ACE Weekly 05/19/2010 - 05/25/2010 All ACE spacecraft subsystems are performing nominally. ======================================================================== Orbit/Attitude: Type Attitude Date 05/21/2010 DOY 141 2010 Thrusters 2R 4R+ 4R- Duration 14:06 min Start 13:54:04z Stop 14:08:10z HGAStart -7.98deg HGAStop 8.07deg SunStart 12.26deg SunStop 5.69deg SpinStart 5.0627rpm SpinStop 5.0666rpm Nutation 0.12deg Firing 72 pulses FuelUsed 0.2271lbs FuelRemain 136.3328lbs FinalSCMass 1370.593lbs The next attitude maneuver is scheduled for Tuesday 06/01/2010. ======================================================================= OCRs: None ======================================================================== Activities: Data Capture: 100% DOY 136-143 2010 At the end of April (DOY 116 04/26/2010 23:45:00z), the SEPICA line pressure (SSSLINEP) started fluctuating. There are no limits for SSSLINEP. SSSLINEP data has been sent to Mark Popecki (SEPICA instrumenter) for review. ======================================================================== Anomalies: DOY 139 05/19/2010 S-ACE-0505 G10-0026 ITOS tm_controller ITOS was unable to process telemetry due to a "timeout reading from tm_controller". ITOS was restarted before beginning of track. This problem occurs approximately once every 2 weeks. DR CDSID#00027515 has been submitted and the ITOS developers expect this to be fixed in ITOS 805. IMPACT: Manual intervention required. No delay in activities. DOY 139 05/19/2010 S-ACE-0506 S10-0004 S3DPU_CONV_SEC_I RH Limit S3DPU_CONV_SEC_I had a brief red high limit violation (RH > 480 mV). 2010-139 16:28:25 - 16:28:26 482.406-490.25 mV Mark Popecki was notified. IMPACT: The last brief S3DPU_CONV_SEC_I red high limit violation was DOY 319 2006. DOY 145 05/25/2010 S-ACE-0507 G10-0027 MUS CMD process terminated The MMOC SLE (MUS) cmd process (ace-d45-cmd) terminated unexpectedly 2 minutes after beginning of track. MUS did not generate an error message. The Ops Chief notified the FOT that no commands had reached the station at 27 minutes after beginning of track. The MUS CMD process was restarted at 35 minutes after beginning of track. Note: The MUS cmd process dies on average once every 3 weeks, but usually in conjunction with other problems. It is rare that the MUS cmd process dies on its own. IMPACT: Manual intervention required. Activities delayed 35 minutes. DOY 145 05/25/2010 S-ACE-0508 S10-0005 FAILCMDTFRM_CT increment ITOS has a known issue (CDSID# 00027467) where an "OPEN port" directive causes an ITOS proc to go through a WAIT. After restarting MUS CMD with an OPEN port (see AR#G10-0027), the ITOS proc was manually resumed. However, the proc did not remain at the wait for command verification. The 2nd and 3rd commands were sent before the 1st command. The spacecraft flagged the out-of-sequence commands. ITOS then retransmitted all 3 unverified commands in the proper order. IMPACT: Minimal. The spacecraft flagged and discarded the out-of-sequence commands. ITOS automatically retransmitted the commands. The last command sequence error was DOY 295 2007 (AR#G07-0092) due to a dropped command by the ground network.