- Eagle (INACTIVE) - mailman.amsat.org

AMSAT award
by Robert McGwier 28 Oct '06

28 Oct '06

It pleases me greatly to announce that Eric Ellison has been presented with an award from AMSAT. It is sometimes easy to take for granted what seems to many to be a small thing. In the case of AMSAT, Eric's work made virtual meetings not only possible but easy. AMSAT has literally run its Eagle project using VOIP facilities which Eric set up on behalf of the technical groups active today in amateur radio in satellites, technology, and in particular software defined radio. AMSAT and TAPR both recognize Eric's work, AMSAT with the award and TAPR membership with Eric's election to its board of directors. Someday Eric's TEAMSPEAK server will be universally recognized for the spectacular impact it has had and will continue to have. Eric, the award is in the mail from the AMSAT office along with a gift membership in AMSAT for a year. Jim Sanford, Eagle project manager, and I and the entire organization give you our thanks for your generosity and help. 73's Bob McGwier N4HY -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair "You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat." - Einstein

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CONGRATULATIONS TO N2UO
by Robert McGwier 24 Oct '06

24 Oct '06

I know all of the Eagle designers will join me in congratulating Marc Franco, N2UO on his being granted permanent residency here in the U.S. His skills represent a major asset to Eagle, Lintech, and the U.S. [in that order ;-)] and it is good when the immigration office does something sensible for a change. CONGRATULATIONS Marc! Bob N4HY -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair "You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat." - Einstein

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Eagle Team Leadership change announcement
by Jim Sanford 22 Oct '06

22 Oct '06

Team: I wish to announce that Bob Davis, KF4KSS, has assumed the role of Structure and Mechanical Team Leader. Bob has experience in finishing and integrating AO-40, and is employed in the aerospace industry, where he has acquired significant experience since the AO-40 campaign. Dick Jansson, WD4FAB, has led this team for several years and is not going away. Dick will support Bob as a team member, focussing on structural team coordination and thermal design and analysis. Dick told me this afternoon, "I'm really excited to see the new blood coming in and assuming leadership roles. I look forward to supporting Bob and being on his team." I thank Dick for all that he has done for AMSAT and WILL do for Eagle and AMSAT. Thanks for all you've taught us. Bob, thanks for stepping up to the plate. I look forward to working with you, and I look forward to learning from you. Thanks and very 73 to all, Jim wb4gcs(a)amsat.org Eagle Project Manager

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AVP -Engineering team
by Robert McGwier 21 Oct '06

21 Oct '06

I have asked the following folks to be AVP for Engineering. Jim Sanford as Eagle project manager Lou McFadin as Manned Space chief engineer Bob Davis as lab director and spacecraft integration leader Please add them to the officers mailing list if they are not already on it please. Welcome and thank all of them for their continued great service to AMSAT. Bob N4HY -- AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL, TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair "You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat." - Einstein

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S1 downlink coordination and interference mitigation
by Howard Long 18 Oct '06

18 Oct '06

Folks, Coincidentally at the Symposium, Graham Shirville spent some time coordinating proposed frequencies to some satellites, including Eagle, and after a suggestion I had from from Drew KO4MA, I reiterated to Graham that it may be advantageous to propose S1 frequencies right down at the bottom 1MHz of the 2.4GHz satellite allocation. 802.11 specifies a 1MHz guard band at 2400 to 2401MHz for regulatory OOB emission reasons. Signals +/-11MHz from the centre must be at least 30dB down from the carrier. Channel 1 is at 2412MHz. Taking into account Doppler, the recommended S1 coordinated frequencies will be at the bootom end of 2400MHz without the possibility of OOB emissions on Earth due to Doppler. 73, Howard G6LVB

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Service class names
by Jim Sanford 17 Oct '06

17 Oct '06

Team: A few days ago, I made a proposal for naming Eagle's communications services and solicited comments. I received many good comments. I really think it important that we have unambiguous service class names. Based on all the comments, I propose: U/V "linear" L/S "linear" Text messaging Low Rate ACP High Rate ACP While I'd prever something less ambiguous than "linear", our customers seem to understand that "linear" means SSB/CW/PSK31/SSTv . . . . etx. Any strong objections to this? If not, I'll get the announcement on AMSAT.org changed. It's time to get precise. Thanks & 73, Jim wb4gcs(a)amsat.org

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Module Paper
by Dick Jansson-rr 15 Oct '06

