ACE Weekly 11/12/2008 - 11/18/2008 All ACE spacecraft subsystems are performing nominally. ============================================================================ Orbit/Attitude: Type Attitude Date 11/14/2008 DOY 319 2008 Thrusters 2R 4R+ 4R- Duration 11:30 min Start 15:11:55z Stop 15:23:25z HGAStart -7.11deg HGAStop 7.33deg SunStart 16.26deg SunStop 6.04deg Nutation 0.38deg Firing 58 pulses FuelUsed 0.1925lbs FuelRemain 146.7472lbs FinalSCMass 1381.007lbs The next attitude maneuver is scheduled for Monday 11/24/2008. =========================================================================== OCRs: DOY 318 (11/13/2008) 1605-1725z SEP-110 Step 1-3 SEPICA power cycled to recover from Standby Mode (DOY 316, AR#S08-0004). Activities were continued on DOY 323. DOY 323 (11/18/2008) 1649-1758z SEP-110 Steps 3-7 SEPICA voltage ramp-ups and restoring configuration completed. DOY 323 (11/18/2008) 1814 - 1817z SEP-111 SEPICA baseline subtraction for event processing was reinstated. This is helpful for weak signals. Baseline subtraction was disabled when internal stimulation was disabled during OCR SEP-110. The SEPICA instrument is back to operating as before. ============================================================================ Activities: Data Capture: 100% DOY 314-321 2008 There is a higher than normal risk of data loss from October 2008 through February 2009. If there are problems with the passes, it may not be possible to acquire additional DSN time. This higher-risk period has been occurring every winter for the past couple of years. For more information refer to 10/14/2008 weekly. ============================================================================ Anomalies: DOY 316 11/11/2008 S-ACE-0379 S08-0004 SEPICA Switched to Standby Mode The SEPICA instrument switched to Standby Mode between 18:03:43 and 18:03:55z on DOY 316. Mark Popecki has not found any obvious reasons for the switch to Standby in the telemetry; many SEPICA housekeeping parameters are only available once each minute. The last time SEPICA unexpectedly switched was DOY 148 2001 (05/27/2001). The 2001 Standby was most likely caused by a limit violation on the -15v supply. IMPACT: SEPICA was successfully power cycled on DOY 318. Voltage ramp-ups and restoring configuration were completed on DOY 323. DOY 318 11/13/2008 S-ACE-0380 G08-0114 ROBOTT/C&C Start 2 Procs ROBOTT/C&C started 2 procedures without waiting for the other to complete; S_OPS_PLBK_COMPLETE (17:27:43) and G_END_DAY (17:30:36). The procedure S_OPS_PLBK_COMPLETE was paused while G_END_DAY completed. ROBOTT/C&C then froze. CDSID#21085 & #21122 IMPACT: These are recurring issues that the ROBOTT developers are aware of. No further commanding was needed during the pass.