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

Luc Leblanc lucleblanc6 at videotron.ca
Mon Oct 12 00:24:06 PDT 2009

On 12 Oct 2009 at 8:50, jari.koivurinne at aina.net wrote:

> > I'm no expert on AO-40, but to the best of my knowledge, the solar panels
> > are not retractable - they are fixed in place.  The satellite cannot be
> > commanded "on", as the shorted batteries shunt virtually all of the solar
> > panel output, such that either the command receiver is not operating at
> > all,
> > or there is simply not enough juice to switch anything.  Our best hope is
> > that someday, the batteries will fail open, just as AO-7's batteries did,
> > and AO-40 comes back to life when adequately illuminated.
> >
> > George, KA3HSW
> >
> Four of the solar panels are retractable but not released. Please see some
> old pictures.
> As the orientation of AO-40 is not known it is better that the panels are
> kept around the satellite. If they still exists...
> There is enough power from a single panel to run IHU and some beacon if
> the bus wires and electronics are not damaged. Some sensors indicated that
> sun is shining into the satellite so there may be big hole(s) in it.
> Not sure about that raport though. Have to check out that.
> The beacons were loud with the omnis and data was easily received with
> rubber duck and hand held radio. Miss that fine telemetry sound.
> I have allways said that the world would be different if AO-40 were alive.
> Jari, OH3UW

Just an excerpt from the amsat-dl AO-40 status page  http://www.amsat-dl.org/journal/adlj-p3d.htm

"The BCR's are designed to function with the solar panels extended, when they have to handle over 3 times the power available in spin 

You can also have a pretty good idea of AO-40 life at http://en.wikipedia.org/wiki/AO-40.

Is AO-40 will be a next AO-07 in 30 years from 2004 lets say in 2034? just reading back this catastrophic event period i note this.

" --W4SM for the AO-40 Command Team

PERSONAL NOTE : Like my colleagues on the command team, I have lived and breathed AO-40 for over four years. All of us can almost mentally 
decode 400 bps PSK. We hear it in our sleep. I was watching the battery voltage telemetry at the exact moment that the voltage dropped 
precipitously. In my "day job" I have frequently watched catastrophic events unfold in human beings, and the feeling was EXACTLY the same. 
Part of my day job is to have to make quick decisions during times such times, decisions that can have serious consequences. I was 
instantly aware that we had a serious power event, and I considered cutting the main battery loose and trying to run on the nearly 
completely discharged and untested under load aux. battery. However, because I did not have a clear understanding of where the primary 
fault was, I elected to watch things and try to figure out what was happening. The general rule of, "when in doubt wait to understand" 
works most of the time... In this case it didn't, and I'd sure like to live those minutes over again and cut the main battery loose. 
Hindsight is always 20-20. Of course, if it had crashed anyway, then I'd really be beating myself up. If it's at all possible to bring AO-
40 back, we will. If the voltage is clamped low and there is no other damage, we may end up waiting a long time for a cell to "open", 
hopefully not as long as for AO-07. ..or it may happen today. No success for even weeks or months does not mean that we won't eventually be 
successful. We will sure keep trying. Several of you have written very nice notes of support. Thank you." 

I have a question in mind since that time. Is an open cell event as the one happens in AO-07 can in the last AO-40 batteries context and 
condition enable enough power/voltage-current to bring the satellite to some sort of life?


Luc Leblanc VE2DWE
Skype VE2DWE


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