During the last week the observing schedule was interrupted on Sept 1 at 6:34 a.m. due to a failure indication in the LETG software logic. Preliminary assessment is that the grating inserted correctly, but 0.3% faster than the software expected. This resulted in contact with the mechanical stop, which left the insert microswitch in the wrong position, leading the OBC software to declare the move a failure. This prevented further OTG motions and resulted in several misconfigured observations before SCS 107 could be executed to stop the science loads. Observations impacted by the interruption will be rescheduled in a future week.

A real-time procedure was performed on Sep 1 which cleared the "last move failed flag" which is required to move the gratings. A second real-time procedure was completed on Sep 2 to retract the LETG in preparation for resuming science. Science loads resumed Sep 2 at 4:37 p.m EDT.

A press release was issued Aug 31 describing observations of the black hole system MG B2016+112. Using Chandra observations and radio based modeling, observers have concluded that the three X-ray sources they detected from the MG B2016+112 system must have resulted from the lensing of two distinct objects. These two X-ray-emitting objects are likely a pair of growing supermassive black holes or a growing supermassive black hole and its jet. For details see: https://chandra.harvard.edu/press/21_releases/press_083121.html

The schedule of targets for the next week is shown below and includes observations of Jupiter coordinated with HST.