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Re: An Open Letter To AMSAT



on 12/18/00 5:22 PM, sco@sco-inc.com at sco@sco-inc.com wrote:

>> P3D has been launched. It was moved to a higher (60,000km apogee) orbit than
>> planned by a propulsion system problem. 24 hours later the telemetry beacon
>> shutdown. It is possible that one or both of the IHU's crashed. There is an
>> auto-reboot process that could take place anytime during the next 7-10 days;
>> if it does not, ground controllers could upload a command to do a hard
>> restart BUT they'd prefer to wait a few days before doing that.
> 
> I was told last Thursday evening that the sat would "reset" itself last Sat
> afternoon. It is now Monday evening and you say it should reset itself
> sometime in the next 7-10 days.

I fell for the same confusion.  Here is what I have been able to figure out
from what different control team members have said:

1.) Saturday was the START of a sequence where the craft was to have reset
itself allowing commands to be processed.
2.) No commands have been processed so far as we know.
3.) Since no commands have been processed after this "reset" event, the
software watchdog timer is counting down.  On the 21st, when the timer goes
off, the COMMAND-ASSIST routine will start up which will begin switching on
different antennas and different transmitters in a well defined sequence.
4.) In case a partial command was received or partially processed after
Saturday (since the control team DID try to regain control over the
weekend), the watchdog timer may not time out until the 25th or whenever the
second date that was published is.
5.) Finally, if the COMMAND-ASSIST process fails to operate, the control
crew will then conclude that the IHU-1 has crashed.  If this turns out to be
the case, a hard RESET will be issued from the ground.  This will bring the
satellite to the absolute restart point meaning all software, etc. will need
to be reloaded.  It's the ultimate trump card but one they don't want to
use.
> 
> I thought this was what they called "rocket science" ... that someone
> actually "knew" when events were scheduled to happen.  I guess we are just
> waiting to see if AO-40 "decides" if IT will cooperate and re-establish
> communications.

No, there are two of the biggest problems:
1.) Information has not been completely clear on the entire sequence.  So we
outside the control team jump to conclusions and make up what we don't know.
I fell guilty to that as well.  And as far as communications from the team
not being completely clear, let's remember that they all have jobs, families
and other responsibilities besides ham radio.  This is damn hobby after all.
They would rather spend their time trying to get the bird back than
communicate to the BB and answer all our questions.  I have been told that a
more detailed explanation will be out shortly.

2.) We do not know what AO-40 has heard and what it has not.  That is why
there is a question of when the timer will actually reset.  I have a feeling
the control team is not doing anything until after Christmas.  In other
words, they will probably wait to hear the bird.

I hope this helps.

73,

Jon
NA9D

-------------------------------------
Jon Ogden
NA9D (ex: KE9NA)

Member:  ARRL, AMSAT, DXCC, NRA

http://www.qsl.net/ke9na

My President is George W. Bush -> The legal winner in Florida

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