ACE Weekly 04/16/04 - 04/22/04 All ACE spacecraft subsystems are performing nominally. No attitude maneuvers were executed this reporting period. The next attitude maneuver is scheduled for 04/27/04. ============================================================================ 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): - Release 0.6 installed on String 2 on 04/09/04. - FOT testing is almost completed. -- 3 DRs left to verify - two for CRON dealing with pass schedules, one for C&C for the background monitors. Two new DRs have been generated. -- 21 DRs have passed verification. -- 1 DR (color allocation) still needs some work. There are no color issues if C&C is brought up by CRON or the Start Real-Time button. If C&C is brought up with the individual button, there still maybe some color issues, but these do not occur every day. - Installation of the latest release to String 1 is tentatively planned for the week of May 3rd. The date is highly dependent on the FOT's testing progress. - SUG development is ongoing. Tentative release date is the end of May. A DRAFT version may be available prior to that. ============================================================================ Extra Spacecraft Activities: - Executed the S3DPU Anti-Reset Patch activity with Mark Popecki (SEPICA) and Scott Lasley (SWICS/SWIMS) monitoring. To date there have been no problems encountered with the new patch. Mark Popecki continues to monitor S3DPU activity. SWICS and SWIMS should return to NORMAL operations around 04/23/04. ===================================================================== Anomalies: DOY 04111 (04/20/04) ACE Anomaly G04-0028 GDS 26m (DSS-16) VC2 Data Hits - Dropped Blocks At 16:40:32, DSS-16 put telemetry online. Immediately, the ACE FOT noticed VC2 data hits. At 16:48, the FOT informed DSS-16 of the problem. At 16:51, JPL COMM was informed of the situation and stated they would check into the problem. At 16:57, JPL COMM confirmed seeing dropped blocks. The problem continued throughout much of the pass. At 18:16, the VC2 data hits ceased and telemetry was clean from that point. IMPACT: Degraded data throughout most of the pass. Data recovered via CDR file. DR# N102085 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~