ACE Weekly 05/21/2014 - 05/27/2014 All ACE spacecraft subsystems are performing as expected. ======================================================================== Orbit/Attitude: Type Attitude Date 05/27/2014 DOY 147 2014 Thrusters 2R 4R+ 4R- Duration 6:46 min Start 14:31:02z Stop 14:37:48z HGAStart -9.50 deg HGAStop +10.83 deg SunStart 15.09 deg SunStop 19.40 deg SpinStart 4.9934 rpm SpinStop 4.9949 rpm Nutation 0.19 deg Firing 34 pulses FuelUsed 0.1110 lbm FuelRemain 106.5068 lbm FinalSCMass 1341.767 lbm The next attitude maneuver is scheduled for 06/03/2014. Update on attitude maneuver performance. Investigation continues into the recent attitude maneuvers being short of the expected target. Attitude maneuvers had typically been off by ~0.25 degrees from the expected target. The maneuvers in May have fallen much shorter of the expected target, although the recent attitude maneuver (5/27) has not been as far off (see following table). Date Actual ra,dec Expected ra,dec Off by (degrees) 04/01/2014 18.95 -5.15 19.18 -5.06 0.25 04/08/2014 27.53 -0.69 27.76 -0.74 0.24 04/15/2014 36.18 2.70 36.37 2.52 0.26 04/22/2014 44.93 5.96 45.12 5.83 0.23 04/29/2014 54.60 12.03 54.87 11.87 0.31 05/06/2014 60.45 26.36 60.85 27.05 0.78 05/13/2014 63.39 32.25 63.78 33.05 0.86 05/20/2014 69.49 35.51 70.20 35.72 0.61 05/27/2014 76.45 37.45 76.99 37.51 0.43 The investigation continues. Future maneuvers are being planned with an extra day of drift. In other words, maneuvers had been planned to allow 8 days of drift, but are now being planned to allow 9 days of drift (with maneuvers on the 7th day). Future weekly reports will note if maneuver performance worsens or a cause is discovered. ======================================================================== OCRs: None ======================================================================== Activities: Data Capture: 100% DOY 138-145 2014 ======================================================================== Anomalies: None