[amsat-bb] Re: Can we get them to fix AO-40 first then?

Edward Cole kl7uw at acsalaska.net
Thu Oct 15 21:34:05 PDT 2009

So, IF the battery un-shorts, IF the IHU boots 
and resets the beacon (S-band, I 
assume).  Therefore, for the rest of us, 
occasional monitoring the beacon frequency would 
be good (using the current keps to estimate 
Doppler offset).  IF detected, then commands 
could be attempted.  Sounds like a lot of 
IF's.  Is this a good reason to keep your S-band 
downlink equipment working?  Think about it.

Integrity of S/C is unknown, so its all a big guessing game.

I remain available (when QRV on L-band with 865 
kW EIRP) for command attempts (lat=60.675N, Lon=151.316W).

73, Ed - KL7UW

At 07:20 PM 10/15/2009, Rocky Jones wrote:

>Hello Peter and thanks for the reply...sorry mine was so late, busy afternoon.
>you answered my question.  I had "heard" that 
>with the arrays folded or based on some 
>failures...that AO-40 did not have 360 degree 
>coverage in solar cells around its spin access.
>If that was the case then the battery was going 
>to be essential for any type of recovery...but 
>since it is not accurate then I agree if the 
>battery will open (do a "seven") then the only 
>question would be the Solar angle.
>Thank you for a very good and straight forward answer  73
>Robert WB5MZO
> > Date: Thu, 15 Oct 2009 23:30:03 +0200
> > From: peter.guelzow at kourou.de
> > To: orbitjet at hotmail.com
> > CC: samudra.haque at gmail.com; amsat-bb at amsat.org
> > Subject: Re: [amsat-bb] Re: Can we get them to fix AO-40 first then?
> >
> > Hi Robert,
> >
> > that's indeed the big question...   We do not know in which attitude the
> > spacecraft is..  is it still spinning very slowly or tumbling?  What is
> > the Solar-ß-Angel?
> > If the S/C has a good orientation to the sun and the battery opens, than
> > there should be enough power to operate the IHU and Beacon etc... do
> > some magnetorquing to improve attitude.
> > Something like this was done when AO-10 was hit by the last rocket
> > stage, spinning the wrong direction with sun directly on top and almost
> > no power...
> > Unfolding the solar panels would give very high power only when they are
> > oriented towards the sun.  With folded solar arrays, all panels around
> > the satellite can still see the sun around it's spin axis.
> > Only when it shines on top or bottom, we will have problems...
> >
> > 73s Peter
> >
> >
> >
> > Rocky Jones wrote:
> > > Peter.
> > >
> > > In the current configuration (or the last known config) of the vehicle
> > > does the vehicle have sufficient solar illumination to "spin" and
> > > maintain the DC busses without a battery?
> > >
> > > Robert WB5MZO
> > >
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73, Ed - KL7UW, WD2XSH/45
  BP40IQ   500 KHz - 10-GHz   www.kl7uw.com
500-KHz/CW, 144-MHz EME, 1296-MHz EME
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