[amsat-bb] PSLV C-18 Launch successful
Hello All, The PSLV C-18 Mission is a Grand success. All the four satellites were successfully injected into their precise orbits. The Jugna was injected at 05:56 UT and the beacon will turn ON at 06:31 UT. It is expected that the Jugnu at that time should be somewhere over N.W of South America. Any early signal report 0n 437.275 CW from around this part of the World would be greatly appreciated. 73 de Mani, VU2WMY Secretary & Station-In-Charge Upagrah Amateur Radio Club VU2URC ISRO Satellite Centre HAL Airport Road, Bangalore-560 017. Phone:(O)91-80-25082054/2598/2192 Mobile: 91-80-98803 41456 E-mail ID: w...@isac.gov.in vu2wmy_m...@yahoo.com isroh...@yahoo.com -- Confidentiality Notice: This e-mail message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. -- ___ Sent via AMSAT-BB@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
[amsat-bb] SRMSAT
Dear Folks, "SRMSAT" a Nano Satellite from SRM University and "Jugnu" from IIT kanpur, India have been successfully placed in orbit at 11:32 Am IST. I would request the Hams all over the world to track the satellites and send in the beacon data to the following address. kc2...@arrl.net and sanjaynekka...@gmail.com SRMSAT beacon is at 437.425 MHz Jugnu beacon is at 437.275 MHz Thanking you, 73 AB3OE, Sanjay Srikanth Nekkanti. ___ Sent via AMSAT-BB@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
[amsat-bb] Re: ARISsat-1
ARISsat performance. Very poor performance of ARIssat over ZL today (7 passes.). All passes in Low Power Mode except the last which was in Emergency mode. All passes were fully sunlit and had been on for 30 minutes or more before my AOS. A few went to high power mode for a minute or two mid pass but quickly reverted to low power mode. Alan ZL2BX ___ Sent via AMSAT-BB@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
[amsat-bb] Re: KickSat - a personal spacecraft of your own in space
Hi All, In response to Trevor's questions, the current board design is about 3.2 cm x 3.2 cm x 4 mm. At that size, we can fit about 200 in a 1U CubeSat (stacked 3x3x22). We're pretty sure we can thin that down a little more by using thinner PCBs. If we get way more than 200, we can always go to a 2U or 3U CubeSat. What I'd really like to do, however, if we can get enough sponsors, is to make a custom ASIC. If we can make custom silicon, we can get the size and the price way down. This may not be realistic this time around, but it is something I really want to pursue if I can get the money. As far as power, the Sprites are around 10 mW, and yes, they need solar power, so they won't operate through eclipse. They do, however have a bank of capacitors to buffer the power coming out of the solar cells, so tumbling won't be a problem. Thanks, Zac ___ Sent via AMSAT-BB@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
[amsat-bb] Satellite Beacon Tracking Request
Dear friends, As you all might be aware that two cubesats 'Jugnu' and 'SRMSat' using amateur frequencies are to be launched by PSLV C-18 from Satish Dhawan Space Centre [SDSC], Shriharikota, India. The expected launch time is 05:30 UT. In this regard, I'm herewith forwarding the mail from Mr. Shantanu Agarwal, Team Lead for the 'Jugnu', requesting the Global Amateur Radio fraternity to provide the CW Beacon signal Report along with the plain decoded morse message, if possible. Any help in this regard would be greatly appreciated, as this would be very helpful to evaluate various ob-board system performance. 'Jugnu' beacon is at 437.275 MHz, OOK. The reports can be sent to the following mail ID.s w...@isac.gov.in[1] shan...@iitk.ac.in[2] The predicted TLE's: JNU 1 9U 11072A 11285.2472 .1785 0-0 96625-3 0 1235 2 9 20.0506 66.7109 0018405 5.1080 190.7439 14.1133892219 SRM 1 8U 11072A 11278.34967500 .1077 0-0 60876-3 0 1233 2 8 20.0603 97.4017 0010015 338.6461 208.4324 14.0919996814 Thanks in advance and looking forward to your valuable reports. 73 de Mani, VU2WMY Secretary & Station-In-Charge Upagrah Amateur Radio Club VU2URC ISRO Satellite Centre HAL Airport Road, Bangalore-560 017. Phone:(O)91-80-25082054/2598/2192 Mobile: 91-80-98803 41456 E-mail ID: w...@isac.gov.in[3] vu2wmy_m...@yahoo.com[4] isroh...@yahoo.com[5] - Forwarded message from shan...@iitk.ac.in[6] - Date: Tue, 11 Oct 2011 20:06:56 +0530 From: Shantanu Subject: Satellite Beacon Tracking Request To: w...@isac.gov.in[8] Dear Sir, We will be thankful if you can track our satellite beacon after launch. You are requested to kindly post our satellite details on various HAM groups to track our satellite beacon after launch. Our satellite beacon is at 437.275 MHz, OOK. Thanks. Shantanu Agarwal - End forwarded message - Links: -- [1] mailto:wmy%40isac.gov.in [2] mailto:shantag%40iitk.ac.in [3] mailto:wmy%40isac.gov.in [4] mailto:vu2wmy_mani%40yahoo.com [5] mailto:isrohams%40yahoo.com [6] mailto:shantag%40iitk.ac.in [7] mailto:shantag%40iitk.ac.in [8] mailto:wmy%40isac.gov.in -- Confidentiality Notice: This e-mail message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. -- ___ Sent via AMSAT-BB@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
[amsat-bb] Re: Geostationary Satellites
> Question, what is the closest spacing for geo > satellites to share the same slot? > Is this theoretically practical and or possible? I think someone already said that there are no such thing as physical slots. Slots are FREQUENCY based. Meaning their separation only has to be as great as the beamwidth of the grouind based antennas that will use them IF they are on he SAME frequency. So "C" band satellites were originally at 4 degree separation (10 foot dishes) then went to 2 degree separation by making evrey other TV channel be oppositely polarized. Such spacing only applies to large constellatiosn of birds on the SAME identical frequency plans. (such as consumer TV downlinks). If we had ground receive antennas that had beamwidths the width of the moon, then we couild have nearly 720 slots (each 0.5 deg wide). If a GEO constellation used laser communications links, with user ground stations using OPTICAL telescopes, there could be a million slots because the telescopes could resolve them down to .0003 degrees? Oh, for HAMS with an OSCAR array and beamwidths of say 30 degrees, then there could be 12 slots. Bob, WB4APR ___ Sent via AMSAT-BB@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
[amsat-bb] Endeavour's Pink Slip Transferred
Michael Curie Headquarters, Washington 202-358-1100 michael.cu...@nasa.gov RELEASE: 11-343 NASA TRANSFERS ENDEAVOUR TITLE TO CALIFORNIA SCIENCE CENTER WASHINGTON -- NASA transferred title and ownership of space shuttle Endeavour to the California Science Center (CSC) during a ceremony Tuesday at the center in Los Angeles. The transfer is the first step toward CSC receiving Endeavour in the latter half of 2012. "NASA is pleased to share this wonderful orbiter with the California Science Center to help inspire a new generation of explorers," NASA Administrator Charles Bolden said. "The next chapter in space exploration begins now, and we're standing on the shoulders of the men and women of the shuttle program to reach farther into the solar system." Bolden announced April 12 that CSC was one of four institutions nationwide to receive a shuttle. After display preparation and post-mission work are complete, NASA will deliver Endeavour on the 747 shuttle carrier aircraft to Los Angeles International Airport. >From there, the shuttle will be driven through the streets of Los Angeles to its destination at the Science Center in Exposition Park. "Endeavour now will begin its new mission to stimulate an interest in science and engineering in future generations at the science center," California Science Center President Jeffrey Rudolph said. For information about where all the retired space shuttles will be displayed, visit: http://www.nasa.gov/mission_pages/transition/placement/index.html -end- Clint Bradford clintbradf...@mac.com ___ Sent via AMSAT-BB@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
