[amsat-bb] Propulsion equations / Van Allen

[G0MRF@xxxxxxx]

If I recall, particle radiation is also an issue as 7500km would be  
within the inner Van Allen belt.

73 de  VK3JED
http://vkradio.com

Hmmmm.......  Thank you
 
There seems to be a wide difference of opinion about where the belts begin  
and end.
 
I based my figures on the average of seveal web sites.  The key figure  was 
that the lower belt ended at 6000km although this figure varied from between  
6000 and 6800.
 
As Bob N4HY also seemed to think this was an issue, clearly it's an area  
that needs more research.  
 
Where do you put the optimum point? and I wonder how far down the radiation  
intensity curve 7400km is compared to the peak intensity of the lower  belt.
 
I think it would be very difficult to go to 10,000km from a starting point  
of 800k.
 
It makes you wonder how AO7 managed to survive at 1500km for so long.
 
Also, I believe AO10 failed due to the orbit spending too much  time in a 
high radiation environment. But it appears the damage was to the  controlling 
systems of the spacecraft and not the transponder electronics.   Interesting how 
the 'large' transistors in AO10 and AO7 appear to survive, while  the 
'smaller' logic and microprocessor devices fail.
 
Perhaps there are design issues to look at where simple also equals  
resilient?
 
Now where's my valve data book.........Only kidding.
 
Thanks for all the contributions.
 
73
 
David  G0MRF
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