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Re: An Open Letter To AMSAT



>>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 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.

It all depends on which command was the last one the satellite 
received .. there is a fixed timeout from the last command received, 
but which command that was is anyone's guess.  If the satellite 
receives any commands, that will reset the timer and delay the 
timeout that brings the satellite into command-assist mode, thus 
making it more difficult to reestablish telemetry and get a data dump 
that may have information on why the telemetry dropped out.

As for this being rocket science, well .. commissioning a new bird is 
sort of like learning to drive a car you've never seen and has never 
been driven before, with the added challenge that the car is of a 
completely unique design and has untested and somewhat unpredictable 
characteristics.  Oh, and your first trip takes you into a huge 
desert thousands of miles from the nearest garage and you can't 
afford to break *anything*.  The audience in the back seat doesn't 
help either.  Patience is everything when you're dealing with 
spacecraft -- any mistake may well be your last ..

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