[amsat-bb] KiwiSAT Camera
Hi Guys, Been asked by the student that is running some tests on the very simple camera that we are installing on KiwiSAT, what the cost would be of a commercial satellite surveillance camera. He has not found any prices despite web searching - and I haven't done much better! He wants to contrast the cost of our simple unit to a proper industrial one in a .ppt presentation on his findings. Can someone out there in the business give us an idea of the range from the simplest to the most sophisticated? (Has to be mega bucks!) ( Cost of ours ?- about $100! But flown successfully and reliably (for our purpose) on several Cubesats!!!) Thanks Fred Kennedy ZL1BYP KiwiSAT Project Leader ___ Sent via AMSAT-BB@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
[amsat-bb] India PSLV C-18 Launch with Jugnu and SRMSAT Webcast
Hello Everyone, Here is one news item that will happen before the weekend ANS bulletins are sent out: The PSLV C-18 launch from India's Satish Dhawan Space Centre [SDSC], in Shriharikota, India will be webcast live at http://www.isro.org/. The expected launch time is 05:30 UTC October 12. The Jugnu team is requesting CW beacon signal reports along with the plain decoded morse message be sent to the following mail IDs: w...@isac.gov.in shan...@iitk.ac.in The SRMSat reports can be sent to: sanjaynekka...@gmail.com Jugnu Frequency: CW Beacon - 437.275 MHz (17dbm) SRMSAT Frequency: CW Beacon - 437.425 MHz (10dbm) Preliminary TLEs from ISTRAC (ISRO Telemetry, Tracking and Command Network): SRM 1 9U 11072A 11278.34967500 .1077 0-0 60876-3 0 1233 2 9 20.0603 97.4017 0010015 338.6461 208.4324 14.09199968 14 http://www.amsat.org/amsat/archive/amsat-bb/48hour/msg90110.html (amsat-bb) More information and a countdown clock can be found on-line at: http://srmsat.in/ -- 73 de JoAnne K9JKM k9...@amsat.org Editor, AMSAT News Service ___ Sent via AMSAT-BB@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
[amsat-bb] Re: Geostationary Satellites
What you're describing is the AMSAT Phase 3 paradigm which IMHO is still the most viable way to go. I would never say never, but we (AMSAT) haven't had great success with propulsion systems in our amateur satellites. That is why I'd like to have more experience with successful propulsion events in Molniya-like orbits before I'd recommend attempting maintaining a GEO orbit. 73, Ken N2WWD Sent from my iPad On Oct 11, 2011, at 4:41 PM, Joe wrote: > How hard (Energy) budget is it to have that giant elliptical orbit, I can't > remember what bird had it, but it was an orbit named like moylina or > something like that where the perigee was very low but the apogee was like > WAY out there giving passes that were extremely long. > > Joe WB9SBD > > The Original Rolling Ball Clock > Idle Tyme > Idle-Tyme.com > http://www.idle-tyme.com > > On 10/11/2011 3:27 PM, Gordon JC Pearce wrote: >> On Tue, 11 Oct 2011 15:08:01 -0400 >> Ken Ernandes wrote: >> >> >> >>> I hope this is somehow helpful in understanding what AMSAT would really be >>> up against if it wanted to have an independent GEO satellite or consider a >>> sub-GEO drifting orbit. >> Thank you Ken, for the rocket scientist's take on it ;-) >> >> It's refreshing to hear someone who actually has sat down and done the maths >> comment on how easy or hard it would be to put a satellite into a high orbit. >> > ___ > Sent via AMSAT-BB@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@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
[amsat-bb] Re: Geostationary Satellites
--- On Tue, 11/10/11, Joe wrote: > How hard (Energy) budget is it to have that giant elliptical orbit, > I can't remember what bird had it, but it was an orbit named like > moylina or something like that where the perigee was very low > but the apogee was like WAY out there giving passes that were > extremely long. It's a great orbit, AO-40 was aiming for it. Bottom line is cost - $10-15 million for launch to Geo transfer orbit and then costs of incorporating and controlling a motor on the sat to get it to Moylina. You should be able to build the sat for a million or so - it's the launch costs that are the killer. 73 Trevor M5AKA ___ Sent via AMSAT-BB@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
[amsat-bb] Re: SatPc32 kepler Data
I'm guessing you're running XP on that computer? If so, the kepler folder is now (v12.8) located at C:\Documents and Settings\Owner\Application Data\SatPC32\Kepler where "Owner" is the profile name you sign on with. George, KA3HSW - Original Message > From: Howard Kowall > To: amsat-bb@amsat.org > Sent: Tue, October 11, 2011 2:49:10 PM > Subject: [amsat-bb] SatPc32 kepler Data > > Hello all > I have an older laptop that has no internet connection,I run Satpc32 on my >main computer that has internet connection and I am able to update the kepler >data.I want to use the kepler data from my main computer,and copy it to my >laptop via USB flash drive.I cant seem to find the kepler folder in the >SatPc32 folder.Has anyone one shared the kepler data. > Thanks to all who read and reply in advance > Howard > VE4ISP ___ Sent via AMSAT-BB@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
[amsat-bb] Re: SatPc32 kepler Data
Howard, This depends on your OS and the version of SatPC32. On more current versions of both software and OS, the folders are HIDDEN by default, so you to make sure you have can see all files (it's Windows Folders option). It's a tad annoying...so get those files unhidden. On a Windows7 system using SatPC32 12.8a, the files are here (where username is the name of the user account in Win7). C:\Users\username\AppData\Roaming\SatPC32\Kepler (In the SatPC32 window where you select the keps files---you can see the path at the bottom of the window...) Hope that helps :) 73, Mark N8MH At 02:49 PM 10/11/2011 -0500, Howard Kowall wrote: >Hello all >I have an older laptop that has no internet connection,I run Satpc32 on my >main computer that has internet connection and I am able to update the kepler >data.I want to use the kepler data from my main computer,and copy it to my >laptop via USB flash drive.I cant seem to find the kepler folder in the >SatPc32 folder.Has anyone one shared the kepler data. >Thanks to all who read and reply in advance >Howard >VE4ISP >___ >Sent via AMSAT-BB@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@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
[amsat-bb] Re: Geostationary Satellites
How hard (Energy) budget is it to have that giant elliptical orbit, I can't remember what bird had it, but it was an orbit named like moylina or something like that where the perigee was very low but the apogee was like WAY out there giving passes that were extremely long. Joe WB9SBD The Original Rolling Ball Clock Idle Tyme Idle-Tyme.com http://www.idle-tyme.com On 10/11/2011 3:27 PM, Gordon JC Pearce wrote: On Tue, 11 Oct 2011 15:08:01 -0400 Ken Ernandes wrote: I hope this is somehow helpful in understanding what AMSAT would really be up against if it wanted to have an independent GEO satellite or consider a sub-GEO drifting orbit. Thank you Ken, for the rocket scientist's take on it ;-) It's refreshing to hear someone who actually has sat down and done the maths comment on how easy or hard it would be to put a satellite into a high orbit. ___ Sent via AMSAT-BB@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
[amsat-bb] Re: SatPc32 kepler Data
