ACE Weekly 09/30/2015 - 10/07/2015 All ACE spacecraft subsystems are performing as expected. ======================================================================== Attitude/Orbit: Type Attitude Date 10/07/2015 DOY 280 2015 Thrusters 2R 4R+ 4R- Duration 10:22 minutes Start 18:34:00z Stop 18:44:22z ra,decStart 189.46,-19.58 ra,decStop 199.54,-21.83 ra,decExpect 199.84,-22.09 Deviation 0.33 deg (-3.3%) HGAStart -10.48 deg HGAStop 10.05 deg SunStart 14.51 deg SunStop 17.60 deg SpinStart 5.0347 rpm SpinStop 5.0375 rpm Nutation 0.13 deg Firing 53 pulses FuelUsed 0.1634 lbm FuelRemain 95.3704 lbm FinalSCMass 1329.631 lbm Maneuver Scheduling: Next attitude maneuver: Wednesday, 10/14/2015 Next station keeping maneuver: Wednesday, 10/14/2015 ======================================================================== OCRs: Reminder/Update on ACE-355: Relaxing the ACE antenna constraint from 9 to 11 degrees for the 2015 Summer Campaign. The 2015 Summer Campaign, which started on 5/19/2015, will conclude with the 10/20/2015 attitude maneuver. The return to the 9 degree upper limit antenna constraint will allow ACE to resume operations with WS1. ======================================================================== Activities: Data Capture: 99.9717% DOY 270-277 2015 Notes: The DOY 274 DSS-34 pass was lost (see anomaly section below), and SSR fail-overs were performed on DOY 275 (at 275-10:14:23.3 UTC) and DOY 277 (at 275-05:12:02.06 UTC). The SSR failover transitions are responsible for 63 seconds of data loss. An additional 128-sec data gap was identified for (VC4) playback data during the 276-17:14:39 (UT) - 276-17:16:46 (UT) time window. Inspection of the DOY 276 event log and the DSN DR system does not yield any ground system problems which correlates with the 128 sec data gap. Per standard procedure, the FOT will investigate further and retrieve the corresponding IDR data, to confirm if there are any differences from the MOC-acquired SLE data. ======================================================================== Anomalies: -SOAR S-ACE-37 - Pass loss due to hardware issue at DSS-34 (DR #C111407). The Ops chief informed the FOT prior to the DSS-34 contact that the DSS-34 transmitter was declared RED and the pass would be lost. Impact: Minimal. The FOT assessed the impact of the SSR data management (downstream the schedule) identified contact scheduling changes to avoid data losses (i.e., converting some ranging-only passes to tracking) and worked with the SSMO Scheduling Team to implement the changes. There are only 63 seconds of expected data losses due to the SSR failover transitions, as described above. Barring some additional ground system problems, the FOT expects to be fully caught-up by DOY 283 (Saturday, Oct-10).