[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: Troubleshooting the bird



Since the description of  "command assist" from the command team includes
"transmitters" it may very well do just that.  It could be that the spacecraft
transmitted on a frequency that no one was listening to.  It could be that
something did change the attitude and the antenna for a working transmitter wasn't
pointed the right way.  There's a multitude of possibilities that come to my mind
and however many I can come up with I'm sure the people on the command team who
are vastly more knowledgeable about satellites in general and AO-40 in particular
can think of many more.

The way I read the bulletin was that after they tried blind commands after they
didn't hear the satellite.


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.
>
> W4SCO

----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home