Hi Auke / Don

I believe in the case of AO-40, there is potential damage from a corrosive fuel 'leak'.

Regarding battery protection. For smaller satellites an optically switched solid state relay between the battery and the satellite bus looks to be a good idea.

Any time the battery has an EMF of greater than 2 volts the relay is 'on' and its MOSFETS connect the battery to the system.

If the battery volts go below 2V then the relay goes 'open' and the battery is disconnected from the satellite allowing power from the BCR to go directly to the payloads.

You could also send a command to switch the relay back on to recharge the battery at a later date.

Would be nice to try all this some day. Several years of normal operation followed by several years of daylight only sounds good to me.

Talking of daylight only....Hopefully only 6 weeks to the Delfi3c launch!

73

David

Someone else my be able to correct my understanding if I have misunderstood the AO-40 design. Hopefully those who designed the power system have moved on and we now have some better insight.

Don

In a message dated 02/03/2008 04:06:59 GMT Standard Time, sparkycivic@shaw.ca writes:

I presume that they are in a fail-close arrangement, because if they were fail-open, they should have already done-so due to the shunted power system. Also, could the solar panels have fuses that have opened? could such fuses be re-settable?

I would be interested to hear what knowledge there exists about the present status of AO-40, especially what "google" couldn't fetch.