ACE Weekly 03/07/03 - 03/13/03 All ACE spacecraft subsystems are performing nominally. Attitude maneuvers were performed on 03/07/03 and 03/12/03 successfully. The next attitude maneuver is scheduled for 03/21/03. ============================================================================ Orbit Event: SEV Transit On 03/06/03, at 1754Z, ACE began a Solar Exclusion Zone (SEV) transit that will conclude on 03/20/03 at 1518Z. The minimum SEZ angle of 2.68 degrees will occur on 03/15/03 at 2326Z. NOTE: Be advised that telemetry dropouts may occur during this time period. The next expected SEV transit is to occur: 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: NONE ============================================================================ Ongoing Activities: TAPS: Trending, Analysis and Plotting System (TAPS) development continues with emphasis being placed on fixing the DRs attributed to the current release. TAPS Patch 4.1.1 was installed on TAPS #2 on 02/27/03. Testing is progressing on TAPS#2. TAPS#1 is no longer required for development and will be under CM control after the system has been wiped by the TSMs. TAPS 4.1.1 will be installed on TAPS#1 and released for testing. ---------------------------------------------------------------------------- Automation (ROBOTT): Moving of the Offline subsystem has been delayed pending approval of updated offline activities and testing of those activities. The release of the Command & Control subsystem has been delayed until completion of WIND/POLAR automation task, new release date is TBD. HSM is currently being tested by the FOT on string 3. HSM has been working well except for a few random problems that need to be addressed. It will go through several iterations before being moved to string 2. Once any piece of the ROBOTT software is moved to string 2, it will referred to as an 'engineering' version and any problems will be documented via CDS. ============================================================================ Anomalies: DOY 03068 (3/9/2003) - ACE Anomaly Report G03-0011 - Command not received by Spacecraft At 13:33, the FOT started the procedure C_SCIENCE. At 13:34:56, the procedure was still waiting verification. A check of the FOT command count indicated that 11 commands had been sent (10 cmd blks/1 test blk), and only 10 echos rec'd. At 13:37, the FOT contacted D54 to inquire about the command. D54 informed the FOT that a total of 10 commands (9 cmd blks/1 test blk) had been rec'd. At 13:39, the FOT informed IP NOCC of the situation. IP NOCC had a command count of 11. At the FOT's request, IP NOCC set their displays to monitor the next command from ACE. At 13:52, the FOT informed JPL. JPL stated they were unable to check for previous commands, however, they would stand-by to monitor the next real-time command. At 14:06, the procedure, C_SCIENCE was terminated(kp-kill procedure) and a /resync was performed in order to sync the ground and spacecraft command counters. At 14:09, after coordinating the next command with IP NOCC, JPL, and D54, the procedure C_SCIENCE was started again and verification was received. All parties involved confirmed receiving the command. After the pass a command delog was performed, however, there were no problems noticed with the command. IMPACT: Minimal. Delayed the execution of C_SCIENCE and ULEIS_MOTOR_ERROR procedures. DOY 03071 (3/12/2003) - ACE Anomaly Report G03-0012 - SEZ - Data loss at 87648bps Initial evidence indicates that we have reached the SEV angle (3.03deg) where 26m antennas are unable to maintain data at the high date rate. ~20% data loss at 15:00:00 ~75% data loss at 17:30:00 Note: At High-Rate, VC1 data also lost. Unable to maintain continuous state of health check. Therefore, SSR dump was not continued (even though it did capture some 6% of VC4 data). ACTIONS: 15:00:00 At hi-rate --- data loss ~20% 15:29:42 Switched to RTSW (498bps) --- No data loss at 498bps 15:42:01 Switched to ADC (7968bps) --- No data loss at 7968bps 17:28:14 Switched back to hi-rate (87648bps) --- data loss ~75%. 17:45:36 Switched back to med-rate (7968bps). No data loss. Continued at Medium-Rate. Scheduled a 2nd pass with D46 to do an attitude maneuver to ensure that HGA constraint would not violate if telemetry were lost before the next scheduled maneuver (originally scheduled for Friday). IMPACT: Unable to complete dump SSR B. DATA LOSS (Preliminary Analysis): Due to the inability to receive hi-rate data with DSS-16 on DOY 071 and the limited time with DSS-27 on DOY 072, the FOT was unable to complete the playback for DOY 070 and 071. However, the FOT was able to focus on data recorded between supports to reduce data loss. Some of the gap is filled with real-time data, of which some is ADC. ADC contains the data for MAG, EPAM, CRIS, SIS and SWEPAM-I, but not SWEPAM-E, SWICS, SWIMS, SEPICA and ULEIS. Totals over DOY 070 and 071: Only ADC 2hr 02min 35sec NO DATA 7hr 39min 42sec The rest of the time captured either Science (vc1 or vc4) or BinDump (vc1). (Note, BinDump contains all instrument data.) Here are the time ranges: 070 15:14:20 - 15:31:13 only adc 16min 54sec 070 17:52:18 - 18:15:09 only adc 22min 52sec 070 18:15:10 - 18:17:57 no data 2min 48sec 071 08:07:58 - 14:56:37 no data 6hr 48min 40sec 071 14:56:38 - 15:30:06 some adc 17% captured (5min 20sec data/28min 09sec lost) 071 15:30:07 - 15:43:23 no data/rtsw 13min 17sec 071 15:43:24 - 15:59:59 only adc 16min 36sec 071 16:00:00 - 16:06:47 no data/rtsw 6min 48sec 071 16:06:48 - 17:27:40 only adc 1hr 20min 53sec Able to maintain hi-rate data on Days 072 through 075 using D27, D24 & D54 (all 34m antennas). DOY 03071 (3/12/2003) - ACE Anomaly Report G03-0013 - DSN GDS(DSS-16) - Antenna Track Stop At 17:08:37 lost uplink. Queried station DSS-16 as to the cause of the loss and DSS-16 reported the antenna had stopped tracking. CAUSE: While performing E-Stop PMs on DSS 15's antenna, the operator pressed the wrong E-Stop button causing the DSS 16 antenna to go to brake. Corrective Action: The Axis Hydraulics were enabled, the transmitter beam was brought back up for ACE support and the track directive was entered. (Personnel Error) IMPACT: Telemetry loss between 17:12:15 and 17:15:45 DR# M101446. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Glen A. Miller Honeywell Technology Solutions Inc. ACE Flight Operations Team 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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~