15 Oct '06

I have been asked if I can provide a copy of the module paper of mine that was so skillfully presented by Bob Davis at the recent AMSAT Space Symposium. This is for those of you who were not able to be at the symposium and receive the Proceedings. This paper is now available on Eaglepedia at: <http://www.amsat.org/amsat-new/eagle/EaglePedia/index.php/Module_Design> http://www.amsat.org/amsat-new/eagle/EaglePedia/index.php/Module_Design Dick Jansson --------------------------- <mailto:rjansson@cfl.rr.com> rjansson(a)cfl.rr.com ---------------------------

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Module Temperatures
by Dick Jansson-rr 14 Oct '06

14 Oct '06

Last evening I tried to convey the concept that the critical-command modules needed to be of low-power design to insure their operability during the occasional rather lengthy eclipse cooling of the spacecraft. My message apparently did not sink in. John reports that his design of such a U band receiver would be dissipating some 3.5W due to its bullet-proof nature against 3rd-order IM products needed for protection on the U band. If we go forward with such a module of that nature, it will need to have thermal control tapes on it to provide a mean emittance of about e=0.45. In a 3 hour eclipse we can expect to see spaceframe temperatures down to -100°C (173K) or lower. With such an environment John's module would be expected to see temperatures down to at least -44°C, which is a bit frosty for electronics that are expected to provide the critical services of commanding the spacecraft. Such operating temperatures are not felt to be advisable for that service. If John's module were of the 1W category, temperatures of the receiver could be expected to be in the range of -15°C to -20°C which would be more operable for the service. The above numbers are, of course, based on estimates which will be confirmed after we have the new spaceframe fully designed and analyzed. The "warmer" temperatures of the lower power modules are those that have been experienced and measured by telemetry from AO-10 and AO-13. These projections are thus based on 25 years of experience in these design concepts. Dick Jansson --------------------------- <mailto:rjansson@cfl.rr.com> rjansson(a)cfl.rr.com ---------------------------

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ARRL Letter Mentions Eagle
by JoAnne Maenpaa 13 Oct '06

