Re: Bill Ress - N6GHz - Board Candidate - OperatingSurvey
At 08:28 PM 7/21/2008, Dave hartzell wrote:
On Mon, Jul 21, 2008 at 9:52 PM, Andrew Glasbrenner glasbrenner@mindspring.com wrote:
Obviously, the GEO is probably the most expensive, with HEO being close to it,
Not necessarily. A small package on Intelsat may be significantly more affordable than Eagle. On the other hand, putting everything from Eagle on Intelsat would likely be more expensive. There are also considerably different risks. Eagle has all the things we've been good about messing up previously, and a Intelsat rideshare has almost none.
As much as I like the idea of an Intelsat ride share, I think there will be too much non-satellite, non-ham stuff involved, e.g. legal things and contracts. What kind of MOUs, memorandums, contracts, etc. are going to be involved? Will hands be tied, due to some kind of required assurance, from either Intelsat or its manufacturer? Will we have to buy expensive insurance, so that if the payload malfunctions and disruptions Intelsat operations, things are covered? What commitments and assurances need to be put into place?
No one knows at this point. Intelsat isn't going to be thrilled with a low-quality product from us, so therefore AMSAT's costs go up, to help minimize their risks.
As Bob B said earlier...there are several tradeoffs to consider, and let me say even the BOD doesn't have the full details to consider yet.
So this is why attaching a "costs vs. benefits" analysis to a simple survey is so difficult!
Personally, I'm in favor of doing whatever project gets us on station with long distance comms first, without breaking the piggybank, or too
much risk.
It is, without a doubt, a very difficult and complicated decision.
I'm glad we can agree on this!
Honestly, thanks for chiming into the BB, Drew. It is my hope that all the other directors are reading.
73,
Dave AF6KD (ex n0tgd)
The Intelsat should be much less expensive: 1-free ride 2-free power 3-free stabilization
All you provide is RF, antennas, and a communication processor.
But the location is specified by Intelsat so only one-third of the earth is covered. Which third do you chose for satellite #1. For whole-earth coverage you need rides to three locations 120-deg longitude apart. Far north latitudes will probably not get coverage due to low angles to GEO.
For my location at 60.7 latitude the GEO path is 21 degrees elevation due south and is lower as you move east or west.
So continuing with Eagle offers world coverage over a couple days of orbiting. GEO stays in one position.
I will see you in Anchorage, Drew!
***************************************************** 73, Ed - KL7UW BP40iq, 6m - 3cm 144-EME: FT-847, mgf-1801, 4x-xp20, 185w http://www.kl7uw.com AK VHF-Up Group NA Rep. for DUBUS: dubususa@hotmail.com *****************************************************
Some replies to Ed's comments:
The Intelsat should be much less expensive: 1-free ride 2-free power 3-free stabilization
Let me clarify this some. It is -not- a free ride. Intelsat will charge us for the loss of operational time for every kg of stationkeeping fuel they offload to accomondate our extra mass. There may be some recurring expenses as well.
All you provide is RF, antennas, and a communication processor.
The good stuff.
But the location is specified by Intelsat so only one-third of the earth is covered. Which third do you chose for satellite #1. For whole-earth coverage you need rides to three locations 120-deg longitude apart. Far north latitudes will probably not get coverage due to low angles to GEO.
For my location at 60.7 latitude the GEO path is 21 degrees elevation due south and is lower as you move east or west.
We most likely would not be dealing with any sort of spot beam and the antennas should be broadbeamed enough so that there is no reason to assume 1/3 instead of almost 1/2. If you could work AO-10, AO-13, or AO-40 near the horizon, the same would likely be true for Intelsat. What would be different is we each could dedicated a fixed antenna with no rotor for ground side, and if you live surrounded by 100' pine trees like I do, you can find an open hole to point through.
So continuing with Eagle offers world coverage over a couple days of orbiting. GEO stays in one position.
While this will maybe make some DXers feel less fulfilled than a HEO, it's my hope that it will attract 10x their number in other users. A GEO knocks 500$ of the top of everyone's station budget right out of the gate...no az-el rotor. Think of the traffic that is likely to be attracted to this...24/7 amateur coverage with set and forget antennas over 1/2 the earth. No Doppler tuning. Practically fixed gain requirements. We may have to find a way to manage the data and repeater system links that will inevitably show up. My gut suspicion is we won't be able to afford enough bandwidth on the first iteration for the users that may come out of the woodwork. If we could just get all the users to support the program...
I will see you in Anchorage, Drew!
The YL and I will be in Anchorage on Saturday evening, then in Seward and Whittier until Thursday or so. I'm looking forward to meeting and speaking with all of ya'll!
73, Drew KO4MA
On Tuesday 22 July 2008 08:11:56 Andrew Glasbrenner wrote:
Some replies to Ed's comments:
The Intelsat should be much less expensive: 1-free ride 2-free power 3-free stabilization
Let me clarify this some. It is -not- a free ride. Intelsat will charge us for the loss of operational time for every kg of stationkeeping fuel they offload to accomondate our extra mass. There may be some recurring expenses as well.