Howard, I was curious since I seem to remember these as you do. I looked at the download screen and it points to: C:\users\name of user\appdata\roaming\satpc32\kepler\ My user name happens to be "DEE" Hope you find it. 73, Dee, NB2F -Original Message- From: amsat-bb-boun...@amsat.org [mailto:amsat-bb-boun...@amsat.org] On Behalf Of Howard Kowall Sent: Tuesday, October 11, 2011 3:49 PM To: amsat-bb@amsat.org Subject: [amsat-bb] SatPc32 kepler Data Hello all I have an older laptop that has no internet connection,I run Satpc32 on my main computer that has internet connection and I am able to update the kepler data.I want to use the kepler data from my main computer,and copy it to my laptop via USB flash drive.I cant seem to find the kepler folder in the SatPc32 folder.Has anyone one shared the kepler data. Thanks to all who read and reply in advance Howard VE4ISP ___ Sent via AMSAT-BB@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@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
[amsat-bb] Re: Geostationary Satellites-HEO MEO
All, As most of you know me, I am one of the voices in the crowd within satellite circles and have been accused of having my own agenda. I am a fixture at many hamfests here in the New Jersey Area and wherever I can present to the Amateur community the aspects of satellite activity and promote AMSAT's proliferation. I give many talks and dog and pony shows to various clubs. My motto is "I work for donations!" I am glad this thread was ongoing since I come across this type of thinking all the time. It's a good discussion since AMSAT membership is declining and Satellite enthusiasm is dwindling, so I read. While this area of insuring plans for HEO and MEO birds is one of my pet projects, AMSAT itself has re-addressed itself to LEO activities because of financial reaches that present launches are out of the normal (?) abilities of AMSAT to obtain. My many unscientific polls as to why hams are not rejoining AMSAT nor assisting future funding shows that they think we have to put up HEO or MEO birds to attract them back into the fold. Of course this doesn't make sense and it doesn't add to our present coffers to even think about these type of birds. Yes, it costs money to do these things. In the past, there were negotiations behind the scenes with a GEO-Sync satellite company to add our payload to one of these birds. Company was sold, contacts were lost and so went that avenue. As with an AO-40 type satellite, we had numerous items made by our supporting volunteers and many, many, many volunteer hours to see that satellite came to fruition. Volunteers even gave up precious vacation time to work on this project. A minimal cost launch by Arianne certainly provided a great opportunity. Some of our people went by the wayside since then and we lost engineering staff to fall back on. As Dan, N8FGV, points out to us all is that our dreams are still there. We need to reactivate those spirits as he indicates. One person stated, "I am willing to ante up $4000-I need to convince 4,999 of my friends to do the same." We are all Amateurs in this satellite area and as pioneers in Ham Radio, we must reinvent ourselves to continue to be prominent in building sats with real actual launches rooted out where we can. We have dedicated people now in active building projects for slots available for launch. My hat is off to them and I will always support their efforts. Having functioning packages on the ready is a big plus- Look at ARISsat-1 and that was a super job by "OUR" staff to step up and act before the deadline. (We don't need no stinkin' UHF antenna!) (OOPS?) Dan provides us with answers to all these questions of why and why not. Read his input as well and I think this thread needs the answer of how much is the Amateur community willing to contribute to keep these higher orbiting satellite ideas alive. Anyone have a "RICH" uncle to donate something to this superfund? I think that we need a spark - incentive - or a benefactor to step up to get us on the launch pad at the right spot. Lottery tickets seem to be the American dream (HI, HI). Please feel free to "thank" our many sincere volunteers that keep publications coming, transponders appearing, protecting frequency allocations, monitoring rule proposals, Symposiums happening and informational updates accurate. 73, Dee, NB2F NJ AMSAT Coordinator -Original Message- From: amsat-bb-boun...@amsat.org [mailto:amsat-bb-boun...@amsat.org] On Behalf Of Daniel Schultz Sent: Tuesday, October 11, 2011 2:03 AM To: amsat-bb@amsat.org Subject: [amsat-bb] Re: Geostationary Satellites It is true that a Geo bird would only cover 1/3 of the Earth, but it would ALWAYS be there, with no need for antenna rotors or keps or a computer for tracking. It would be like picking up a telephone. It would be wonderful for emergency service in a disaster area. It could provide high speed digital communications on the amateur microwave bands in places where the internet is not available. Geosynchronous orbit slots are allocated by transponder frequency. On the amateur radio bands we are free to locate a satellite anywhere we can get to because we don't share our frequencies with commercial transponders. The reason we don't have any high altitude satellites is all about the money. We amateurs created the small satellite business. Back in the old days the big boys laughed at our cute little toy satellites, but they did allow us to bolt them to a launch vehicle for free or for very low cost. The experts were certain that our homebrew satellites wouldn't last a week without expensive mil-spec electronic components. We amateurs proved that small satellites were useful and thus created a market that we are now priced out of. The launches that used to be free can now be sold to paying customers for millions of dollars. Many of the companies in the small satellite business were founded by Amsat alumni. We amateurs are a non-commercial service, by law, with no product or serv
[amsat-bb] Re: Geostationary Satellites
On Tue, 11 Oct 2011 15:08:01 -0400 Ken Ernandes wrote: > I hope this is somehow helpful in understanding what AMSAT would really be up > against if it wanted to have an independent GEO satellite or consider a > sub-GEO drifting orbit. Thank you Ken, for the rocket scientist's take on it ;-) It's refreshing to hear someone who actually has sat down and done the maths comment on how easy or hard it would be to put a satellite into a high orbit. -- Gordon JC Pearce MM0YEQ ___ Sent via AMSAT-BB@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
[amsat-bb] SatPc32 kepler Data
Hello all I have an older laptop that has no internet connection,I run Satpc32 on my main computer that has internet connection and I am able to update the kepler data.I want to use the kepler data from my main computer,and copy it to my laptop via USB flash drive.I cant seem to find the kepler folder in the SatPc32 folder.Has anyone one shared the kepler data. Thanks to all who read and reply in advance Howard VE4ISP ___ Sent via AMSAT-BB@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
[amsat-bb] Re: Geostationary Satellites
Question, what is the closest spacing for geo satellites to share the same slot? Is this theoretically practical and or possible? Dave Marthouse N2AAM dmartho...@gmail.com ___ Sent via AMSAT-BB@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
[amsat-bb] Re: Geostationary Satellites
How about a high altitude drifter above the geo belt? In fact wasn't that talked about by a few amsat people in the early 80's. I seem to remember hearing it discussed by the late Rip WA2LQQ on the 75 meter Amsat net back in the day. Dave Marthouse N2AAM dmartho...@gmail.com ___ Sent via AMSAT-BB@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
