ACE Weekly 09/02/2009 - 09/08/2009 All ACE spacecraft subsystems are performing nominally. ======================================================================== Orbit/Attitude: Type Attitude Date 09/04/2009 DOY 247 2009 Thrusters 2R 4R+ 4R- Duration 14:47 min Start 15:01:26z Stop 15:16:13z HGAStart -6.98deg HGAStop 7.51deg SunStart 5.68deg SunStop 11.71deg SpinStart 5.0312rpm SpinStop 5.0352rpm Nutation 0.20deg Firing 75 pulses FuelUsed 0.2387lbs FuelRemain 140.9796lbs FinalSCMass 1375.240lbs The next attitude maneuver and Station-Keeping #52 are scheduled for Thursday 09/24/2009 ======================================================================= OCRs: None ======================================================================== Activities: Data Capture: 99.99% DOY 242-249 2009 31 second gap during SSR failover (DOY 244 2009 14:08:16-14:08:47) The LCROSS mission is no longer declaring spacecraft emergency, but has increased their DSN usage. DSS-24 and DSS-54 continue to be unavailable. For most of the passes in the upcoming week, SSR playback will not be finished until the following pass. If there are no problems with the passes, all data will be captured. A DSS-54 Return To Service test will be performed on Wednesday 09/09/2009. A Multi-Mission Operations Center (MMOC) test will be performed on Thursday 09/10/2009 (DOY 254 0020-0100z). The spacecraft will be commanded to hi-rate and data from the previous pass will be redumped. All data will have been captured by the legacy system. ======================================================================== Anomalies: DOY 245 09/02/2009 S-ACE-0458 G09-0051 TPOCC Procedure Problems The SSR redump procedure (s_ops_plbk_complete) did not start and the final state of health check procedure did not complete (g_end_day). For g_end_day, the BinDump command was sent and the spacecraft switched to BinDump format. TPOCC, however, remained at the line in WAIT UNTIL (P@DNLK_FORMAT_ID = "BIN_DUMP"). For s_ops_plbk_complete, the automation software checks TPOCC for the SSR status. When the SSR playback completed, the automation software did not see the change in SSR status in TPOCC. Impact: The pass completed without further commanding. No redumps were needed and the spacecraft downlink format returned to RTSW at the end of the pass. Typically, TPOCC has problems when a hardware failure is imminent or when a process is using excessive cpu/memory. There have been no problems with subsequent passes. DOY 248 09/05/2009 S-ACE-0459 S09-0005 Increase in SBE_CT_B SSR B Single Bit Error Count (SBE_CT_B) increased from 5067 to 5646 since last checked on DOY 238 (08/26/2009). SBE_CT is tracked as a measure of SSR health. IMPACT: Minimal. Single Bit Errors are automatically corrected by the SSR and occur infrequently. No non-correctable errors (Hard Single Bit Errors & Double Bit Errors) have occurred throughout the mission. SBE_CT_A SBE_CT_B 12/01/1999 15 09/06/2003 286 02/25/2003 30 09/22/2004 608 06/05/2003 270 11/15/2004 858 07/26/2007 510 11/07/2006 2118 03/18/2009 525 01/12/2007 3125 06/21/2007 3238 04/26/2008 3999 05/10/2008 4533 (slice 253) 07/31/2009 4697 08/02/2009 5067 (slice 253) 09/05/2009 5646