After the last movement of the DAS, we tested a few lock acquisitions to make sure that it was robust enough. The first thing we did was to reload the old offsets of the SDB1 control, to make sure that the OMC was aligned when the SR mirror was aligned. We tested few lock acquisitions (all of them successful until LN2), and then we focused on consolidating LN3_ALIGNED, which was systematically unlocking.

We tried to remove few actions, to try to understand what was the culprit and we realized that commenting the change of filter of MICH and SRCL solved the problem. So we focused on these two actions. We engaged the filter of MICH by hand, which seemed to work, and the ITF unlocked when we engaged the SRCL one, with a low frequency oscillation. Next trial we engaged automatically MICH filter but not SRCL one and it worked. And we engaged then by hand SRCL one with a higher UGF (from 0.24 to 0.28), and it remained stable. However we noticed that the new LOW_NOISE_3_ALIGNED didn't let many time for the UGF servos to work, so we increased the timer to two minutes, to allow some time to the servos to work. We didn't have time to test this, because we had a couple of not-related unlocks (I will take a look tomorrow), so we leave the ITF in LN2 for the night.

Finally we turned on the Etalon loops at 19.39 UTC.