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SEDSAT in Nov.30-Dec.1 (Last Hopes)



Mineo and Everyone

Thanks again publicly for the great job you are doing getting data for us.

It seems that we may be nearing the end of our efforts to recover the bird.  I have found out that one of the two mode L receivers on board the satellite was non functional when it was launched.  This was due to the removal of a part during final integration of the bird due to a fit problem.

There is a strong possibility that this was the main receiver.  The second receiver, even if it is working may be useless.  As you all know there are several receivers on most of the UoSats. SEDSAT is designed in the communications section exactly the same.  It turns out that part of the initialization sequence was not implemented for the second receiver by the UAH team for unknown reasons.  

There is a possibility, outlined by Harold whereby we may be able to get around this problem but it will require some very close coordiation with the beginning of the operating period after the satellite comes out of its safe mode.  As Mineo has correctly pointed out, SEDSAT "live" time is increasing.  It is my theory that this is due to the day/night cycle ratio increasing.  If the bird gets to 80/20 day/night the bird will go power positive until that ratio drops below about 78/22.  The 80/20 ratio is possible. I will drop the bird into STK and figure out when this will be.

Oh well at least we are getting some very good engineerig telemetry from the bird that is giving the NASA guys some data in which to evaluate the Nickel Metal Hydride batteries. Not a total loss.

Please, those who are copying data continue to do so. It is very important and we may be able to figure out a way to get around some of the known problems with the uplink receiver.  I want to also thank Harold for his diligent combing through the code that found the software problem.

There are still a couple of other things that we will try but since we have the best teams in the world in satellite operations in Jim White, Tim Cunningham, Graham Radcliff and others trying the bird, the hope of recovering the bird is dimming. Crap.



Dennis
KD4ETA


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