ACE Weekly 05/30/03 - 06/05/03 All ACE spacecraft subsystems are performing nominally. An attitude maneuver was successfully executed on 05/30/03. The next attitude maneuver is schedule for 06/06/03. ============================================================================ Orbit Events: Currently in SEV transit: 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: EPAM-002 EPAM-003 ============================================================================ Ongoing Activities: TAPS: Trending, Analysis and Plotting System (TAPS) development continues with emphasis being placed on fixing the DRs attributed to the current release. Testing is progressing on both TAPS#1 and TAPS#2. Release 4.1.3 was installed on 05/27/03 but it was determined that a re-release was required because there were some installation problems on both systems (TAPS#1 and TAPS#2). Release 4.1.4 was installed on 05/30/03. A problem was found on TAPS #1 and a re-installation of Release 4.1.4 was required on TAPS #1 on 06/04/03. ---------------------------------------------------------------------------- Automation (ROBOTT): Testing of the Offline and HSM systems is progressing. Testing by the Automation team for Command and Control is still paused due to testing at WIND. The first release of Command and Control to the FOT is still TBD. ============================================================================ Anomalies: Day 03150 (05/30/2003) ACE Anomaly Report #S03-0009 - Mnemonic S3DPU_CONV_SEC_I Red Limit Violation At 16:02:20 and at 16:02:32, the S3DPU_CONV_SEC_I violated the red high limit with a value of 443.186. Notified Mark Popecki. The FOT informed him that there was an X1 class solar flare and an associated CME headed straight for Earth. M. Popecki believes that these event messages are due to the solar activity. He asked the FOT to check the values for the SSDIDLECTR which had dropped down as low as 27 during the pass. For most of the pass, the idle counter was around 42. This in an indication that the S3DPU is collecting a lot of data. Nominally, when there is no solar activity, the idle counter is around 80. IMPACT: NONE Day 03150 (05/30/2003) ACE Anomaly Report #G03-0043 - GDS 26m (DSS-16) Dropped Blocks At 16:15, the FOT informed DSS-16 of degraded data. DSS-16 stated that everything was fine on their end. JPL COM was notified of the problem and stated they could see dropped blocks but no data hits. At 16:22, JPL COM reported that 10 blocks were dropped between 16:05 - 16:16. IMPACT: None. Data was recovered. DR# N101062 Day 03150 (05/30/2003) ACE Anomaly Report #G03-0044 - Problem with Attitude Determination System (ADS) - String 1 When FDF tried to start the ADS software on String 1, it would not start. FDF tried numerous times with the same result. One of the times, ADS was started, but no data was written to the correct files. IMPACT: Since this was a maneuver day, String 2 had to be used by FDF as the primary for obtaining an attitude solution, and String 3 was used as the backup. There were also problems on String 3 (Reference AR G03-0045). Day 03150 (05/30/2003) ACE Anomaly Report #G03-0045 - Problem with Attitude Determination System (ADS) - String 3 When the calc_att script is run on String 3, the output is different than expected. Calc_att on String 2 gives the correct output and this file was used for comparison. Since string 3 needed to be used as the backup for the maneuver (Ref. AR 03-0044), FDF brought up ADS using just the Deterministic, not the Kalman Filter. The ace.startup.ads.ops file in /home/ace/relx.ops/obj_hp/setup/ had been changed when testing was being performed. This file was never changed back to the original. On Day03152 (Monday), the correct ace.startup.ads.ops file was copied from String 1 to String 3. Day 03154 (06/03/2003) ACE Anomaly Report #G03-0046 - GDS 26m (DSS-16) Command Subcarrier Left ON At 15:45 FOT noticed that the command subcarrier was ON from looking at the CLCW_NO_BIT_LOCK mnemonic. DSS-16 set the subcarrier to OFF. When FOT tried a NO-OP command to verify command capability the command was not accepted by the SC. FOT had DSS-16 reconfigure to the NOMINAL configuration. Command capability was subsequently verified by the FOT. IMPACT: None at this time, however subcarrier left ON is non-nominal configuration. DR# G102829 Day 03154 (06/03/2003) ACE Anomaly Report #G03-0047 - GDS 26m (DSS-16) Telemetry Dropout At 17:06 telemetry went offline and stopped flowing from DSS-16. AT 17:17 DSS-16 informed us that they were having problems with the CS SCP for all out going data and should be back up within ~5 minutes. AT 17:29 the DSN OPS CHIEF called and stated that they were having problems with the LAN out at JPL, no ETA at to when it would be fixed. At 17:36 telemetry came back online. Telemetry was offline from 17:06 to 17:36. IMPACT: None. All data was subsequently recovered. DR# G102830 Day 03156 (06/05/2003) ACE Anomaly Report #S03-0010 - Wrong EPAM Command FOT was contacted by David Lohr, EPAM Instrumenter, to perform OCR EPAM-002. Command "EPAM_DATA CMD_DATA=h'6200' " was sent to the Spacecraft and was verified on the Spacecraft. After ~2-5 minutes, David Lohr notified us that he did not see the expected result. After further investigation by the EPAM instrumenters, it was determined that first command had the incorrect hex value. The instrumenters then submitted a second OCR to send the correct command. However, that command did not have the expected result either. The FOT launched their own investigation and recalled that the EPAM instrumenters had performed this same activity back in 1998. Investigation revealed that the same command as listed above was sent then and did not achieve the desired result. The FOT looked at the command build and found that the ground software was adding an additional parity bit which resulted in a NO-OP command being sent. The FOT notified the instrumenter of its findings and what the correct command should be. The instrumenter has concurred and the correct command is expected to be sent Monday 6/9/2003 (DOY 160). ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~