[amsat-bb] Re: Geostationary Satellites
Paul - Your final suggestion is something that is workable. Placing a satellite say 200 km below GEO would result in the satellite drifting about 10 minutes per day or about 2.5 degrees per day. This would result in a cycle that repeats about every 144 days (or about 2.5 times per year), relative to a ground-based observer. I'd need to see if 200 km is safe or if that might need to be increased. An increase would correspondingly increase the drift rate. As I said, that could be workable for an amateur satellite, but before the calls go out for this being AMSAT's next project we need to understand what we'd need to do, and what you'd actually be getting. To get to such an orbit from a GTO would require about 950 m/sec of delta-V to raise perigee up and establish a nearly circular orbit, slightly below GEO. If the propulsion system had 90% efficiency and we had a bi-propellant system with a 285 sec specific impulse (Isp), the propellant mass would be about 31.5% of the total spacecraft launch mass. That is if we are willing to also accept the inclination that the launch booster dropped us off in. I suspect we would accept the booster's inclination for reasons that we'll see. Now I'd like to give a quick outline of the disturbing forces at GEO, since out spacecraft would experience similar effects. I'll start with what's commonly called Earth triaxiality. Many of us know the Earth bulges at the equator. So the first of the three axes is the Earth's rotational axis. But the equator is not perfectly circular. The equator itself has its own ellipsoidal shape, leading to two additional gravitational axes in the equatorial plane. The result is that satellites on the GEO belt will tend to drift east or west (depending on location). There are four equilibrium points, two of which are stable (about 75-deg E and 105-deg E) and two of which are not stable (about 12-deg W and 162-deg E). The unstable points are the demarcations in which you will drift either east or west depending on which side of the that point you're located. The stable points are the graveyards where all the dead satellites that haven't been boosted out of the GEO belt will collect. The drift rate varies and is lowest near the equilibrium points and greatest at the mid-points between the equilibrium p! oints. Given the case of a sub-GEO orbit, the drift due to triaxiality is of little consequence since the drift due to thee altitude difference is far greater and triaxiality would be reduced to a secondary effect. It was provided here for understanding of what we would need to deal with if we wanted to hold at GEO and not collide with out neighbors. A very significant effect results from the gravitational pulls on the satellite by the Sun and Moon. (To be completely accurate, this is the difference between the pulls on the satellite and the Earth by these bodies.) This causes the inclination to cycle between 0 and approximately 15-deg over a period of about 53 years. Anybody familiar knows that inclination change maneuvers require a lot of propellant. Thus, I believe we would accept this slowly-changing inclination and realize that our antennas would need to adjust slowly over the course of the day in what is typically a figure-8 pattern. Depending on your latitude, there may be periods when the satellite dips below your horizon. A final effect to be considered is Solar Radiation Pressure. The impact pressure from the Sun's photons impart momentum on the spacecraft, which in turn causes a slight change in velocity. The main effect is a change to the orbital eccentricity. For GEO satellites, eccentricity is manifest mainly by an east/west oscillation over the course of a day. The larger the eccentricity, the greater the amplitude of the oscillation. At first blush this may seem like an insignificant effect for out sub-GEO for the same reasons as we became unconcerned about triaxiality effects. But eccentricity also equates to changes in altitude - precisely what we were using as our guard against colliding with satellites in the GEO belt. So the long-term effects would need to be considered when choosing what we consider to be a safe separation from thee GEO belt. I hope this is somehow helpful in understanding what AMSAT would really be up against if it wanted to have an independent GEO satellite or consider a sub-GEO drifting orbit. 73, Ken Ernandes N2WWD Sent from my iPad On Oct 11, 2011, at 12:05 PM, Paul Williamson wrote: > On Oct 11, 2011, at 3:31 AM, Ken Ernandes wrote: >> For those believing in the large space, small satellite theory, the risk of >> collision is more real than one might think. > > It must be, since I would think the risk of collision is so tiny as to be > effectively negligible. If we position our satellite halfway between two of > those commercial "slots", we have a huge buffer on either side. Now I realize > that just mea
[amsat-bb] Re: KickSat - a personal spacecraft of your own in space
Hi Zac, I wish you well with the project it's a great idea. I'd like to clarify the number of sprites that will be carried on the first 1U CubeSat. The website says: "KickSat is a CubeSat - a standardized small satellite that we can easily launch. It is designed to carry hundreds or even thousands of Sprites into space and deploy them in low Earth orbit." Now looking at the picture showing the size of the boards for the initial deployment you aren't going to get 100's into a 1U CubeSat. How many will be deployed ? I gather the Sprites have a very short lifetime, just days rather than months. Can you clarify the power level that will be used. Is it 10 milliwatts or lower ? and is that power only available when the Sprite's solar panels are illuminated ? 73 Trevor M5AKA ___ Sent via AMSAT-BB@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
[amsat-bb] Re: geostationary satellite:thinking outside the box
I wonder if we could build a LEO uplinking to and downlinkingf rom a geosationary satellite on its spare transponder capacity? Initially by AX25 packet from ground to the LEO sat on our frequencies, then by license up to the geo which would see the leo longer than a ground station would? just my 1 penny worth... 73 de andy g0sfj ___ Sent via AMSAT-BB@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
[amsat-bb] Re: Geostationary Satellite
I agree that the "best" hope for a GEO payload is a hosted one on a commercial sat, but the odds of it happening are pretty thin. The biggest obstacle to this is not station keeping fuel however. There are few satellites that simply run out of station keeping fuel with all their transponders working. What ages a satellite is that the transponders start failing, the solar power system starts degrading...etc. It simply IS NOT that they come up to the disposal fuel and thats it. The biggest obstacle is integration of an amateur payload built by amateurs into something that has to work or there is a lot of money lost and there is no insurance recovery if something like an amateur payload caused the failure...or even some sort of problem with the primary payload. If AMSAT or anyone else could go for hosted payloads the best possible approach to that is some of the new intermediate altitude comm systems that are out there now looking for hosted payloads... Robert G. Oler WB5MZO Life member AMSAT ARRL NARS > From: howied...