as sustaining donors to AMSAT Project Funds, will be eligible to receive additional benefits. Application forms are available from the AMSAT Office. 73, This week's ANS Editor, JoAnne Maenpaa, K9JKM K9JKM at amsat dot org

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Re: RF Modules
by John Marranca, Jr 29 Dec '07

29 Dec '07

Happy New Year Everyone: I think it was made pretty clear in the last incarnation of this discussion that the real difficulty is not in the build, but in the delivery. VK4TEC has a good idea/concept: A simpler trasceiver. I agree. It goes along in spirit with the fact that Oscar 1 was built for $26 in 1961 (ARRL; "The Radio Amateur's Satellite Handbook, Page 1-6). But now imagine today...with a $26 satellite...paying n-thousands of dollars to launch it. Perhaps a venue that might be exploited if it hasn't already, is asking NASA if it is possible to bring one up with them when a Shuttle goes to the ISS. The problem that I see with that is that the orbit is WAY TOO LOW for that bird to be practical for very long. Think ANDE-1...or the upcoming Delfi-3 which is another temporary satellite. Anyway...what if partnerships with any of the Military Academies...or Universities with programs similar to this (such as Kentucky State's KySat Project) could be worked out? AMSAT ideas or concepts and build team partnerships with students, etc...but with a chance for greater funding available for a potential launch? Food for thought.... John KB2HSH -- _______________________________ John Marranca, Jr PBX Technician/Shop Steward CWA Local 1122 BN Systems, Inc Orchard Park, NY (716)972-2006

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RF Modules
by Andrew Rich 29 Dec '07

29 Dec '07

I wonder if anyone has consdered RF modules for a satellite. I have been playing with a module called "Easy Radio" It takes care of the pre-amble, bit flipping and CRC. Freq = 433.900 MHz They put out in the order of mW, but I put a 30 watt amp on the end and wow ! The data burst is 180 characters max, and it takes around 25ms to send. These are cheap, they cost around $80 for a full data transciever. It would eliminate a whole lot of stuff on a board. I used them for a glider tracker. Anyway here are some photos of what I am talking about. http://www.tech-software.net/glider_tx.php ---------------------------------------------------------------------------- Andrew Rich VK4TEC

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ANDE: results of the de-orbit Event & AWARD details
by Henk, PA3GUO 29 Dec '07

29 Dec '07

Dear all, ANDE (NO-61) has de-orbited last week - after spending ~370 days in space. During its short life many radio amateurs used the satellite. Most of them found it initially a challenge to hear the downlink. Yet, over time more and more stations joined. Many stations improved their antenna systems and got to hear ANDE. In the very last days, while the passes got even shorter, there were up to 8 stations actively digipeating via the satellite in a single pass. We have seen more and more HAMS enhancing their satellite radio-stations and set-up a SatGate (= automated internet forwarding of all data received on 145.825 MHz, the 2mtr APRS downlink of multiple satellites). During December up to 78 stations worldwide non-stop forwarded data they received ! A great achievement, providing value also after ANDE. Radio amateurs have proven to be able to get their act together on very short terms and set up dedicated digital communication links using very small satellites. Note that all of this has been fully operational for a period of 4 weeks non-stop. All systems on-board ANDE have been functioning fine until de-orbit. We did not observe any major deviation in the telemetry data (eg in temperature). Just a few hours before the decay in the morning of Dec 25, JA0CAW received his last telemetry packet (2007/12/24 22:27:43) and W6MSU was still able to digipeat (2007/12/24 21:14:13). That whole last day of Dec 24 many stations around the world used the tiny APRS satellite... which was running its entire life on batteries only ! ANDE has successfully completed its mission and served as a great APRS satellite. Now - back to the competition & fun part: the AWARD ! ===================================================== Many radio amateur stations from around the world participated in the special ANDE de-orbit event and have received and forwarded valuable telemetry of the satellite during its last days in space. For everyone that participated we have made available a special AWARD. Everyone that made QSOs via ANDE or received telemetry during its final 10 days in space can submit his/her achievements and apply for the AWARD. On the AWARD your callsign and achievements will be mentioned: ANDE APRS QSOs: 1 point for each 2 way APRS QSO in the period Dec 15-24 Example: 00:01:31:24 : KB1GVR]APU25N,ANDE-1*,qAO,K8YSE-6::KC2PCR :GA Doug 00:01:31:42 : KC2PCR]APRS,ANDE-1*,qAO,KB\2CEV::KB1GVR :G'Afternoon Mark ;) ANDE Telemetry reception (in total 55 telemetry points can be achieved): 10 points for telemetry packets of Dec 24, 2007 9 points for telemetry packets of Dec 23, 2007 8 points for telemetry packets of Dec 22, 2007 7 points for telemetry packets of Dec 21, 2007 6 points for telemetry packets of Dec 20, 2007 5 points for telemetry packets of Dec 19, 2007 4 points for telemetry packets of Dec 18, 2007 3 points for telemetry packets of Dec 17, 2007 2 points for telemetry packets of Dec 16, 2007 1 point for telemetry packets of Dec 15, 2007 Of course your participation is what counts most, not the final score ! We ask 4 euro for submissions in Europe and 6 euro outside Europe. This is only for printing & shipping the awards, any surplus will be donated to an AMSAT satellite project. For all details on submission/payments/status etc: http://www.ande-deorbit.com On this website we have maintained an overview of all participating stations that forwarded data. There is also an overview of all the telemetry since Nov 14, when we started this event. A draft version of the award itself can been pre-viewed as well ! Have a look yourself ! Finally we would like to thank all radio amateur stations world-wide that have contributed and participated in the event. Without your help this would not have been possible. It has really been a lot a fun ! Looking forward to your submissions & feedback on the website ! 73's Mike, DK3WN Henk, PA3GUO http://www.ande-deorbit.com

