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Operations CXO Status Report

Wednesday 18 August 1999 7.00am EST

The following is an overview of the events that occurred over the last 24 hours.

While executing mission sequence load number 3, Chandra entered Safemodes. Initial analysis indicated that the reason for safemode entry was because the Offline System scheduled back to back segmented maneuvers to close together such that the first maneuver did not properly settle out before the second maneuver started. This caused an attitude rate error, which resulted in a successful safemode entry. Redundancy management processes transferred control to B-Side hardware, PCAD control was transferred to the Command Processing Electronics (CPE) assembly, B side On Board Computer (OBC) assumed thermal control and power management, and the ISIM translated (for the first time) to the mid-point safe position. On-site Operations personnel, and members of the Technical Support Team are carefully reviewing and testing recovery procedures on the Test Bed. Safemode recovery on the spacecraft is scheduled to be initiated at 1:30pm EDT today.

Activities for next 24 hours: Recover from Safemode and continue performing SCS directed on-orbit operations.

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