Hi Dominic,
It's a great question!
If the satellite has batteries that can keep the communications payload ON, the satellite can continue to support communications during an eclipse (what we call the time spent in darkness).
Some satellites do not have batteries, so they will support communications only when in the sun (DO-64 for example).
IO-26 has batteries that are pretty old--yet it continues to operate through pretty long (20 mins or more) of eclipse each orbit. So yes, there are examples where the transmitters work through eclipse (IO-26, VO-52, etc.).
For AO-51, it's all about power management--both by the bird and by the command stations. Right now, AO-51 sees sun all the time. Around January 1, it will begin to experience ecslipses again. Its batteries have lost much of their capacity, and we expect that there will be enough power to keep the computer alive during eclipses, but the transmitters will need to be shut OFF. The computer and software onboard AO-51 help do that automatically (for the most part).
Hope that helps!
73,
Mark N8MH
On Fri, Nov 19, 2010 at 8:29 AM, Dominic Hawken dominic@del.co.uk wrote:
Probably a dumb question and still new to this - apologies in advance. Am I right in thinking the amateur sats switch comms off when not in sight of the sun? Are there any that continue to run in darkness?
Best,
Dominic G6NQO
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