@hotmail.com > To: amsat-bb@amsat.org > Date: Tue, 11 Oct 2011 10:01:20 -0400 > Subject: [amsat-bb] Re: Geostationary Satellite > > > I agree with much of what Dan, N8GFV, says. Our best hope of a high altitude > satellite is probably a hosted payload on a GEO sat. To make that viable we > need to consider the entire mission. GEO satellite operators are a for-profit > business and every aspect of a commercial satellite has a dollar value. The > major items are spectrum, power and fuel. Since hams bring their own > spectrum, that is a no cost item for us. If we need to use satellite power > then we would need to pay the market rate for the percentage of the total > satellite resource used for the design lifetime of the satellite, typically > 15 years. If the payload can be disabled by the operator we may be able to > negotiate a pay as you go plan so that we don't have to pre-pay 15 years > worth of power. Developing very power efficient transponder systems will > reduce our costs. Trading bandwidth for power by using digital encoding, > strong FEC, regenerative transponders with DSP signal enhancement will all > aid in the reduct! io! > n of the power required to close a link. > The other big cost factor is fuel. As previously stated here, station keeping > is a critical element in GEO satellites and with the advances of component > technology, a satellites lifetime in orbit is determined primarily by the > amount of station keeping fuel it can carry. The more fuel, the longer the > satellite life, the more time the operator can use to recover their > investment and make money. Every ounce added to the satellite affects the > cost of the launch and possibly the amount of fuel that can be carried on > board. Whether this is the case or not, the added satellite weight WILL add > to the launch cost that we would have to pay. > The good news is that the AMSAT community and the satellite operators have > common interests in making satellites less expensive and more efficient. By > building on the technology pioneered in ARISSAT-1 we MAY be able to get some > cooperation from a commercial operator to deploy a technology demonstration > package as a hosted payload. This might be more probable than one thinks. > Satellite operators are EXTREMELY conservative and don't deploy new > technology until it is thoroughly proven. The commercial satellite market is > running out of real estate. Many of the big operators are at over 80% > capacity. Since they are for-profit organizations, they are running out of > product quickly and will not be able to grow their business. All the major > operators are investing large amounts of money to promote a hosted payload > business where government and scientific users can bring their own bandwidth > to a transponder or payload on the operators platform. A low cost, high > performance, innovat! iv! > e payload COULD be a great advertising tool for a commercial operator. The > operator would get the payload for zero cost and could also get part of the > launch cost subsidized by AMSAT in return for a real world, open source > demonstration tool. > If we build this payload along the lines of Tom Clark's C-C rider concept > with a 5 GHz up/ 3 GHz. down transponder we can probably even use the > satellites low gain telemetry antenna, further reducing payload costs. > Sorry for the lengthy post but I have been thinking about this for a while > and this seemed like a good opportunity to finally put it in writing. > HowieAB2S > ___ > Sent via AMSAT-BB@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 __
[amsat-bb] % in EM55
The 5 in em55 award info can be seen on QRZ lookup WA4NVM or WA4HFN . Skeds are ok too. Several donations to AMSAT have been made from this award Thank you ___ Sent via AMSAT-BB@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
[amsat-bb] Re: Geostationary Satellites
>> the risk of collision is more real than one might think. > I would think the risk of collision is so tiny > as to be effectively negligible. I think it is, but when "negligible" incurs about a BILLION$$$ worth of loss, it magnifies the risk. > If we position our satellite halfway between two... "slots" I think that is the problem. One has to stay there. GEO orbits are impacted by the sun, moon and tides and solar wind. All GEO orbits drift*. Hence 90% of the mass of these GEO birds are fuel for station keeping. And that is where the risk comes from. As soon as a spacecraft loses fuel, or command/control, or any other problem that causes it to no longer keep its station, it becomes a drifting hazard, moving literally FOREVER along this extremely narrow orbit, the same orbit that all of these other satellites are in! It becomes a real hazard to them all. That is why all nations now subscribe to the requirement that all GEO spacecraft must have 10% reserve fuel to propel an aging satellite out to the graveyard orbit. And this must be done before there is loss of command/control. > Is there no clever trick of orbit design > that can be used to avoid collision? Not and be geostationary. I think long term drift is the final state of any GEO orbit. Though there are , I think, *two spots on the entire GEO orcit which are stable.. but guess what. NO ONE WANTS them, because that is where all the junk collects and that is where the chances of a collision with all that junk is highest. > We can even tolerate some long-term motion... > Perhaps these extra freedoms would make it possible > to design an orbit that's close enough to geosynchronous > for our purposes, but far enough from the commercial orbits to be safe? I'd guess that being in an orbit closer to earth would be best so that with time we get further from the GEO arc. But closer in, moves faster and so all we have to do is chose the DRIFT rate. Let it drift a full cycle once a year, and the result is that any given country only sees it for 4 months a year. No matter where we put it, it will be out of view to any one station 2/3rds of the time. But now that it is in its own special orbit, there wont be any cheap rides to get there... Our best bet is to piggy back on someone else's bird. Oh, and it takes almost 10,000 times more power to hit a GEO bird at 22,500 miles away compared to hitting a LEO bird directly overhead (225 miles). Just my 2 cents Bob, Wb4APR ___ Sent via AMSAT-BB@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
[amsat-bb] WD9EWK @ Tucson AZ hamfest and post-hamfest activity, 22 October
Hi! The hamfest season out here in Arizona is about to start. I will be at the Old Pueblo Radio Club's annual hamfest in Tucson AZ a week from Saturday, on 22 October 2011. This is a week later than usual, since this hamfest has normally taken place the same weekend as the Scouting Jamboree on the Air event. The hamfest will be at the usual location in Tucson, at the Kino Sports Complex along the north side of Ajo Way at Forgeus Avenue, east of the I-10 freeway and the baseball stadium (grid DM42me). The hamfest officially runs from 7am-noon (1400-1900 UTC), although people start showing up before sunrise and many leave before noon. During the hamfest, WD9EWK will be on whatever FM and SSB satellites are available doing on-air demonstrations. On the SSB birds, I try to park about 5-10 kHz above the center of the transponders, depending on other activity and QRM/QRN. Please feel free to call WD9EWK during those demonstrations and say "hello" to the crowds. After the hamfest, I plan on driving either to the DM51bx/DM52ba or DM52ax/DM53aa grid boundaries in southeastern Arizona to work some passes on my way home. I have operated from both of these grid boundaries earlier this year - DM51bx/DM52ba in early May, and DM52ax/DM53aa in late March - and try to visit these locations when I attend hamfests in southern Arizona. If you have a preference on which boundary I should try to work from after the hamfest, please e-mail me directly. I can't guarantee I will go to the spot you would prefer, but it helps to know what people are interested in hearing on the birds. As with the hamfest demonstrations, I am prepared to work both FM and SSB from wherever I go out there. As with my other trips away from the Phoenix area, there is no need to send me a QSL request to get a WD9EWK QSL card for a hamfest QSO or a QSO from one of those grid boundaries. Just e-mail me the QSO details - if you're in the log, you'll get a card. QSOs will also be uploaded to the Logbook of the World system as WD9EWK, including the grid(s) and county for each QSO. 73! Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/ ___ Sent via AMSAT-BB@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
