Merry Christmas to all my fellow space enthusiasts
Nice to see some informative Big Picture discussion here.
For all its worth; I believe a cooperative effort with an established satellite builder incorporating an auxilliary payload makes more sense than an independant effort with more complexity and cost.
Who really would'nt want a geosynchronise transponder?
Utility costs less than pride!
I'm extremely impressed with what amsat can do but a cooperative effort would be more practical with a greater chance for success.
I would put my meager resources towards a professional venture more than a risky one.
On another note; great to see amsat working on a new power system with the super-caps.
Happy holidays to all, pat
At 11:21 AM 12/12/2007, Patrick McGrane wrote:
Merry Christmas to all my fellow space enthusiasts
Nice to see some informative Big Picture discussion here.
For all its worth; I believe a cooperative effort with an established satellite builder incorporating an auxilliary payload makes more sense than an independant effort with more complexity and cost.
Agreed, more efficient use of resources.
Who really would'nt want a geosynchronise transponder?
One? Probably not (odds are it would be parked over the Atlantic, a useless location from here). 2 or 3? Definitely (global coverage, except near the poles).
73 de VK3JED http://vkradio.com
At 04:06 PM 12/11/2007, Tony Langdon wrote:
At 11:21 AM 12/12/2007, Patrick McGrane wrote:
Merry Christmas to all my fellow space enthusiasts
Nice to see some informative Big Picture discussion here.
For all its worth; I believe a cooperative effort with an established satellite builder incorporating an auxilliary payload makes more sense than an independant effort with more complexity and cost.
Agreed, more efficient use of resources.
Who really would'nt want a geosynchronise transponder?
One? Probably not (odds are it would be parked over the Atlantic, a useless location from here). 2 or 3? Definitely (global coverage, except near the poles).
73 de VK3JED http://vkradio.com
Good points! Most of you probably do not realize that geostationary satellites are not high in the sky from high latitudes. From my QTH (60.7 degrees north) the maximum elevation angle to the Geostationary orbital plane (also called the Clarke Belt) is 21 degrees. That is to a satellite positioned over the latitude of Hawaii (Longitude 150). If the satellite is parked too far east or west, it will be below the horizon to us. That is true equally to north and south hemispheres.
I have written this before. The reason the Phase-3 satellites were so popular was that they were in highly inclined orbits (to the equator). Geostationary orbits are not inclined at all (ideally zero inclination).
This does not mean I am apposed to P4A. I am thoroughly in favor as it is a great opportunity. But designers do need to realize the impact for access to them (and I am sure they are aware). The rest of you need to think about it to see the difference it will make. NZ, AK, Aust. and Japan all will only be able to access a Pacific satellite. DX range will be quite different than of the Heo (Molinya) orbit. Africa will never be in range of Alaska on Geostationary sats, unless satellite-to-satellite linking is incorporated. We have already heard that this is not being considered.
For this reason I hold on to hope that P3E and one Eagle gets into a high inclined orbit. If not then you can always work me on OSCAR-ZERO since the (Moon) orbit is inclined 26 degrees!
Here is another fact to consider: ISS only reaches 11-12 degrees elevation above our southern horizon. The orbit of ISS is inclined 51 degrees above the equator. Of course partly this is because it is only 200 miles above earth. 23,500 miles is a bit more. The Moon at 250, 000 miles is even more.
How about earth-bound sat-gates to relay between Geo's?
73, Ed - KL7UW ====================================== BP40IQ 50-MHz - 10-GHz www.kl7uw.com 144-EME: FT-847, mgf-1801, 4x-xpol-20, 185w DUBUS Magazine USA Rep [email protected] ======================================
At 04:24 PM 12/12/2007, Edward Cole wrote:
Good points! Most of you probably do not realize that geostationary satellites are not high in the sky from high latitudes. From my QTH (60.7 degrees north) the maximum elevation angle to the Geostationary orbital plane (also called the Clarke Belt) is 21 degrees. That is to a satellite positioned over the latitude of Hawaii (Longitude 150). If the satellite is parked too far east or west, it will be below the horizon to us. That is true equally to north and south hemispheres.
Agreed on that one. here at 38S, that's not too much of a problem over a fairly wide arc.
I have written this before. The reason the Phase-3 satellites were so popular was that they were in highly inclined orbits (to the equator). Geostationary orbits are not inclined at all (ideally zero inclination).
Well, the planned orbit of AO-40 wasn't that great down here. The high altitude segments would have reached a maximum of 20 degrees above the horizon. At the time AO-40 was launched, I had obstructions up to 30-40 degrees up. The orbit it wound up in was _much_ better, but of course as we know, AO-40 died prematurely, unfortunately. I wasn't around for the earlier P3 birds. :( Where I am currently, a 20 degree elevation would be difficult again, with a block of flats forming a major obstruction. Some win, some lose.
