ACE Weekly 07/25/03 - 07/31/03 All ACE spacecraft subsystems are performing nominally. An attitude maneuver was successfully executed on 07/25/03. The next attitude maneuver is scheduled for 08/07/03. ============================================================================ 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: 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. Testing is progressing on both TAPS#1 and TAPS#2. The next release (4.1.6) is projected to occur on 08/05/03. ---------------------------------------------------------------------------- Automation (ROBOTT): FOT testing of ROBOTT Release 0.1 is ongoing. CRON testing on String 2 is progressing, although some minor problems have occurred. Command & Control (C&C) ES still in development phase. Testing results and corrections still need to be made. Expected development testing by the Automation Team to resume at the end of August. The next release of Offline should be ready for the FOT to test on String 3 by the end of next week. ============================================================================ Anomalies: DOY 03206 (7/25/2003) - ACE Anomaly G03-0063 - GDS 26m (DSS-24) TLP Swap / Telemetry Outage At 15:57:52, telemetry dropped out from DSS-24. DSS-24 switched from TLP-5 to TLP-2 and telemetry was back online at 16:08:46. IMPACT: Delayed maneuver activities. Maneuver executed nominally and all telemetry was acquired. DR# G103077 DOY 03207 (7/26/2003) - ACE Anomaly G03-0064 - GDS 26m (DSS-16) Command Verification Not Received From S/C At 15:44, during G_INITIAL_CONTACT, the Bin_Clear command was not verified by the S/C. After 3 attempts at transmitting the command, DSS-16 was notified. The station confirmed receipt of the command and said it was radiated. At 15:47, with DSS-16 monitoring their system, commanding was resumed and again the command didn't get to the S/C. The FOT requested DSS-16's command mod index - DSS-16 stated it was 0.86. DSS-16 then reset the command mod index and at 15:52 commanding was resumed. Verification was finally received from the S/C. IMPACT: Delay in commanding from 15:44 to 15:52. DR# G103084 DOY 03207 (7/26/2003) - ACE Anomaly S03-0014 Limit Violation - SSCPAM5V Red High Limit Violation At 17:44:15 SSCPAM5V violated the red high limit of -4.5V, at a value of -4.373. It returned within limits at 17:45:16. Notified Jim Raines. IMPACT: Unknown at this time. FOT will continue to monitor. DOY 03207 (7/26/2003) - ACE Anomaly S03-0015 Limit Violation - SSCGR20V Yellow Low Limit Violation At 17:08:46 SSCGR20V violated the red low limit of 17V, at a value of 16.1. It returned within limits at 18:09:10. Notified Jim Raines. IMPACT: Unknown at this time. FOT will continue to monitor. DOY 03210 (7/29/2003) - ACE Anomaly G03-0067 - GDS 26m (DSS-16) TCP and Frame Synch Problems The FOT informed DSS-16 during the prepass briefing that the S/C would be coming up in 498 bit rate. When DSS-16 put telemetry online at the 498 bit rate the FOT noticed the SFDU header bit rate read 87648 bps vice 498 bps. At 12:39:12 telemetry went offline due to reported TCP problems. Telemetry was back online at 12:50:24. IMPACT: Clock calibration file will be wrong. DR# G103101, G103102 DOY 03212 (7/31/2003) - ACE Anomaly G03-0068 - SIMSS Runtime Halt SIMSS stopped running and generated a "runtime halt" dialog box. The DSN Monitor Client window was continuously displaying the following line: Socket Exception: Connection reset by peer: JVM_recv in socket input stream read. IMPACT: SIMMS didn't capture the 0158 data from the beginning of the support ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~