Martin is exactly right. Two of the same things is only partial redundancy. In order to be fully redundant the two systems must be independent, built by different teams and have different technology. We can't afford to stumble on this. It seems to me that Mirek has already solved this problem for us.
Lou McFadin W5DID [email protected]
On Oct 3, 2006, at 4:24 AM, Howard Long wrote:
Hi Matt
Why stop there? We should have a backup to the analog transponder in the form of a CW transponder. Then we can back that up with a spark transponder. Finally, we should have some sort of semaphores or smoke signals to back that up.
The point is that the commitment to have an analog backup had already been made. You may not have been party to the discussions around July 2005, but believe me they were just as vociferous as the recent disinformation floating about regarding S1. It is important to consider seriously what the members want - after all, they are paying for it, and there would be no AMSAT-NA or Eagle without them.
Seriously, if we have 2 SDX's, aren't they backups for each other?
Well, this raises an interesting point. My understanding from discussions over this side of the pond with Martin Sweeting is that redundancy only truly exists if you also have two different designs: having two devices of the same design does not resolve design flaws. In SSTL's case, Martin's view is that the majority of failures are now down to design, with a minority environmental (radiation, thermal, outgassing etc etc).
73, Howard G6LVB
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