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435 offset yagi phasing
by Andrew Rich 29 Dec '07

29 Dec '07

Hi I have had good success with just one yagi of an offset crossed array I am building. http://wa5vjb.com/yagi-pdf/cheapyagi.pdf I will add the other elements shortly. I am not ready to tackle the phasing part. I hope I have this right. 1. The yagi's are offset, by 90 degrees so that is the offset already. 2. Both yagis's should then have the same length of coax coming from each one. 3. Both yagi's will require a 1/4 wavelength of 75 ohm coax for each feed. 4. Remebering that the velocity factor is 2/3 in coax cable, or the speed of light 200 instead of 300. 5. Both 75 ohm feeds then join at a tee, the result of the 50 ohm antenna and 70 ohm feed giving around 120 ohm 6. By tee'ing the two together, this should present around 50 ohm, required for the main feedline. Does that sound right ? ( 200/435 MHz ) /4 = 11.49 cm for each feed to the tee junction of 75 ohm cable. ---------------------------------------------------------------------------- Andrew Rich VK4TEC

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Yaesu FT-897 and HRD satellite tracking problem
by Dave Matthews 29 Dec '07

29 Dec '07

Merry Christmas everyone. And apologies since I expect the question I ask here is old hat, but I've researched everywhere and still can't find a solution that works: When using the Ham Radio Deluxe satellite tool for satellite tracking with automatic Doppler shift adjustment, I have a periodic 'polling?' noise issue with my Yaesu FT-897, the same as I had last field day with HRD and a FT-857. There is a periodic noise burst that coincides with the black square animation on the upper left of the satellite tracking tool screen. This noise burst makes it impossible to listen to very faint signals, and is annoying as all get out when waiting for a satellite to come into range. FM and SSB modes. I want to use the HRD program with its built in Doppler shift tracking, but it is unusable -for me- as a result of this problem. During Field Day the FT-857 rig was controlled by a laptop, and yagis were about 20' away pointing at the sky. This current FT-897 setup is on a desktop style office computer into eggbeaters warming the clouds. My CT-62 interface cable is shielded, but the shield was not connected! I tied the shield to ground, no difference. The RS-232 extension cable used is also shielded. Grounds are good in this upstairs office shack but I am about 12' above the ground rod. Trying different grounding makes no difference. Ferrite Beads on the comm cable, looped multiple times through the beads, etc. makes absolutely no difference. And I just tried a USB to serial interface replacing the RS-232 from the computer, no difference. So I've shielded and beaded and grounded and experimented to no avail. This is a really annoying problem, and I feel there must be something elementary that I am missing either in the FT-897 setup or in HRD. I expect it is a Yaesu FT-897/857 problem, but again it may just be a setup issue. Any response is appreciated, Dave KI4PSR

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AO-51 quick update
by Andrew Glasbrenner 28 Dec '07

28 Dec '07

Just a quick note that we will be shutting off the L band uplink to the BBS on AO-51 tomorrow for approximately 24 hours. We need the SQRX to do a quick RF survey for another project. The BBS should be accessible again on Sunday. We are now on the quick slide into our first full sun period starting Jan 4, 2008, and things may get a little hectic as we try to reduce the impact of the increased heat. A byproduct of this is the available downlink power is increasing rapidly, so the satellite should continue to become easier to hear this week. We may also ask for help with telemetry checks between morning and evening passes over the command stations. Thanks for your understanding. 73, Drew KO4MA AMSAT-NA VP Operations

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Re: Sun shadow for True North
by Tony Langdon 28 Dec '07

28 Dec '07

At 11:14 AM 12/29/2007, Dave Guimont wrote: >>>A vertical rod about 4' long (plumb it, or use a level) will have the >>>shortest shadow at noon. > >I should have said "near noon"..... You still need to know "when near noon" to within 5 minutes to get the required accuracy. :) 73 de VK3JED http://vkradio.com

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Re: Sun shadow for True North
by Tony Langdon 28 Dec '07

28 Dec '07

At 05:29 AM 12/29/2007, Dave Guimont wrote: >A vertical rod about 4' long (plumb it, or use a level) will have the >shortest shadow at noon. Not necessarily. Ignoring DST, local solar noon can occur anywhere within a window of around 1 hour (give or take, depending on the exact borders of your local time zone), because each time zone is approximately 15 degrees wide (there are local variations that take the official zones beyond the 15 degree nominal zones). For example, here in Melbourne, local solar noon usually occurs around approximately 02:15 - 02:20 UTC (12:15 - 12:20 standard time or 13:15 - 13:20 DST). In Brisbane, it occurs before noon AEST, despite both cities being in the same time zone. Using the "shortest shadow at noon" method, you can have an error of up to 10 degrees (now THAT would ruin the performance of your high gain antenna!). Here, it would be around 4-5 degrees, if one was ignorant of the actual time of solar noon. The moving shadow to find the East - West line is a much better and MUCH more accurate idea. 73 de VK3JED http://vkradio.com

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AMSAT-BB December 2007