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Re: Troubleshooting the bird





sco@sco-inc.com wrote:
> 
> At 04:58 PM 12/19/2000 , you wrote:
> >The statements about the "command asssist" mode make it quite clear that this
> >cycles through various combinations of antennas, transmitters and receivers.
> >That's why the command team tried sending "blind" commands.  Since they
> >don't know
> >if the spacecraft heard one without responding it's necessary to wait
> >another ten
> >orbit period to see if the software reset will work and then see if a blind
> >command will be recognized.
> 
> I would think that a good system would try to re-establish contact with
> ground control if after X days no contact had been received. In other
> words, why have a system that just waits for input? Why not have the system
> attempt to transmit coded requests to ground control to re-establish
> control and act in a proactive manner? The beacon would be saying ... "Here
> I am, I have not heard from you, where are you? ... PLEASE CALL" That way
> ground stations would know that the sat had lost contact with the ground
> and start reset actions.

That's exactly what the COMMAND ASSIST task is doing.  If no valid command
was received by the IHU for X orbits (in our case 10 orbits), than it 
will do the above.. call on all the possible frequency/antenna combinations
and try different command RX etc..  Indeed, it will do this only if the
software has'nt crashed..  if the software did crashed, a Reset command
sequence needs to be sent..

Blind commands were sent last night after the new reports of signals on 70cm,
including setting X to 1 orbit just in case..

73s Peter

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