ACE Weekly 08/08/03 - 08/14/03 All ACE spacecraft subsystems are performing nominally. No maneuvers were executed this week. The next attitude maneuver is scheduled for 08/18/03. ============================================================================ Orbit Events: The next SEV transit will occur during the 09/01/03 - 09/23/03 time frame. Expected minimum SEV angle will be 1.76 degrees. The essential timeline based on a 30-min step scan for this 22 day, 8.5 hour event is: - SEZ entry (4.75 deg inbound) on Sept. 1 at 0100Z - Minimum Sun-Earth-ACE angle = 1.760 deg on Sept. 12 at 0800Z - SEZ exit (4.75 deg outbound) on Sept. 23 at 0930Z ===================================================================== OCRs Executed: Day 03226 (08/14/03) - OCR# SC_03_001 - Blind Commanding of SSR Dump DSN problems for two consecutive days has raised the possibility for data loss. CDR file from yesterday's support showed good data capture by DSN. While DSN time is available late today, there still may be possible data loss. Starting the dump (& verifying it via CDR replay) will possibly minimize data loss and the amount of DSN time needed later. ===================================================================== Ongoing Activities: TAPS: Trending, Analysis and Plotting System (TAPS) development continues with emphasis being placed on fixing the DRs attributed to prior releases. Release 4.1.6 was installed successfully on 08/05/03 and is currently in test by FOT. ---------------------------------------------------------------------------- Automation (ROBOTT): - ROBOTT Release 0.2 was installed on String 2 on 08/13/03. Since the install, the FOT has been testing at the individual button level with one minor environment problem. - HSM testing continues on String 3. - No progress on Command & Control, delivery date to FOT is still TBD. ===================================================================== Anomalies: DOY 03224 (08/12/2003) - ACE Anomaly G03-0074 - GDS 26m (DSS-16) Command Not Getting to Spacecraft The first command sent didn't reach spacecraft; DSS-16 said the command was leaving the station however the FOT saw no indication on board the SC that the command had been received. DSS-16 rebooted TCP1. FOT referenced AR G03-0064 and suggested to station to reset the command mod index. DSS-16 manually reset the command mod index to the wrong values. Further attempts to command were only partially successful. DSS-16 configured the command mod index to the correct value and commanding resumed with no further problems. IMPACT: Delayed pass activities 40 minutes. DR G103183 DOY 03224 (08/12/2003) ACE Anomaly G03-0075 - GDS 26m (DSS-16) TCP Halt At 15:06:59 telemetry went offline. DSS-16 informed FOT that TCP1 halted and needed a reboot. After the reboot the telemetry came back online. IMPACT: None. All data was acquired. DR# G103184 DOY 03225 (08/13/2003) ACE Anomaly G03-0077 - GDS 26m (DSS-16) Reliable Network Server (RNS) Problems FOT gave prepass briefing to station; DSS-16 informed FOT that they were having RNS problems (Goldstone Complex Wide) with No ETA on when the RNS would be fixed. Telemetry dropouts occurred throughout pass. Commanding problems as well with continued drops in telemetry. Problems with RNS continued on DSS-27 on DOY 03226. IMPACT: Unable to dump recorders, however the data was retrieved at a later date. Because of this problem with the RNS and the inability to confirm command receipt via telemetry, a reconfiguration of the SC RF subsystem would occur and will be documented at a later date (see AR S03-0017). DR#s G103191, G103203 DOY 03226 (08/14/2003) ACE Anomaly S03-0017 - RF Watchdog Timer Expired AT 16:09:27 XPNDR B-RF Watchdog triggered which caused the XPNDR B to reconfigure to the broadbeam antennas on the top deck and enabled the XPNDR_HTR relay. Antennas successfully reconfigured on DOY 03227 at 22:00:05. IMPACT: Additional contacts required to reconfigure antennas to nominal configuration. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~