FUNcube-1 (AO-73) Spin Period

Last weekend FUNcube-1 (AO-73) reached the milestone of having been in space for 100 days – actually that should be clarified to mean “terrestrial” days as the spacecraft itself has been subjected to more than 1500 day/night cycles during this time.

FUNcube-1 (AO-73) – Image credit Wouter Weggelaar PA3WEG

We are very grateful to the 500+ stations who have been providing FUNcube-1 telemetry data to our Data Warehouse. We now have more than 1GB of data in the repository – this is an amazing effort and achievement from a spacecraft which is only transmitting at 1200bps. Thanks everyone and please keep it coming:)

From all the telemetry we can see that the spin rate decreased for a time but now is speeding up again. External temperatures span a range of 50C between the end of the sunlit phase and the end of the eclipse period. Even inside the spacecraft the temperatures range over 25C.

All the subsystems continue to work well and are “well in the green”.

The increased solar activity is certainly having an effect on the downlinked signal on many occasions. During such disturbances the signal appears to be being affected by ionospheric scintillation which distorts the BPSK stream and makes decoding much harder for some minutes at a time.  This effect is not just apparent near the magnetic poles as can be seen in this paper:  http://waas.stanford.edu/papers/IWG/sbas_iono_scintillations_white_paper.pdf

Users in the Northern hemisphere will have noticed that the evening passes in amateur mode are becoming shorter as the spacecraft enters sunlight again near the pole. This effect will increase as the season progresses and we will be testing a plan to change the operating schedule in a few weeks time. This test will involve placing the spacecraft into continuous amateur/transponder mode for a number of orbits – probably over a weekend.

Especially for educational users of FUNcube, we have placed all our schools outreach material on one page for easy reference. It can now all be found here: http://funcube.org.uk/education-outreach/