ACE Weekly 05/29/2012 - 06/04/2012 All ACE spacecraft subsystems are performing as expected. ======================================================================== Orbit/Attitude: No maneuvers were completed this week. The next attitude maneuver is scheduled for Thursday 06/07/2012. ======================================================================= OCRs: DOY 152 (05/31/2012) 2212-2219z SWICS-035 Change event prioritization The SWICS instrument team changed the prioritization of events in telemetry to try to get more events needed for science. The Trigger Mode was switched from Energy Only (since 10/25/2011) to Time-Of-Flight (TOF) Only. The basic rate boxes (mass vs mass/charge) were also updated. DOY 154 (06/02/2012) 0107-0110z SWPE-043 Update Overcount Threshold The SWEPAM instrument team doubled the SWEPAM-Electron overcount threshold from 0x20 to 0x40. The overcount alarm had been flagging ~45% of the time for the past 2 months. The overcount alarm was flagging before and after the threshold was increased. The instrument team may make future adjustments after analyzing the data. ======================================================================== Activities: Data Capture: 100% DOY 148-155 2012 The CHANDRA mission was in safe-hold and ACE gave 1.5 hours of antenna time on Wednesday 5/30/2012. The data playback fell further behind after the DSN problems occurred on Friday 6/1/2012. Fortunately, additional antenna time was available on Saturday 6/2/2012 and the data playback is caught up. ======================================================================== Anomalies: DOY 152 05/31/2012 S-ACE-0557 G10-0073 ITOS Disable CMD Failure At the end of the pass, ITOS failed to disable commanding. During the next WIND pass, ITOS was unable to enable commanding for WIND. When ITOS was restarted, it rapidly generated the following event message "graph_process: dbLock(0, 1): dbif_lock.c line 381: semop():". 82000 messages were generated in 36 seconds before the computer was rebooted. This problem is rare. It last occurred operationally on 11/19/2010 and recently during a WS1 test on 4/30/2012. IMPACT: WIND activities on the next pass were delayed 25 minutes. Manual intervention required. DOY 153 06/01/2012 S-ACE-0643 G12-0005 DSN Master Clock Assembly Problems with the Goldstone site Master Clock Assembly (2208z) impacted all of the Goldstone antennas including the ACE pass with DSS-27 starting at 2300z. The MCA was eventually fixed and TLM/CMD established at 0042z. IMPACT: Activities delayed 1hr 42 minutes. No impact to NOAA SWPC since the spacecraft was transmitting at the low data-rate. Additional antenna time was available on the following pass to catch up on the playback.