ACE Weekly 11/14/03 - 11/20/03 All ACE spacecraft subsystems are performing nominally. No attitude maneuvers were executed this reporting period. The next stationkeeping/attitude maneuver is scheduled for 11/21/03 (See Orbit Events). ============================================================================ Orbit Events: (From Craig Roberts, FDF) ACE stationkeeping maneuver (SK-30) is scheduled to coincide with the next attitude maneuver on 11/21/03. This will be our first SK burn since 6/23/03. The delta-V will be of relatively modest size at approximately 33 cm/sec. A delta-V of this size implies a continuous burn time of about 57 seconds, and would consume roughly 0.223 lbm (0.101 kg) of fuel. The anti-Sunward direction of this delta-V will require the top deck jets 1A and 2A. A few days after SK-30, the next SEZ transit will begin. Its particulars remain basically the same as previously given. Closest angular approach to the Sun will be approximately 0.58 degree closer than the September transit, which was 1.76 deg. To summarize the 24-day transit by epoch and SEV angle: 26 Nov 20:56Z 4.75 deg (inbound) 5 Dec 01:22Z 2.0 deg 8 Dec 18:17Z 1.19 deg (minimum) 12 Dec 19:27Z 2.0 deg 20 Dec 22:00Z 4.75 deg (outbound) ===================================================================== OCRs Executed: None. ===================================================================== Ongoing Activities: TAPS: Release 4.1.11 was delivered on 11/19/03 and is currently being tested by the FOT. The SUG is currently being reviewed by the FOT and SGT. ---------------------------------------------------------------------------- Automation (ROBOTT): - ROBOTT version 0.2 (Offline) is operational on String 1. - ROBOTT Version 0.3 was installed on String 2 (11/05/03) following the FOT verification of fixed Offline and HSM DRs on String 3. The FOT is currently testing the release on String 2. - Command & Control is still being tested by the Automation team and the FOT. - The first draft of the SUG is expected soon. ===================================================================== Anomalies: DOY 03318 (11/14/2003) ACE Anomaly G03-0115 - TPOCC Error Message - Received a message that "snap error ace_cmdstat terminated prematurely", while running G_END_DAY. IMPACT: None. The cmd_stat page printed nominally. DOY 03321 (11/17/2003) ACE Anomaly G03-0116 - GDS 34m (DSS-27) Transmitter Problems At 16:12:04, DSS-27 informed ACE FOT that they were having transmitter problems, a technician was sent out to the site, and they should be up momentarily. Telemetry online at 16:24:25 but no command capability. Command capability established at 16:44:27. IMPACT: Delayed pass activities. All telemetry was subsequently recovered. DR# G103696 DOY 03324 (11/20/2003) ACE Anomaly G03-0117 - GDS 34m (DSS-27) Transmitter Problems At 15:40, DSS-27 informed the FOT that there were problems with the transmitter. No ETA was given as to when the problem would be fixed. Obtained a Short Tracking Pass with Station 46 from 1950 (BOT) to 2125 (EOT). IMPACT: No pass activities were performed during the scheduled Station 27 pass. DR# G103722 DOY 03324 (11/20/2003) ACE Anomaly G03-0118 - GDS 34m (DSS-27) No Telemetry Online Telemetry was not online from DSS-27 until 17:55. At the beginning of the pass, DSS-27 had data type 78 online but the MOC didn't see any coming into the system. After troubleshooting both JPL and NASA networks DSS-27 switched to data type 78 and the MOC finally received telemetry. No command capability because of the concurrent transmitter problem. IMPACT: No pass activities were performed during the scheduled Station 27 pass. All telemetry recovered on later passes. DR # N101618 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Glen A. Miller ACE Flight Operations Observatory Engineer Honeywell Technology Solutions Inc. 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 Email: gamiller@pop500.gsfc.nasa.gov ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~