[amsat-bb] COMPASS-1 recovery efforts

Mike Rupprecht mail at mike-rupprecht.de
Sun Sep 7 01:13:58 PDT 2008

Hi all,


Thanks for all the reports and beacons I received over the last 3 weeks.


The Voltage has never climbed over 3 volts (in full sunlight). We can assume
that COMPASS is totally OFF during eclipses.


If COMPASS enters the sunlight she will reboot. Because the low voltage
COMPASS is switching into emergency mode.

That means, that CDHS (Command & Data Handling Subsystem) and ADCS (Attitude
Determination and Control Subsystem) units are completely off. Unfortunately
this means also, that we CAN NOT change the threshold values by commands.


That's the main problem. It seems the satellite is "locked" because in
emergency mode she will accept only two commands: hard reset and TX enable.
Both commands are impractical for recovery.


The only thing we can do is WAIT. Wait for longer sun periods and voltages
over 3.47 Volts. That's the standard threshold value in emergency mode to
switch into powersafe mode. Only in this mode we can change the threshold


We may have lost a cubesat, but we've definitely got some new friends :-)
Thank you all for your efforts!


73, Mike


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