Around 08:00 UTC, we started the intervention inside the WI tower (69190). Ettore was inside the tower, Cecilia and Ilaria was under the tower, while Luciano and Diana were at the WI base tower / TCS room.

At the beginning of the activity, the VPM process TCS_PAM_WI_PowerSupply was not working properly, and several signals related to PAM on DD remained grey, including the TX/TY motor positions and the actuator voltage/current signals. Giulio came to help recover the situation.

The WI viewport was reported to be in poor condition (69192).

As reference, we used the information from the previous PAM picomotors calibration performed on April 14th, 2026 (68992). 

Following the alignment security procedure prepared by Ilaria and Marco (69189), we switched on the red alignment laser and Ettore checked its position wrt the HR surface of the WI TM. After some alignment steps with the picomotors (Fig. 1), the actuator had been left at the following final motor positions:

• TX = -21555 steps, corresponding to approximately 3.9 cm downward

• TY = -4666 steps, corresponding to approximately 0.7 cm to the left

After the alignment, the red laser was switched OFF and the heater was powered, initially at 6 V and then increased up to about 7–7.5 V, corresponding to roughly 4–4.4 A. Ettore eventually managed to see the mask near the viewport (Fig. 2).

The actuator was finally switched off at 09:41 UTC, setting the voltage back to 0 V, and the activity ended.