ACE Weekly 04/02/04 - 04/08/04 All ACE spacecraft subsystems are performing nominally. An attitude maneuver was successfully executed on 04/02/04. The next attitude maneuver is tentatively scheduled for 04/14/04. ============================================================================ Orbit Events: From Craig Roberts (FDF): The next ACE transit of the old Solar Exclusion Zone (SEZ) will run from 05/19/04 to 06/14/04. For the first time ever, ACE will transit the solar disk on 06/01/04. On that date, the Sun's angular radius is 0.2629 degree (as seen from Earth's center). The solar transit will last nearly 21 hours (again, as seen from Earth's center). The main features of this transit are given in the following table (times are UTC). 5/19 01:42 4.75 deg inbound 5/27 07:45 2.0 deg inbound 5/30 23:39 0.63 deg inbound 6/01 01:18 0.2629 deg (kissing solar disk inbound) 6/01 10:46 0.197 deg (radius of closest approach to solar center) 6/01 22:14 0.2629 deg (kissing solar disk outbound) 6/02 23:28 0.63 deg outbound 6/06 11:15 2.0 deg outbound 6/14 07:18 4.75 deg outbound The 0.63 deg epochs are included because that radius represents the closest approach during our last transit in February/March. ACE will spend almost exactly 3 days within this zone. ===================================================================== OCRs Executed: None ===================================================================== Ongoing Activities: TAPS: - Transition from GTAS to TAPS occurred on 03/18/04. All trending activities are being accomplished using TAPS. No problems have been noted to date. ---------------------------------------------------------------------------- Automation (ROBOTT): - Testing of Release 0.5 is progressing well. This release will not be placed on String 1. - Failover monitor/CRON testing began 03/19/04 with some minor problems identified. - ROBOTT Release 0.6 is scheduled for installation on String 2 on 04/09/04. This release will not include any GTAS tasks and will include any fixed DRs at that time. ============================================================================ Extra Spacecraft Activities: - Received final OCR from M. Popecki for the S3DPU Anti-Reset Patch activity. All loads have been built and reviewed by both M. Popecki and the FOT. SWICS/SWIMS OCRs for Latchup Recovery have been reviewed and finalized based on inputs from Jim Raines. Uploading of the Anti-Reset patch will occur on 04/09/04 with M. Popecki(SEPICA) and S. Lasley (SWICS/SWIMS) monitoring the activity. ===================================================================== Anomalies: DOY 04095 (04/04/04) ACE Anomaly G04-0025 - MAD 26m DSS-66 - X-Axis Hydraulics Failed X-Axis Hydraulics on DSS-66 failed at 16:00. Telemetry offline at 16:15 for the rest of pass. IMPACT: Unable to complete pass activities. Telemetry subsequently recovered on next day's pass. DR# M102404 DOY 04095 (04/05/04) ACE Anomaly G04-0026 - MAD 26m DSS-66 - Station RED At 13:30, the DSN Ops Chief informed the FOT that station DSS-66 was RED. Station DSS-27 was able to provide coverage for the pass (BOT 14:45/ EOT 18:15). IMPACT: None. All pass activities completed. DR# M102408 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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 gamiller@pop500.gsfc.nasa.gov ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~