[amsat-bb] Re: flash memory on orbit

[Achim Vollhardt <avollhar@xxxxxxxxxxxxxxx>]

Hi Nick,
some problems here, which I don't find adressed by the other replyants:

1. polar orbit.. you will cross the South Atlantic Anomaly (SAA) zone 
twice a day.. look at it like a hole in the earths magnetic shield.. 
spacewalks are planned not being in the SAA, so it is quite an effect.

2. 800km ist substantially higher than 30000ft.. just as a note: over 
1000 km radiation jumps up:

http://www.cubesat.auc.dk/documents/Space_Environment.pdf

3. single event upset happens on a statistical basis.. the avverage rate 
can be calculated, but it may happen on the very first orbit, so you 
have to make sure, that a single event upset is not shutting down your 
system indefinetely.

73s Achim, DH2VA
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