[amsat-bb] Re: Phase 4

[Robert McGwier]

P4 lite will be roughly 4-5 times more expensive than eagle.  They are 
not giving us power, fuel, a berth, etc. for free.  We will be paying 
for it by various means.  The engineering tasks alone to produce a set 
of payloads that will last "reliably" for 15 years, to be built with 
sufficient quality and confidence that someone will pay us to do it will 
probably be as much as eagle.  The big gain is no solar panels, no off 
pointing,  no motor, no attitude sensors, no attitude control, no real 
time computer to be coordinated down to 20 msec, etc.  The other big 
gain is that we provide credible services that are interesting to those 
who might fund us.  A loss would be that it will park, not move, so 
there will not be much variability.  A gain would be no requirement for 
an antenna rotator unless we get more than one bird and then only a 
polar mount is needed.

There are tons of trade offs and nothing at all is for free.

Bob
N4HY

sco at sco-inc.com wrote:
> Are you kidding?
> Eagle costs millions for us to launch P4 lite is FREE?
> Phase 4 will have 400 watts of power given to us for FREE for 15 years.
> Phase 4 will have engine and fuel and ground control station keeping 
> in a geo sat position for FREE for 15 years.
> All we need to do is build the transponder and enjoy the free ride 
> ... and not to even go begging to find a ride.
> 
> Phase 4 to me should have absolute priority over Eagle, at least for 
> the first P4 (I assume there may be more in the future?).
> 
> Les W4SCO
> 
> At 10:58 PM 10/30/2007, you wrote:
>> Hi Robert (N4HY)
>>
>> I have been reading all the info on the BB about what appears to be a Geo
>> syncronous amateur system supported by a commercial bird.
>> Obviously you and others have done much work to understand this scheme
>> in order to develop support for it.
>> My problem is I do not have enough to really handle this issue as a Amsat
>> Coordinator and was not able to attend the symposium.
>> Being an uninformed Amsat Coordinator is not healthy for Amsat.
>>
>> Is a system level proposal for this new Phase 4 going to be provided with
>> sufficient numbers to allow membership evaluation before any impact on
>> the Eagle system effort is considered acceptable.
>> A question that needs an answer as I have already been asked.
>>
>> Will an analysis of the effects on the HEO DXCC desires of the membership
>> as to the effect of a stationary fixed aperture antenna pattern in Geo
>> versus a moving satellite location fixed aperture antenna system not in
>> Geo.
>> To include the need to use high squint angles and power levels required
>> on both
>> ends of this sort of  link budget.
>>
>> Sorry I did not attend the symposium.
>>
>> Joe Murray K0VTY
>> Amsat # 860
>> Amsat area Coordinator NE
>> =================================
>> On Tue, 30 Oct 2007 20:22:45 -0400 Robert McGwier <rwmcgwier at gmail.com>
>> writes:
>>> We have kept Eagle satellite alive.  The lab at U. Md. ES is being
>>> built
>>> out and we are going ahead with the structure.  We helped fund the
>>> completion of P3E  with our international  partners and stepped up
>>> our
>>> efforts to finish the IHU-3 for them (and us.
>>>
>>> The Eagle satellite structure build out is funded and slated for
>>> completion in 2008.
>>>
>>> We are really going to try to get P3E a ride on Intelsat to balance
>>>
>>> against the other offers to see what is best for AMSAT-DL and us.
>>>
>>> Stefan's analysis is correct.  Any one geostationary bird can cover
>>>
>>> roughly a third of the earth.
>>>
>>> Bob
>>>
>>>
>>>
>>> Stefan Wagener wrote:
>>>> Yes,
>>>>
>>>> It is a great project and deserves our full support!
>>>>
>>>> Having said that we also need to realize, that depending on the
>>> location of
>>>> the satellite above the equator we might only have the Americas in
>>> the foot
>>>> print. No Europe or Africa and no Asia. Since the first
>>> geostationary
>>>> satellite with amateur radio has to provide tangible support for
>>> government
>>>> agencies (funding source) it will certainly be primarily centered
>>> around a
>>>> North American footprint. That's why we need to keep Eagle alive
>>> and support
>>>> Phase 3E.
>>>>
>>>> All together they will give us the full package of worldwide DX
>>> via
>>>> satellite and reliable high power communication in the Americas.
>>>>
>>>> 73. Stefan VE4NSA
>>>>
>>> --
>>> AMSAT Director and VP Engineering. Member: ARRL, AMSAT-DL,
>>> TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair
>>> "An optimist may see a light where there is none, but why
>>> must the pessimist always run to blow it out?" Descartes
>>> _______________________________________________
>>> Sent via AMSAT-BB at amsat.org. Opinions expressed are those of the
>>> author.
>>> Not an AMSAT-NA member? Join now to support the amateur satellite
>>> program!
>>> n settings: http://amsat.org/mailman/listinfo/amsat-bb
>>>
>>>
>> _______________________________________________
>> Sent via AMSAT-BB at 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 at 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 Director and VP Engineering. Member: ARRL, AMSAT-DL,
TAPR, Packrats, NJQRP, QRP ARCI, QCWA, FRC. ARRL SDR WG Chair
“An optimist may see a light where there is none, but why
must the pessimist always run to blow it out?” Descartes