During the last week Chandra completed the observing schedule as planned.

During the evening comm pass on Mar 20 it was discovered that the ACIS B-side door mechanism was unexpectedly in an enabled state. This put the instrument in an undesired state where a single command could cause the ACIS door to close. A real-time procedure was executed to test the science instrument remote command and telemetry unit and then to command the ACIS B-side door mechanism to be disabled. The cause of this anomaly is under investigation, with a single event upset in the electronics being a possible explanation. There was no impact to ACIS science observations and ACIS has operated nominally since the event.

Another real-time procedure was executed earlier on Mar 20 to perform a full-frame dark current readout of the Aspect Camera Assembly CCD during a standard one-hour comm pass. This was a second demonstration of an operational concept to obtain dark current data more frequently than the current cadence of four times per year.

Chandra passed through a 10 minute, penumbra-only lunar eclipse on Mar 17 with nominal power and thermal performance.

Of note this week was the release on Mar 19 of CalDB version 4.7.8. This upgrade includes updates for the ACIS T_GAIN files and the HRC-S GAPLOOKUP (degap) tables.

The schedule of targets for the next week is shown below and includes an observation of Jupiter coordinated with Juno.