[amsat-bb] Re: KickSat - a personal spacecraft of your own in space
Hello All, Sorry for taking so long to respond here on the AMSAT-BB - I know I've spoken with some of you separately by email through kickstarter, but I wanted to make sure I responded to everyone's concerns. In response to Andreas' comments about wanting to use his own hardware to listen to the Sprites, this is exactly the sort of thing I want to encourage, and why I initially posted here. I posted a brief "Amateur Radio Information" item in the FAQ on kickstarter with some of this information, but I'll try to cover everything here. The Sprites will all be on the same frequency in the 70 cm band, and each will use a unique PRN spreading code so they can be identified. The hardware you'll need to receive these signals will be a yagi, rotator, LNA, and software defined radio (SDR) interface. We've been using a USRP box from Ettus Research along with GNU Radio, but the USRP is pretty expensive, so we're trying to make everything work with the FUNCube dongle (http://www.funcubedongle.com/). To work with the FUNCube, we have to make sure the signal bandwidth is < 80 kHz (it's currently around 100 kHz). I'll be posting all the details of our setup as we refine it, as well as all the code for the SDR. Even if you don't sponsor a Sprite, it would be great to have more people on the ground listening in. Everything we're doing will be documented, open-sourced, and freely available online. We will most definitely abide by all regulations and apply for frequency coordination with the IARU. We haven't taken that step yet because we have to actually be slotted for a specific launch first. This is also why we don't know our exact frequency yet. Please let me know if you have any additional questions. Thanks, Zac ___ Sent via AMSAT-BB@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
[amsat-bb] Re: Am-Comm Clear Speech Base DSP Filter For Sale
The unit has been taken. Thanks to those who inquired. 73s, Alan WA4SCA -Original Message- From: amsat-bb-boun...@amsat.org [mailto:amsat-bb-boun...@amsat.org] On Behalf Of Alan P. Biddle Sent: Monday, October 10, 2011 3:33 PM To: AMSAT-BB Subject: [amsat-bb] Am-Comm Clear Speech Base DSP Filter For Sale I am doing some shack cleaning. This unit was originally sold by Am-Comm. Since then, the basic electronics have been repackaged, sometimes combined with a speaker, and sold by various companies. My experience is that most of the time it is amazing, though rarely it does very little. The exact improvement depends on the signal, type of noise, levels, etc. It made the difference on AO-40 around apogee. http://www.eham.net/reviews/detail/1041 Currently West Mountain Radio is selling a similar unit, with an adjustable threshold added: http://www.westmountainradio.com/product_info.php?products_id=clr_dsp The unit is perfect mechanically and electrically. $80 including shipping in North America. Please contact me off list. Alan WA4SCA ___ Sent via AMSAT-BB@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@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
[amsat-bb] Fwd: Satellite Beacon Tracking Request
Dear friends, As you all might be aware that two cubesats 'Jugnu' and 'SRMSat' using amateur frequencies are to be launched by PSLV C-18 from Satish Dhawan Space Centre [SDSC], Shriharikota, India. The expected launch time is 05:30 UT. In this regard, I'm herewith forwarding the mail from Mr. Shantanu Agarwal, Team Lead for the 'Jugnu', requesting the Global Amateur Radio fraternity to provide the CW Beacon signal Report along with the plain decoded morse message, if possible. Any help in this regard would be greatly appreciated, as this would be very helpful to evaluate various ob-board system performance. 'Jugnu' beacon is at 437.275 MHz, OOK. The reports can be sent to the following mail ID.s w...@isac.gov.in shan...@iitk.ac.in The predicted TLE's: JNU 1 9U 11072A 11285.2472 .1785 0-0 96625-3 0 1235 2 9 20.0506 66.7109 0018405 5.1080 190.7439 14.1133892219 SRM 1 8U 11072A 11278.34967500 .1077 0-0 60876-3 0 1233 2 8 20.0603 97.4017 0010015 338.6461 208.4324 14.0919996814 Thanks in advance and looking forward to your valuable reports. 73 de Mani, VU2WMY Secretary & Station-In-Charge Upagrah Amateur Radio Club VU2URC ISRO Satellite Centre HAL Airport Road, Bangalore-560 017. Phone:(O)91-80-25082054/2598/2192 Mobile: 91-80-98803 41456 E-mail ID: w...@isac.gov.in vu2wmy_m...@yahoo.com isroh...@yahoo.com - Forwarded message from shan...@iitk.ac.in - Date: Tue, 11 Oct 2011 20:06:56 +0530 From: Shantanu Subject: Satellite Beacon Tracking Request To: w...@isac.gov.in Dear Sir, We will be thankful if you can track our satellite beacon after launch. You are requested to kindly post our satellite details on various HAM groups to track our satellite beacon after launch. Our satellite beacon is at 437.275 MHz, OOK. Thanks. Shantanu Agarwal - End forwarded message - -- Confidentiality Notice: This e-mail message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. -- ___ Sent via AMSAT-BB@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
[amsat-bb] Re: Geostationary Satellites
On Oct 11, 2011, at 3:31 AM, Ken Ernandes wrote: > For those believing in the large space, small satellite theory, the risk of > collision is more real than one might think. It must be, since I would think the risk of collision is so tiny as to be effectively negligible. If we position our satellite halfway between two of those commercial "slots", we have a huge buffer on either side. Now I realize that just measuring distances doesn't capture the whole story, and that orbital dynamics can be non-intuitive, but it boggles the mind that objects spaced that far apart can't be kept from colliding without extraordinary measures. I would say that I'd like to see the analysis to back up the worry, but I doubt I'd understand it. You would, though, so I can only ask whether you have seen the actual analysis and found it compelling. Is there no clever trick of orbit design that can be used to avoid collision? We can afford bigger position errors than the commercial guys can, because we have smaller ground station antennas and no problem with interference crowding. We can even tolerate some long-term motion, since we can certainly accept an occasional adjustment to each ground station. Perhaps these extra freedoms would make it possible to design an orbit that's close enough to geosynchronous for our purposes, but far enough from the commercial orbits to be safe? 73 -Paul kb...@amsat.org ___ Sent via AMSAT-BB@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
[amsat-bb] Re: Geostationary Satellite
Op 11-10-2011 16:23, Joe schreef: Too bad we can't get one of the TV sat people to allow us to have one of their channels. It would be wide enough to hold hundreds of QSO's at the same time for sure. And I bet they have at least one that isn't doing anything at all. But of course thats not a ham band either bummer! Joe WB9SBD The Original Rolling Ball Clock Idle Tyme Idle-Tyme.com http://www.idle-tyme.com That has been done in the 90's upto december 2001, the dutch ATV relay PI6ALK had a digital stream on Astra 1 satelite using a demonstation transponder. In the end it was not the transponder that caused the end of this experiment but the cost of running the uplink station. 73 Andre PE1RDW ___ Sent via AMSAT-BB@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
