Team:
 

The Eagle Chief Technology Officer (W2GPS), the AMSAT VP Engineering 

(N4HY) and I met (electronically) to discuss the Eagle payload complement.

We have decided the following should be our recommendation to the board of 

directors of AMSAT for their ratification.  This is what will be presented to the BoD:

1.  Services to be provided, as defined at the San Diego meeting et seq:

        Class 0 is linear transponder users

        Class 1 is SMS text message service users

        Class 2 is weak signal voice grade digital channel

        Class 3 is strong signal, large antenna, higher bandwidth signal (think 

compressed full motion video)

2.  Primary class 0 payload:  U/V with a design goal that it be usable over 

75% of the orbit.

3.  Primary class 1 payload:  U/V for the reasons discussed at San Diego.

3.  Primary Class 2 and 3 ACP payload:  S2/C usable over 75% of the orbit.  This 

coverage to be accomplished by using electronically de-spun phased arrays on S2 and C.  

At San Diego, we discussed S2 vs. S1.  S2 was technically superior, but other issues 

caused us to shy away from it.  Upon reflection, the leadership has decided to proceed 
down the technically superior path, S2 uplink.

4.  Secondary Class 0 payload:  L/S1  -if and when the power budget and 

antenna pointing (fixed, nadir-pointing array) can support.  We recognize that it may not be usable 

in many areas due to elevated noise floor resulting from 802.xx devices, as discussed in San

Diego and documented in measurements and analysis.  

NO PERFORMANCE LEVEL IS TO BE PROMISED.

5.  Secondary ACP Class 2 uplink:  A separate L receiver feeding same DSP and C-band 

downlink when fixed nadir-pointing antenna array supports.   This second receiver will share 

the L-band LNA and antenna with the L/S1 Class 0 payload.

The greater level of service for S2 users should encourage people who can to use S2 rather than L.  

NO PERFORMANCE LEVEL IS TO BE PROMISED.

6.  Use of all secondary payloads will be subject to acceptable costs in power, heat, and/or mass,

as assessed by analysis or testing.  They are to be turned off if regulatory constraints are 

imposed post launch.  They will not be flown at all if shown to be not feasible through 

analysis or testing.

This is what I will present to the board at Symposium for their concurrence.  Please contain this 
discussion within the Eagle team until the Board makes a decision.

I request your comments within the next 48 hours so that I can finish the budget tonight and begin 

crafting my presentation to the board and my follow-on presentation at Symposium.  We need to bring 
this to closure so that we can present decisions at Symposium, and move out smartly from there.  Thanks.

Very 73,

Jim

[email protected]

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