This does not mean I am apposed to P4A. I am thoroughly in favor as it is a great opportunity. But designers do need to realize the impact for access to them (and I am sure they are aware). The rest of you need to think about it to see the difference it will make. NZ, AK, Aust. and Japan all will only be able to access a Pacific satellite. DX range will be quite different than of the Heo (Molinya) orbit. Africa will never be in range of Alaska on Geostationary sats, unless satellite-to-satellite linking is incorporated. We have already heard that this is not being considered.
Well, not direct satellite to satellite, but there has been talk of linking via the ground segment, which would be much easier to maintain and upgrade, with all the "intelligence" on the ground.
For this reason I hold on to hope that P3E and one Eagle gets into a high inclined orbit. If not then you can always work me on OSCAR-ZERO since the (Moon) orbit is inclined 26 degrees!
Well, for me, the previous high inclined orbits aren't that interesting, but if both proposals eventually got off the ground (so to speak ;) ), then we'd have a mix of birds to play with. :) As for the Moon, I'm afraid that's outside my capabilities for the forseeable future. :(
Here is another fact to consider: ISS only reaches 11-12 degrees elevation above our southern horizon. The orbit of ISS is inclined 51 degrees above the equator. Of course partly this is because it is only 200 miles above earth. 23,500 miles is a bit more. The Moon at 250, 000 miles is even more.
How about earth-bound sat-gates to relay between Geo's?
That has been talked about, and I support that idea.
73 de VK3JED http://vkradio.com
At 12:06 PM 12/12/07 +1100, Tony Langdon [email protected] wrote:
At 11:21 AM 12/12/2007, Patrick McGrane wrote:
Merry Christmas to all my fellow space enthusiasts
Nice to see some informative Big Picture discussion here.
For all its worth; I believe a cooperative effort with an established satellite builder incorporating an auxilliary payload makes more sense than an independant effort with more complexity and cost.
Agreed, more efficient use of resources.
And when Intelsat decides to turn off power to your payload you're right back out in the cold again, unless you enjoy exchanging grids on Echo.
KB7ADL
I guess as a new fan/operator of the satellites who is currently dumping a large percentage of his paycheck into a HEO ground station infrastructure, I have a few questions and figured here would be the place to ask, as I can't read German and the US AMSAT page just says it's "in construction."
Is there a physical Phase 3E satellite on the ground (meaning, has actual construction begun)? what is the physical status of the project?
And also, it seems as though there is a bit of panic/uncertainity regarding the ability to actually get it in orbit, from a monetary standpoint. Has the funding or budget requirements for this project ballooned that much? I read the explanation of launch prices and it makes perfect sense, but what were the launch prices when the project was initiated?
I mean, what happens if we can't afford to put it up? Is all the construction money wasted? What happens to the bird?
The geosynchronous bird sounds great at first, but I can see where politics would play into its funding and orbit selection, perhaps.
Don't get me wrong - the LEO sats are fun and a great challenge, and I enjoy every contact I manage to scare up, but HEO is what got me into birds in the first place, way back when.
Matt KC4YLV
At 04:21 PM 12/11/07 -0800, [email protected] wrote:
Merry Christmas to all my fellow space enthusiasts
Nice to see some informative Big Picture discussion here.
For all its worth; I believe a cooperative effort with an established satellite builder incorporating an auxilliary payload makes more sense than an independant effort with more complexity and cost.
Who really would'nt want a geosynchronise transponder?
I want to see NA put Eagle in orbit before anything else. They already put Eagle on the back burner once to build a grid-sat.
Looks like waiting to see if the BOD was really serious about doing Eagle before I'd be making any donations to it turned out to be a good decision.
I think the BOD is serious. Otherwise, I wouldn't be sitting here right now working on the Eagle U-band receiver.
73,
John KD6OZH
----- Original Message ----- From: "Vince Fiscus, KB7ADL" [email protected] To: [email protected] Sent: Wednesday, December 12, 2007 18:08 UTC Subject: [amsat-bb] Re: Phase 4 versus Eagle
At 04:21 PM 12/11/07 -0800, [email protected] wrote:
Merry Christmas to all my fellow space enthusiasts
Nice to see some informative Big Picture discussion here.
For all its worth; I believe a cooperative effort with an established satellite builder incorporating an auxilliary payload makes more sense than an independant effort with more complexity and cost.
Who really would'nt want a geosynchronise transponder?
I want to see NA put Eagle in orbit before anything else. They already put Eagle on the back burner once to build a grid-sat.
Looks like waiting to see if the BOD was really serious about doing Eagle before I'd be making any donations to it turned out to be a good decision.
Sent via [email protected]. 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
participants (6)
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Edward Cole -
John B. Stephensen -
jonny 290 -
Patrick McGrane -
Tony Langdon -
Vince Fiscus, KB7ADL