[amsat-bb] 2011 AMSAT Space Symposium Hotel Reservations
People - I have contacted the Wyndham hotel in San Jose CA and they have agreed to move the cutoff date for room reservations to *October 24th*. The phone number is 408-453-6200 and the reservation block code is AMSAT. The Symposium is November 4th - 6th with an optional tour on Sunday. For more information, go to the AMSAT website. Don't forget to register for the meeting and the banquet at the AMSAT store found on the website. -- 73- Martha ___ Sent via AMSAT-BB@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
[amsat-bb] Re: Geostationary Satellite
I ask this in all seriousness though. Is a giant repeater in the sky with no need to handle Doppler shift really something that would be used? That would take some of the magic out of it. Having to follow a schedule and have the computer and radio synced to correct for the shift is part of the operating fun. Sure we hear some of the same people but it is the station that pops in on the low elevation passes that make it special. This seems like the same idea of explaining to a "hamshack on the belt" type the magic of HF. Yes, you have to check the propagation and MUF. What is the best band to talk on. All the things that lead to making contacts with different places on HF. While it would be nice to push up North American VUCC numbers, I just don't see why anyone would want a geo-stationary satellite for ham activities. I can guarantee at least two of my friends are on the local repeater right now. That is great if I have to get ahold of them for something or if I am on the side of the road in a ditch (although the auto club on my cell phone is my preferred mode of choice in that situation). Due to the costs, the is clearly academic, but as we frequently hear rumblings of a GEOSYNC bird (from me too in the past), when I really look at why I like operating satellites, that type of bird would have none of that. I am glad someone brought this up though as it caused me to re-examine my own beliefs about it. Thanks, Tom Schaefer, NY4I n...@arrl.net EL88pb Monitoring EchoLink node KJ4FEC-L 489389 DSTAR Capable APRS: NY4I-15 On Oct 11, 2011, at 10:23 AM, Joe wrote: > Too bad we can't get one of the TV sat people to allow us to have one of > their channels. It would be wide enough to hold hundreds of QSO's at the > same time for sure. And I bet they have at least one that isn't doing > anything at all. > > But of course thats not a ham band either bummer! > > Joe WB9SBD > > The Original Rolling Ball Clock > Idle Tyme > Idle-Tyme.com > http://www.idle-tyme.com > > On 10/11/2011 9:01 AM, Howie DeFelice wrote: >> I agree with much of what Dan, N8GFV, says. Our best hope of a high altitude >> satellite is probably a hosted payload on a GEO sat. To make that viable we >> need to consider the entire mission. GEO satellite operators are a >> for-profit business and every aspect of a commercial satellite has a dollar >> value. The major items are spectrum, power and fuel. Since hams bring their >> own spectrum, that is a no cost item for us. If we need to use satellite >> power then we would need to pay the market rate for the percentage of the >> total satellite resource used for the design lifetime of the satellite, >> typically 15 years. If the payload can be disabled by the operator we may be >> able to negotiate a pay as you go plan so that we don't have to pre-pay 15 >> years worth of power. Developing very power efficient transponder systems >> will reduce our costs. Trading bandwidth for power by using digital >> encoding, strong FEC, regenerative transponders with DSP signal enhancement >> will all aid in the reduc! t! > io! >> n of the power required to close a link. >> The other big cost factor is fuel. As previously stated here, station >> keeping is a critical element in GEO satellites and with the advances of >> component technology, a satellites lifetime in orbit is determined primarily >> by the amount of station keeping fuel it can carry. The more fuel, the >> longer the satellite life, the more time the operator can use to recover >> their investment and make money. Every ounce added to the satellite affects >> the cost of the launch and possibly the amount of fuel that can be carried >> on board. Whether this is the case or not, the added satellite weight WILL >> add to the launch cost that we would have to pay. >> The good news is that the AMSAT community and the satellite operators have >> common interests in making satellites less expensive and more efficient. By >> building on the technology pioneered in ARISSAT-1 we MAY be able to get some >> cooperation from a commercial operator to deploy a technology demonstration >> package as a hosted payload. This might be more probable than one thinks. >> Satellite operators are EXTREMELY conservative and don't deploy new >> technology until it is thoroughly proven. The commercial satellite market is >> running out of real estate. Many of the big operators are at over 80% >> capacity. Since they are for-profit organizations, they are running out of >> product quickly and will not be able to grow their business. All the major >> operators are investing large amounts of money to promote a hosted payload >> business where government and scientific users can bring their own bandwidth >> to a transponder or payload on the operators platform. A low cost, high >> performance, innova! t! > iv! >> e payload COULD be a great advertising tool for a commercial operator. The >> operator would g
[amsat-bb] Re: Geostationary Satellite
Too bad we can't get one of the TV sat people to allow us to have one of their channels. It would be wide enough to hold hundreds of QSO's at the same time for sure. And I bet they have at least one that isn't doing anything at all. But of course thats not a ham band either bummer! Joe WB9SBD The Original Rolling Ball Clock Idle Tyme Idle-Tyme.com http://www.idle-tyme.com On 10/11/2011 9:01 AM, Howie DeFelice wrote: I agree with much of what Dan, N8GFV, says. Our best hope of a high altitude satellite is probably a hosted payload on a GEO sat. To make that viable we need to consider the entire mission. GEO satellite operators are a for-profit business and every aspect of a commercial satellite has a dollar value. The major items are spectrum, power and fuel. Since hams bring their own spectrum, that is a no cost item for us. If we need to use satellite power then we would need to pay the market rate for the percentage of the total satellite resource used for the design lifetime of the satellite, typically 15 years. If the payload can be disabled by the operator we may be able to negotiate a pay as you go plan so that we don't have to pre-pay 15 years worth of power. Developing very power efficient transponder systems will reduce our costs. Trading bandwidth for power by using digital encoding, strong FEC, regenerative transponders with DSP signal enhancement will all aid in the reduct! io! n of the power required to close a link. The other big cost factor is fuel. As previously stated here, station keeping is a critical element in GEO satellites and with the advances of component technology, a satellites lifetime in orbit is determined primarily by the amount of station keeping fuel it can carry. The more fuel, the longer the satellite life, the more time the operator can use to recover their investment and