ACE Weekly 05/14/04 - 05/20/04 All ACE spacecraft subsystems are performing nominally. No attitude maneuvers were executed this reporting period. The next maneuver (attitude & stationkeeping) is scheduled for 05/27/04. ============================================================================ 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: 05/14/04 - SWM-032 - Adjust SWIMS MCP voltages, in hopes of tracking down a high background condition that has been present since the recent HV restore. ===================================================================== Ongoing Activities: TAPS: - Transition from GTAS to TAPS occurred on 03/18/04. All trending activities are being accomplished using TAPS. - Installation of TAPS release 4.3 is tentatively scheduled for the first week of July 2004. All open DRs will be fixed in this release. - An additional DR has been opened. The FOT found that TAPS drops 3 frames per every 152 frames processed for product generation. ---------------------------------------------------------------------------- Automation (ROBOTT): - Release 0.6 installed on String 1 on 05/13/04. Operations has moved to String 2 and will remain there until FOT testing on String 1 is completed. - 14 DRs have been verified out of 25 reported fixed in this release. - 4 DRs have been opened as a result of FOT testing of Release 0.6. -- 19 DRs are OPEN to date. - SUG development is ongoing. A DRAFT version has been delivered and is still being reviewed by the FOT. Comments will be provided to the developer. - FOT training on ROBOTT began 05/05/04 and additional sessions are being developed. ============================================================================ Extra Spacecraft Activities: SWIMS instrument commanding under direction from Jim Raines (Univ. of Michigan). ===================================================================== Anomalies: DOY 04135 (05/14/04) ACE Anomaly G04-0038 - TPOCC Displays Crashed When trying to create a plot of SFDU_SEC_SYNC_ERR (a system variable extracted from the DSN telemetry header) from the page ENIF_TLMHDRS_1, incorrectly clicked "Edit XtpNumeric..." This caused the TSTOL and STDHDR windows to close. IMPACT: The vc2seqerr.rpt file was also closed. It had recorded the VC2 sequence errors up to 15:35:26, but did not record the sequence errors after 15:35:26. Automatic redumps could have been done, but instead all of the redumps were done manually. DOY 04134 (05/13/04) ACE Anomaly G04-0039 - TAPS Skipping Data TAPS is skipping 3 out of every 152 frames. If TAPS is reading 32768 (32kB) each time, then that corresponds to 37.75 frames ( 37.75 = 32768 / 868 ). TAPS isn't correctly processing the frame that's split between reads. IMPACT: Erroneous Limit Violations can be triggered and daily and long term trending products may contain erroneous data. DOY 04140 (05/19/04) ACE Anomaly G04-0040 - MAD 26m (DSS-66) Late AOS / Incorrect Cmd Modulation Index DSS-66 was unable to provide telemetry at the expected AOS time of 11:40:00. The station reported having problems on their end. At 11:50:43, the FOT received telemetry from DSS-66. The FOT received the go for command and proceeded with the daily commanding. However, RCVR_A/B_AGC levels dropped every time a command was sent. The FOT checked the DSNMON data and noticed the command modulation index was incorrect. The FOT informed the station and the correct value (1.61 dB/ 0.86 radians) was entered. IMPACT: Late AOS, delayed pass activities. All data was subsequently recovered from the recorders. DR# M102490 DOY 04141 (05/20/04) ACE Anomaly G04-0041 - Packet Extractor Timeout Detected At 13:35:28 (AOS), the FOT received the following event message; "Packet extractor lost connection with packet client TlmLZP." The FOT checked the DPS Main menu advisories and noticed the following message; "PE timeout detected: Reading pkt from PE data dropout detected session capture will continue." Message ID: 1018 Session ID: 4605 IMPACT: None. All data was processed by DPS. This anomaly was written more for information/tracking purposes. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~