The attitude of AO73/FUNcube-1 is passively stabilised using the traditional magnet and two hysteresis rods. Since the launch over four years ago we have been intrigued with the resultant actual spin rate/period which seems to vary over time for reasons that have not yet been properly explained.
This graphic, which has been developed from telemetry received and maintained by Colin, VK3IH, and his team, shows the variations in some detail. Explanations would be gratefully received.
As it is expected that illumination levels may be having an influence, the next few months and years will prove interesting. The spacecraft will be entering periods of continuous sunlight. Initially this will be for a six-week period but then for periods of up to nine months!
This illustration from Mike, DK3WN’s, illum.exe software shows the predicted duration of the first period.