ACE Weekly 08/20/04 - 08/26/04 All ACE spacecraft subsystems are performing nominally. An attitude/stationkeeping was successfully executed on 08/20/04. The attitude maneuver is scheduled for 08/27/04. ============================================================================ Orbit Events: The ACE stationkeeping maneuver (SK-33) was successfully executed on 08/20/04, coinciding with a scheduled attitude reorientation maneuver. The delta-V was about 0.37 m/sec in the anti-Sunward direction. ACE's Lissajous orbit has now transitioned to an opening pattern, so the ACE motion will now be counterclockwise about L1 (and for that matter, the Sun) for quite a long time to come. ===================================================================== OCRs Executed: None ===================================================================== Ongoing Activities: TAPS: - Installation of TAPS release 4.3 is occurred on 07/20/04. FOT testing of this release is ongoing. -- Of the 6 DRs fixed in release 4.3, 5 have been verified, 1 has failed. - Additional DRs will be submitted for newly found problems. ---------------------------------------------------------------------------- Automation (ROBOTT): - On 08/25/04, ROBOTT v0.8.1 was installed on String 1 (OCR GND-143). -- Operations will be conducted in the "auto" mode with the FOT closely monitoring and noting any discrepancies. - Testing of v0.8.1 by the FOT will continue on String 2. -- To date 24 DRs have been tested successfully and 8 DRs have not been tested. 1 DR has failed and 2 new DRs have been written. ============================================================================ Extra Spacecraft Activities: MOCR 04-1064 G_INITIAL_CONTACT executes C_CONTINGENCY_POKE every day We had been loading this TTBin during the SEZ transits when we thought we might not be able to contact the spacecraft for several days. We had also been letting the TTBin execute to make sure everything was still working (including the calibration of the C&DH B clock). But now we're going to load it every day. We don't ever expect it to execute, since we'll always be reloading it to execute 3 days 23 hours later. We're loading it to reduce the risks associated with lights out operations. This will add 2 real-time commands to our daily activities. +++++++++++++++++++++++++++++++++++++++++++++++++ DOY 04237 - MOCR 04-1071 RF Watchdog Terminal Count set to 80 hours on both C&DH A and B. This is being done to reduce the risks associated with lights out operations. This change will increase the time available to recover from ground problems before the RF reconfiguration on the spacecraft occurs. This is now possible since a time tag bin is being loaded to reset the Last Resort Timer, extending the C&DH reset time to 191 hours (~8 days). ===================================================================== Anomalies: DOYs 04237, 04238, 04239 (08/24-26/04) ACE Anomaly G04-0086 - ROBOTT - C&C Failure During Procedure G_ACEUP With all ROBOTT tasks running the execution of procedures is very sluggish and in some instances results checking occurs before the procedure G_ACEUP completes. If the results checking is not satisfied then C&C kills all procedures (if necessary) and re-executes G_ACEUP. C&C will attempt to run g_aceup 3 times before it requests a reboot. IMPACT: Unnecessary reboots. This shouldn't occur with the installation of ROBOTT v0.8.1. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~