ACE Weekly 05/08/2012 - 05/14/2012 All ACE spacecraft subsystems are performing as expected. ======================================================================== Orbit/Attitude: Type Attitude Date 05/14/2012 DOY 135 2012 Thrusters 2R 4R+ 4R- Duration 15:42 min Start 13:22:51z Stop 13:38:33z HGAStart -6.73deg HGAStop +7.82deg SunStart 4.30deg SunStop 10.92deg SpinStart 5.0582rpm SpinStop 5.0634rpm Nutation 0.18deg Firing 80 pulses FuelUsed 0.2434lbs FuelRemain 121.8468lbs FinalSCMass 1356.107lbs The next attitude maneuver and Station-Keeping #61 are scheduled for Friday 05/25/2012. The sun angle drifted below the 4 degree sun constraint from Monday 5/7/2012 (128-23:45:32) to Monday 5/14/2012 (135:05:24:28), reaching 2.8 degrees on Thursday 5/10/2012. There was no impact to the sun pulse generation. The reason for drifting through the sun constraint was to improve the antenna pointing towards earth during the SEZ transit and to increase the time between maneuvers. ======================================================================= OCRs: None ======================================================================== Activities: Data Capture: 99.995% DOY 127-134 2012 DOY 130 17:16:37-17:17:07 31 seconds during SSR failover DSN antenna time on Tuesday 5/8 (DOY 129) and Wednesday 5/9 (DOY 130) was given to the SOHO Mission so that they could recover from multiple Emergency Sun Reacquisition (ESR). ACE data recovery was delayed a couple of days, but eventually all data was captured except for a short 31 second gap during the SSR failover. ======================================================================== Anomalies: DOY 134 05/13/2012 S-ACE-0523 S10-0007 Increase in SBE_CT_B SSR B Single Bit Error Count (SBE_CT_B) increased from 11714 to 12864 between 5/06/2012 and 5/13/2012. SBE_CT is tracked as a measure of SSR health. IMPACT: Minimal. Single Bit Errors are automatically corrected by the SSR. No non-correctable errors (Hard Single Bit Errors & Double Bit Errors) have occurred throughout the mission. SBE_CT_A SBE_CT_B 1999 15 2000 2001 2002 2003 270 286 2004 858 2005 2006 2118 2007 510 3238 2008 4533 2009 525 6839 2010 780 7339 2011 10995 2012 12864 Update on AR#S12-0001 S-ACE-0639 SWEPAM-E Overcount Alarm The SWEPAM-Electron Overcount Alarm flagged on DOY 131 and DOY 135. It had not been flagging since DOY 117. The instrument team is working the next course of action, but their time is limited. IMPACT: The instrument automatically reduces voltages when the overcount alarm occurs.