During the last week Chandra's observing schedule was interrupted by a spacecraft Safe Mode event that occurred at 9:54am EDT on Oct 10 and was detected at the start of a scheduled contact at 10:45am EDT. The Safe Mode transition was nominal and all systems functioned as expected. The cause of the Safe Mode was a trip of the momentum monitor. Analysis of SSR playback data indicated that IRU-2 gyro-2 experienced a glitch in rate data that lasted approximately 3 seconds. This was seen in both channels 3 and 4. The gyro-2 rate glitch then propagated into the OBC internal momentum calculation and subsequently caused the momentum monitor violation that caused Safe Mode. Gyro-1 and all other spacecraft data appeared nominal. IRU-2 has been powered on to assess its status. The plan is to recover from Safe Mode and maneuver to a cooling attitude. The spacecrafts will then be reconfigured to run in a "mixed gyro" configuration using one gyro from each IRU. Once that is complete Chandra will return to science operations.

Of note this week was the Chandra Quarterly Review conducted on Oct 10 in Cambridge.