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Re: amsat-dl statement



At 11:26 PM 2000-12-17 +0100, Peter Guelzow wrote:

>This is also not correct and there might be a misunderstanding.
>
>A timeout was expected on Saturday. There were no observations and
>command stations tried to re-establish communication by sending
>blind commands.
>
>Assuming that no commands have been accepted by the IHU-1 since contact
>was lost on Wednesday, a COMMAND-ASSIST watchdog will be invoked
>at orbit=65, MA=0 which is 2000 Dec 21 [Thu] 23:55 utc.
>
>The COMMAND-ASSIST routine will cycle through various RX, TX, Hi-gain
>and Low-Gain antennas..
>
>If commands were received by the spacecraft (although we have not
>seen any successful commands so far), than the COMMAND-ASSIST watchdog
>will be reset for another 10 orbits. In this case we may see this function
>happen not before Dec 25.

I was going to post a detailed reply message, but Peter has perfectly 
summarized the situation.  We won't know for sure if the IHU-1 has crashed 
until December 21 or, perhaps, December 25.  Issuing a blind reset command 
before that time has the possibility of making things worse.  Meanwhile, 
the solar angle is good, the BCR's are self-functional and the power budget 
is positive.  There is every reason to move slowly.  If the COMMAND-ASSIST 
software doe not cycle Tx's and Rx's on Dec 21 or 25, then we will move 
forward with other options.

I would also like to say thanks so much to those of you who have sent 
messages of support.  They are very much appreciated by all of us.  To 
those of you who have suggested that P3D was in some way "rushed" to 
launch, I can only say that this couldn't be further from the 
truth.  Remember,  launch of this satellite was delayed for several 
years...  it sat in a shipping container in Kourou, ready to go for 
months.  There is no question that it was fully ready for launch.  When the 
checkout team left Kourou we were completely satisfied that P3D was a fully 
functional spacecraft, ready for flight.  Let me say that again,  this 
satellite had zero known defects at the time of launch, period.  Several of 
the "defects" that have been mentioned, such as "rounding errors" in the 
magnetorquing software are completely expected parts of the checkout 
process.  This is not a "defect", it's a calibration process.   We cannot 
calibrate the satellite properly until it is in space.

The command team remains very hopeful that we can recover P3D, but 
remember, this really is rocket science.  There are no absolute 
guarantees.   If we had been on the Ariane 501 as initially slated, we 
would have been vaporware from the time of launch.

Regardless of the outcome with AO-40, AMSAT needs, and I believe deserves, 
your continued support, now more than ever.
Thanks.


--
  _______________________________________________________________________
  Stacey E. Mills, W4SM    WWW:    http://www.cstone.net/~w4sm/ham1.html
   Charlottesville, VA     PGP key: http://www.cstone.net/~w4sm/key
  _______________________________________________________________________

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