SDO has continued instrument calibration for the past few days. These included an EVE cruciform and guide telescope monthly calibration. During the cruciform scan SDO left inertial mode (an attitude-control mode) and went into sun-acquisition mode. This was traced to a wrong number in a filter that slowly pushed the spacecraft in the wrong direction until an automated response cause SDO to enter sun-acq mode. The number was fixed and the GT calibration was run.
The EVE cruciform and HMI flat field maneuvers will run Wednesday.
This is why we test!