Actually one of the things that makes an Intelsat rideshare more affordable now is that because the launch vehicles have gotten bigger, they typically would not have to offload any fuel due to our small mass increase. However, the increase in mass does increase their consumption rate of station keeping fuel. The resulting reduced operating life expectancy is certainly part of the equation that they will include in quoting prices.
73, Lee-KU4OS
One issue that arose in earlier talks with commercial satellite providers was the fact that the Earth facing side of the satellite was covered with commercial antennas. There was scant little area left to place a significant sized Earth facing amateur radio antenna.
John WA4WDL
----- Original Message ----- From: "Lee McLamb" ku4os@cfl.rr.com To: amsat-bb@amsat.org Sent: Tuesday, July 22, 2008 9:10 PM Subject: [amsat-bb] Re: Bill Ress - N6GHz - Board Candidate - OperatingSurvey
On Tuesday 22 July 2008 08:11:56 Andrew Glasbrenner wrote:
Some replies to Ed's comments:
The Intelsat should be much less expensive: 1-free ride 2-free power 3-free stabilization
Let me clarify this some. It is -not- a free ride. Intelsat will charge us for the loss of operational time for every kg of stationkeeping fuel they offload to accomondate our extra mass. There may be some recurring expenses as well.
Actually one of the things that makes an Intelsat rideshare more affordable now is that because the launch vehicles have gotten bigger, they typically would not have to offload any fuel due to our small mass increase. However, the increase in mass does increase their consumption rate of station keeping fuel. The resulting reduced operating life expectancy is certainly part of the equation that they will include in quoting prices.
73, Lee-KU4OS _______________________________________________ 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
At 04:11 AM 7/22/2008, Andrew Glasbrenner wrote:
Some replies to Ed's comments:
The Intelsat should be much less expensive: 1-free ride 2-free power 3-free stabilization
Let me clarify this some. It is -not- a free ride. Intelsat will charge us for the loss of operational time for every kg of stationkeeping fuel they offload to accomondate our extra mass. There may be some recurring expenses as well.
All you provide is RF, antennas, and a communication processor.
The good stuff.
But the location is specified by Intelsat so only one-third of the earth is covered. Which third do you chose for satellite #1. For whole-earth coverage you need rides to three locations 120-deg longitude apart. Far north latitudes will probably not get coverage due to low angles to GEO.
For my location at 60.7 latitude the GEO path is 21 degrees elevation due south and is lower as you move east or west.
We most likely would not be dealing with any sort of spot beam and the antennas should be broadbeamed enough so that there is no reason to assume 1/3 instead of almost 1/2. If you could work AO-10, AO-13, or AO-40 near the horizon, the same would likely be true for Intelsat. What would be different is we each could dedicated a fixed antenna with no rotor for ground side, and if you live surrounded by 100' pine trees like I do, you can find an open hole to point through.
So continuing with Eagle offers world coverage over a couple days of orbiting. GEO stays in one position.
While this will maybe make some DXers feel less fulfilled than a HEO, it's my hope that it will attract 10x their number in other users. A GEO knocks 500$ of the top of everyone's station budget right out of the gate...no az-el rotor. Think of the traffic that is likely to be attracted to this...24/7 amateur coverage with set and forget antennas over 1/2 the earth. No Doppler tuning. Practically fixed gain requirements. We may have to find a way to manage the data and repeater system links that will inevitably show up. My gut suspicion is we won't be able to afford enough bandwidth on the first iteration for the users that may come out of the woodwork. If we could just get all the users to support the program...
I will see you in Anchorage, Drew!
The YL and I will be in Anchorage on Saturday evening, then in Seward and Whittier until Thursday or so. I'm looking forward to meeting and speaking with all of ya'll!
73, Drew KO4MA
OK Drew,
I probably over simplified the savings.
MY point on viewing a GEO is if it is centered over the east coast of the USA it will be below my horizon. If it is over Europe or central Asia, again no view for anyone on the West Coast of the USA. I have extensive experience with setting up c-band satellite dishes in Alaska and the limits of how far east one can view them. Of course a GEO stationed from Japan to California will be accessible though at the extreme ends the elevation angle will be around 5-degrees and my trees mask the sky at least to 10-degrees. No Holes in the solid forest up here.
Whereas a HEO travels over the pole so lots of high elevation view angles for norhern stations. Less for southern hemisphere, though. GEO is more equal on that issue.
I'm sure that a GEO will be very popular due to the simple ground station set up. I only hope that if we can get one up that I will have a view of it. The only way to assure world wide use with GEO's is to launch three of them spaced around the earth separated by 120-degrees of longitude. So the politics are more sticky for the GEO.
At this point I will be happy with a linear translator satellite in MEO, HEO, or GEO.
73 Ed - KL7UW
participants (4)
-
Andrew Glasbrenner -
Edward Cole -
John Franke -
Lee McLamb