13 Oct '06

The ARRL Letter, Vol. 25, No. 41 released on October 13, 2006 mentions Eagle. Here is a copy of the Eagle item for those who don't get this via ARRL channels ... -- 73 de JoAnne K9JKM k9jkm(a)amsat.org ==>AMSAT'S PROJECT EAGLE SATELLITE SHIFTS DIRECTION AMSAT-NA has announced it's revamping the design of its high-Earth orbit (HEO) Project Eagle satellite, currently in the development stages <http://www.amsat.org/amsat-new/eagle/>. The next generation satellite will take maximum advantage of software-defined transponder (SDX) technology to offer a broader range of easily accessible Amateur Radio payloads. The AMSAT Board of Directors okayed the Eagle upgrade plans during the 2006 AMSAT-NA Space Symposium and Annual Meeting held October 6-8 in San Francisco. Eagle Project Manager Jim Sanford, WB4GCS, outlined the changes at his Space Symposium forum October 7. "The structure which we have been presenting for several years is not going to meet our mission needs," Sanford explained. "We have moved on to a later structure." Under the new plan, Sanford says, Eagle's communications payloads will include a mode U/V linear transponder for SSB, CW and other modes. A second SSB/CW transponder will uplink on L band (1.2 GHz) and downlink on S1 band (2.4 GHz). Both would be usable over 75 percent of the satellite's orbit by an AO-13 or AO-40-capable ground station, AMSAT says. Something new to Amateur Radio satellites is a planned low-rate text messaging system similar to cellular telephone SMS. Sanford said the text-messaging capability may prove valuable for providing emergency and disaster communication. It will operate in mode U/V and also will be available to modest ground stations over 75 percent of Eagle's orbit. Eagle will also carry an advanced communications payload (ACP). The ACP will accommodate voice communication using an S2 band (3.4 GHz) uplink and a C band (5.8 GHz) downlink via a single 60 cm dish on the ground. As an alternative -- for stations in those parts of the world where 3.4 GHz is unavailable -- Eagle will provide an additional L band uplink. The ACP also will offer high data rate communication including the possibility of full-motion compressed video in S2/C mode. The same mode also could support an Internet link. Ground-station antennas for Eagle may even pass muster in neighborhoods governed by private deed covenants, conditions and restrictions (CC&Rs), Sanford suggested. During a presentation on the ACP, Matt Ettus, N2MJI, said one of the goals of the package is to open up the satellite to a new base of users, not just restrict it to elite satellite operators and sophisticated ground stations. Embracing SDR technology simplifies signal handling, he explained, because going digital is just a matter of transmitting bits up and down. "The satellite doesn't really care what the bits mean," he said. The satellite "just reflects bits," and most policy-type issues will be handled by ground stations. The satellite's signal will present one wideband downlink containing multiplexed data. "There will be room for many, many carriers in the passband," Ettus predicted. The mix of users would be apportioned among both low and high-rate modes, depending on overall traffic. Plans call for electronically steering the satellite's antennas to mitigate the effects of the spacecraft's spin and maximize the spacecraft's accessibility. In a subsequent forum, AMSAT board member and well-known satellite expert Tom Clark, K3IO (ex-W3IWI) discussed some of the mathematics and physics that would permit steering a 37-element S band antenna array on Eagle. "We would intentionally steer that pattern, so the array is always pointing toward Earth," Clark said, regardless of spin factor. He described a system of interferometers to do the pointing on the basis of "master beacon signals" uplinked from different points on Earth's surface. "It [Eagle] will measure where they are and know where to point the beam," he explained. In a presentation on applying SDR techniques to satellite transponders, Howard Long, G6LVB, described and demonstrated a prototype SDX board. "This is the holy grail of what we've been trying to do," he told his audience. Long showed how his hand-soldered SDX could be configured to accommodate various signal strengths and types within the same passband and even to easily notch interfering signals quickly and flawlessly. Sanford concluded his presentation by saying it's time to take the AMSAT board's concrete decisions and plan, schedule and build Eagle. "We're about to start spending some serous money," he said. During a later question-and-answer session, Sanford stressed that reliability of the ultimate Eagle satellite is a key goal. "I want no single-failure mission kills on this satellite," he said. Project Eagle still needs to raise $33,500 by December. Eagle could launch by 2010. The whole project will cost some $600,000. During the AMSAT-NA annual meeting October 8, President Rick Hambly, W2GPS, expressed his enthusiasm for Project Eagle. "I think it will be the greatest thing we've ever done!" he said. The 2007 AMSAT Symposium and Annual Meeting will take place in Pittsburgh.

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Amateur Radio Newsline Mentions Eagle
by JoAnne Maenpaa 13 Oct '06

13 Oct '06

Bill Pasternak, WA6ITF sends out a pre-release copy of the Amateur Radio Newsline broadcast script to the ANS editors. This week's Newsline will include news about Eagle. Here's a copy for anyone interested ... -- 73 de JoAnne K9JKM k9jkm(a)amsat.org HAM RADIO IN SPACE: THE EAGLE WILL FLY AMSAT's Board of Directors has approved the payloads for the upcoming Eagle ham radio satellite. Bill Pasternak, WA6ITF reports: -- Of primary concern to most radio amateurs world-wide was the decision to include an SSB and C-W transponder transponder with uplink on 70 centimeters and a downlink on 2 meters. What AMSAT calls U-Band and V-Band. This means that Eagle will be usable over 75% of an orbital pass by any AO-13 or AO-40 capable ground station. In other words, Eagle will be backward compatible with most previous ham radio satellites. Other transponders include SSB and C-W with an uplink on L-band and a downlink the 2.4 GHz S1-band and a low rate text message system operating on the UHF and VHF bands. These transponders will be implemented using Software Defined Radio technology. But thats not all.. AMSAT says that Eagle will also carry an advanced communications payload or A-C-P. The A-C-P will allow voice communications uplinking on the S2-band at 3.4 Ghz and downlinking on C-band at 5.8 Ghz. It will do all of this using a single 60cm dish. The satellite antennas will be electrically steered to reduce spin modulation and allow use over 75% of any given orbit. An additional, fix-pointed, uplink will be available at L-band. This L-band uplink will require a separate antenna at the ground station. Also on-board will be C-band equipment for high rate data communications such as streaming video. For the Amateur Radio Newsline, Bill Pasternak, WA6ITF, in Los Angeles. -- The AMSAT board announced its selection following a meeting on October 5th in Sam Francisco. It also said that AMSAT will develop and make available an affordable ground segment for the ACP system. Additional information will be posted at www.amsat.org in the near future. (AMSAT)

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