ACE Weekly 06/28/02 - 07/04/02 All ACE spacecraft subsystems are performing nominally. No attitude maneuvers were executed this week. The next attitude maneuver is scheduled for 07/12/02. ============================================================================ Ongoing Activity: The engineering test to determine the new HGA constraint is continuing. The current constraint (as of 6/3/02) is 6.0 deg, with current tests reaching 6.5 degrees. The attitude maneuver on 7/12/02 is expected to target +6.5 deg. 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. Once all analysis has been completed, the new HGA constraint will be determined. 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 (expected) ============================================================================ TPOCC Release 5.2 Testing Status Testing of TPOCC Release 5.2 on String 3 is 70% completed. No major problems identified to date. Target completion date is July 26th. ============================================================================ Anomalies: DOY 02190 (07/09/2002) - ACE Anomaly #G02-0083 JPL Power Outage JPL experienced a power outage at approximately 1415z. No telemetry was received for the duration of the pass from that time. In addition, the MOC lost all command capability with the spacecraft as well. An additional pass was scheduled for the next day and all telemetry was recovered. IMPACT: Science center data was delayed 24 hours. DR# N100528 DOY 02192 (07/11/2002) - ACE Anomaly #G02-0084 Station Communications Processor (SCP) Reboots 1) From 1508-1522z DSN Monitor Blocks were offline. (DR# G101374) 2) From 1633-1636z, 1742-1749z, no telemetry was received from station 16. (DR# G101375) All three outages were due to SCP errors at station 16 which required a reboot of the SCP. All spacecraft telemetry was recovered. IMPACT: No DSN Monitor Data for the first 13 minutes of the pass. *********************************** Glen A. Miller Honeywell Technical Services Inc. ACE Flight Operations Team Goddard Space Flight Center Bldg. 14, Rm. W10A Mail Stop 428.2 Greenbelt, MD 20771 Office: 301-286-7071 Fax: 301-286-1729 ***********************************