It has been a while since the last time I wrote an update about Tianwen-1’s attitude. In that post I showed that Tianwen-1 had changed to a sun angle of 0 degrees with respect to the spacecraft’s X axis on 2020-10-22. Since then, nothing changed, even after the spacecraft arrived to Mars orbit on February 2021, so I have been sloppy and ignored the ADCS telemetry for quite a while.
As you may have heard, the 20 metre antenna at Bochum observatory had a failure at the beginning of June due to a thunderstorm. It has been under repair until the end of August, when it became operational again. As AMSAT-DL has now returned to receive telemetry from Tianwen-1 at Bochum, I am now reviewing the new data to see if anything interesting might have happened in the last months.
I have updated my attitude study Jupyter notebook, since the previous version assumed that the spacecraft’s state vectors were heliocentric coordinates, so it didn’t work in Mars orbit, due to the change to Mars-centric coordinates.
When plotting the new data I have learned that Tianwen-1 changed attitude during the release of the lander on May 14, and has maintained this new attitude until the present day.