[amsat-bb] New satellies / Shuttle question

[G0MRF@aol.com]

Hi Edward / group.
 
Most current construction or feasility study is centered on P3E / Eagle /  
Intelsat /HEO where launch opportunities are rare and costs are high.
 
Perhaps we should look at this problem from another viewpoint. Start with  
what launch opportunities  AMSAT can afford and then retake the technology  
initative and investigate what minaturised payloads can we launch for that  price?
 
For example.  Imagine a 2 or 3U cubesat type structure, or  even one half the 
size of AO-51 on last weeks Russian launch to  1500km.  With payloads reduced 
to transponders and a basic onboard computer  and an Electrical Power System, 
it would be feasable to put RF comms equipment  into a decent orbit on 29MHz 
145MHz 435MHz with an RX on 1269.
For bands higher than 13cm doppler is a problem and path loss is  quite high. 
 It may not be possible to provide the necessary DC power  for transmitters 
in a small structure.
 
Talking of DC power, the number of cubesats that fail due to power problems  
is huge. The answer is to get inventive with deployable solar arrays. With  
the engineering excellence AMSAT possesses it should not be impossible to  
arrange a structure where the entire outer layer contains extra solar cells  that 
are deployed after seperation from the launcher.  Imagine a  3U cube which in 
orbit becomes a 3U box of electronics covered in cells, with an  extended outer 
3U shell that deploys forming a 6U structure producing  nearly double the DC 
power. The 6U structure also makes antenna design  easier
 
For a slightly more risky idea.....small satellite propulsion.  Again,  
perhaps 3U cube, with the last section comprising a small motor. A single burn  
unit could provide a really nice elliptical LEO orbit, perhaps 680km to  2000km.  
Wouldn't that be interesting.  I notice that there is an  Austrian university 
team who have developed a cubesat sized ion propulsion  system asking if 
anyone would like to try it.  So, while this may initially  seem a 'wild idea'  it 
is based on technology that is very nearly a  reality.
 
Worth investigating?   
 
David  G0MRF
 
 
In a message dated 30/05/2008 23:22:37 GMT Standard Time, vk3jed at gmail.com  
writes:

At 12:15  AM 5/31/2008, Edward Cole wrote:


>Once you total the costs it  may actually be cheaper to build a new
>satellite and launch  it!
>Back the effort for P3E and Eagle/P4.

That too, yes, a new  bird would be the easiest approach 
indeed.  Still, as I said, it was  interesting contemplating how such 
a recovery might be achieved with  today's technology. :)

73 de VK3JED