ACE Weekly 09/06/02 - 09/12/02 All ACE spacecraft subsystems are performing nominally. An attitude maneuver was executed this week with no problems to report. The next attitude maneuver is scheduled for 09/13/02. ============================================================================ OCRs Executed: NONE ============================================================================ Ongoing Activity: The engineering test to determine the new HGA constraint is continuing. The current constraint is 6.0 deg., with current tests reaching 6.5 degrees. The FOT has been monitoring the Signal Strength, the MFR AGC levels, and the Signal-to-Noise Ratios(SNR). The drop in RF levels from an HGA angle of 0 deg to 6 deg has been approximately 3dB. There has been no loss of telemetry due to the increased HGA angles. Analysis is ongoing to determine new HGA angle constraint. The following HGA angles and range values are from FDF. Man Date Pre Man Post Man Earth-ACE Range 03/28/02 -4.58 deg +4.38 1408287 km 04/04/02 -4.35 +4.50 1414808 04/11/01 -5.09 +3.79 1428491 04/18/02 -5.16 +3.85 1440512 04/26/02 -5.77 +5.56 1455949 05/06/02 -5.72 +5.43 1493008 05/17/02 -5.81 +5.31 1527979 05/28/02 -4.34 +4.88 1550263 06/06/02 -2.38 +5.96 1576064 06/20/02 -6.57 -3.66 1590405 06/26/02 -6.43 +5.94 1592458 07/12/02 -6.5 +6.5 1598879 07/30/02 -6.5 +6.5 1567441 08/13/02 -5.34 +6.43 1532343 08/23/02 -3.28 +4.64 1493746 08/30/02 -4.12 +6.36 1475423 09/06/02 -5.20 +6.2 1457788 ============================================================================ TPOCC Release 5.2 String 1 Status TPOCC Release 5.2 was installed on String 1 on 9/5/02. Realtime operations have been transferred to String 2 (with String 3 as backup). String 1 testing is in progress and should be completed by 9/20/02. No major issues to report at this time ============================================================================ Anomalies: DOY 02250 (09/07/02) ACE Anomaly #S02-0020 S3DPU_CONV_SEC_I Limit Violation S3DPU_CONV_SEC_I violated the Red High Limit twice for 2-3 seconds at a time. Mark Popecki was notified and said it was probably due to the recent solar activity. IMPACT: NONE DOY 02251 (09/08/02) ACE Anomaly #G02-0103 D24 Complex Software Problems The first command in g_initial_contact (Bin Clear) failed to be transmitted to the spacecraft. The FOT contacted D24 and they said they had to reboot the exciter. That apparently did not work because then they had to reboot the TSP (Transponder Plus) for the Complex Software system. Commanding was delayed by 30 minutes while D24 was troubleshooting the problem. AOS was at 15:20:03 and commanding was not available until about 15:50. IMPACT: None. All data was recovered. DSN DR# G101578 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Glen A. Miller Honeywell Technology Solutions Inc. ACE Flight Operations Team Goddard Space Flight Center Building 14, Room W10A Mail Stop 428.2 Greenbelt, MD 20771 Office: 301-286-7071 Fax: 301-286-1729 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~