Tumbling bright satellite: possibly Zi Yuan 2 or Cosmos 1689 Rocket

Hello,

Does somebody know if Zi Yuan 2 or Cosmos 1689 Rocket is tumbling?
Period about 6 sec (+/- 2 sec), very pronounced sequence of one bright
peak and one less bright peak. Something like this?

I'm asking because today we saw an unusually bright tumbling satellite
and heavens-above.com shows two very similar passes by Zi Yuan 2 and
the Cosmos rocket. Both fit the trajectory and are within the accuracy
limits of the time we took (we did not have exact time at the moment;
probably +/- 3 minutes). I'd like to see that one again.

Thanks,

- Alex