make money. Every ounce added to the satellite affects the cost of the launch and possibly the amount of fuel that can be carried on board. Whether this is the case or not, the added satellite weight WILL add to the launch cost that we would have to pay. The good news is that the AMSAT community and the satellite operators have common interests in making satellites less expensive and more efficient. By building on the technology pioneered in ARISSAT-1 we MAY be able to get some cooperation from a commercial operator to deploy a technology demonstration package as a hosted payload. This might be more probable than one thinks. Satellite operators are EXTREMELY conservative and don't deploy new technology until it is thoroughly proven. The commercial satellite market is running out of real estate. Many of the big operators are at over 80% capacity. Since they are for-profit organizations, they are running out of product quickly and will not be able to grow their business. All the major operators are investing large amounts of money to promote a hosted payload business where government and scientific users can bring their own bandwidth to a transponder or payload on the operators platform. A low cost, high performance, innovat! iv! e payload COULD be a great advertising tool for a commercial operator. The operator would get the payload for zero cost and could also get part of the launch cost subsidized by AMSAT in return for a real world, open source demonstration tool. If we build this payload along the lines of Tom Clark's C-C rider concept with a 5 GHz up/ 3 GHz. down transponder we can probably even use the satellites low gain telemetry antenna, further reducing payload costs. Sorry for the lengthy post but I have been thinking about this for a while and this seemed like a good opportunity to finally put it in writing. HowieAB2S ___ Sent via AMSAT-BB@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@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
[amsat-bb] Re: Geostationary Satellite
I agree with much of what Dan, N8GFV, says. Our best hope of a high altitude satellite is probably a hosted payload on a GEO sat. To make that viable we need to consider the entire mission. GEO satellite operators are a for-profit business and every aspect of a commercial satellite has a dollar value. The major items are spectrum, power and fuel. Since hams bring their own spectrum, that is a no cost item for us. If we need to use satellite power then we would need to pay the market rate for the percentage of the total satellite resource used for the design lifetime of the satellite, typically 15 years. If the payload can be disabled by the operator we may be able to negotiate a pay as you go plan so that we don't have to pre-pay 15 years worth of power. Developing very power efficient transponder systems will reduce our costs. Trading bandwidth for power by using digital encoding, strong FEC, regenerative transponders with DSP signal enhancement will all aid in the reductio! n of the power required to close a link. The other big cost factor is fuel. As previously stated here, station keeping is a critical element in GEO satellites and with the advances of component technology, a satellites lifetime in orbit is determined primarily by the amount of station keeping fuel it can carry. The more fuel, the longer the satellite life, the more time the operator can use to recover their investment and make money. Every ounce added to the satellite affects the cost of the launch and possibly the amount of fuel that can be carried on board. Whether this is the case or not, the added satellite weight WILL add to the launch cost that we would have to pay. The good news is that the AMSAT community and the satellite operators have common interests in making satellites less expensive and more efficient. By building on the technology pioneered in ARISSAT-1 we MAY be able to get some cooperation from a commercial operator to deploy a technology demonstration package as a hosted payload. This might be more probable than one thinks. Satellite operators are EXTREMELY conservative and don't deploy new technology until it is thoroughly proven. The commercial satellite market is running out of real estate. Many of the big operators are at over 80% capacity. Since they are for-profit organizations, they are running out of product quickly and will not be able to grow their business. All the major operators are investing large amounts of money to promote a hosted payload business where government and scientific users can bring their own bandwidth to a transponder or payload on the operators platform. A low cost, high performance, innovativ! e payload COULD be a great advertising tool for a commercial operator. The operator would get the payload for zero cost and could also get part of the launch cost subsidized by AMSAT in return for a real world, open source demonstration tool. If we build this payload along the lines of Tom Clark's C-C rider concept with a 5 GHz up/ 3 GHz. down transponder we can probably even use the satellites low gain telemetry antenna, further reducing payload costs. Sorry for the lengthy post but I have been thinking about this for a while and this seemed like a good opportunity to finally put it in writing. HowieAB2S ___ Sent via AMSAT-BB@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
[amsat-bb] Re: Geostationary Satellites
You are viewing it only from the point of view of signal interference. In reality, the greater issue is maintaining our position and the risk of collision. There is a very tight band that defines geostationary and there are some significant disturbing forces: Earth's triaxial gravity distribution, lunar and solar gravity, and solar radiation pressure. This mandates that there be vigilance in monitoring the satellite's orbit and those of its neighbors and to also have a propulsion system capable of station-keeping on a regular basis. Even without the risk of collision, not holding the position tightly nullifies the benefit of fixed antenna pointing. For those believing in the large space, small satellite theory, the risk of collision is more real than one might think. I could only imagine the legislation and regulations that might be placed on amateur satellites if we failed to control our bird and it collided with a very expensive commercial or government asset. Until AMSAT can build enough experience to operate a propulsion system reliably for the long term, I don't think we can responsibly operate a satellite bus on a congested orbital highway. 73, Ken N2WWD Sent from my iPad On Oct 10, 2011, at 10:59 PM, Paul Williamson wrote: > On Oct 10, 2011, at 3:03 PM, Ken Ernandes wrote: >> 1. There are a finite number of orbital slots at Geostationary. That is >> essentially like water front property. > > I've heard that asserted before, but I question the reasoning. > > My understanding is that spacing of satellites around the geostationary orbit > is dictated by the beamwidth of the ground station antennas. In other words, > it's a matter of spatial frequency sharing. The satellites have to be far > enough apart that a ground station antenna can illuminate one of them without > causing too much harmful interference to the ones in the adjacent slots, > after all the expected errors (orbital and ground station pointing) are taken > into account. > > If that's correct, since amateur radio satellite operate on different > frequencies from the commercial satellites, there is no conflict between > amateur radio satellites and commercial satellites for orbital slots. > > Where have I gone wrong? > > 73 -Paul > kb...@amsat.org > ___ Sent via AMSAT-BB@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
