ACE Weekly 02/21/03 - 02/27/03 All ACE spacecraft subsystems are performing nominally. An attitude maneuver was performed on 02/24/03 successfully. The next attitude maneuver is scheduled for 03/04/03. ============================================================================ Orbit Event: SEV Transit On 03/06/03, at 1754Z, ACE will begin a Solar Exclusion Zone (SEV) transit that will conclude on 03/20/03 at 1518Z. The minimum SEZ angle of 2.68 degrees will occur on 03/15/03 at 2326Z. NOTE: Be advised that telemetry dropouts may occur during this time period. The next expected SEV transit is to occur: Entry: 06/01/03 at 1442Z Minimum angle: 2.18 degrees on 06/13/03 at 1618Z Exit: 06/25/03 at 1652Z ============================================================================ OCRs Executed: NONE ============================================================================ Ongoing Activities: TAPS: Trending, Analysis and Plotting System (TAPS) development continues. TAPS Patch 4.1.1. was installed on TAPS #2 on 02/27/03. Testing is progressing on TAPS#2. TAPS#1 is still under control of the development team. ---------------------------------------------------------------------------- Automation (ROBOTT): Moving of the Offline subsystem has been delayed pending approval of updated offline activities and testing of those activities. The release of the Command & Control subsystem has been delayed until completion of WIND/POLAR automation task, new release date is TBD. HSM is currently being tested by the FOT on string 3. HSM has been working well except for a few random problems that need to be addressed. It will go through several iterations before being moved to string 2. Once any piece of the ROBOTT software is moved to string 2, it will referred to as an 'engineering' version and any problems will be documented via CDS. ============================================================================ Anomalies: DOY 03057 (02/26/2003) - ACE Anomaly Report G03-0007 GDS(DSS-27) Problem with Doppler Receiver From 17:00:46 to 17:16:13, the MOC received degraded VC2 data. We also noticed that the DSN RCVR_A_AGC dropped about 3-4 dB from -121dB to -125dB. Around 17:10 the FOT notified DSN of the problem. DSS-27 informed the FOT they had to swap receiver 1 to receiver 3 for the doppler receiver. DSS-27 reported Receiver 1 had started to give them problems. The station attempted to re-acquire MFR1, adjusting the LBW to 300 vice 1000. No improvement on the SNR. The operator then deselected the RER Switch from MFR1 to MFR3. Telemetry SNR improved from 7.5 to 13. IMPACT: NONE, all data was recovered. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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 Pager: 800-425-3174 Fax: 301-286-1729 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~