ACE Weekly 10/07/05 - 10/13/05 All ACE spacecraft subsystems are performing nominally. ============================================================================ Orbit/Attitude: Type Attitude Attitude Date 10/11/05 10/11/05 DOY 284 2005 284 2005 Thrusters 2R 4R+ 4R- 2R 4R+ 4R- Duration 7:43 min 6:46 min Start Time 16:57:03z 17:59:14z Stop Time 17:04:46z 18:06:00z Firing 39 pulses 35 pulses The next attitude maneuver is scheduled for Friday 10/28/05. ============================================================================ OCRs: DOY 280 (10/07/05) 1615-1624z SWPX-041 SWEPAM-E overcount protection function adjusted to help extend the instrument's operational life. Overcount threshold changed from 128 to 32 and CemHV_SafeDataMode increased from 15 to 255 cycles. DOY 286 (10/13/05) 1639-1648z and 1732-1744z SIS-031 Leakage currents on HV side of Matrix detector M1B have been steadily rising, resulting in more and more detector strips having to be manually turned off. By reducing the M12B bias voltage from 2.8 to 2.3V we hope to reduce the overall leakage current problem on this detector. After ~1 hour, the instrument team decided to restore the bias voltage back to 2.8V. ============================================================================ Ongoing Activities: Space Link Extension (SLE) - ACE SLE development continues but may be put on hold as developer resources are diverted to SOHO SLE and other projects. RIONet - String 3 is anticipated to move to the RIonet within a month. ============================================================================ Extra Activities: None ============================================================================ Anomalies: DOY 280 (10/07/05) S05-0046 SWICS Red High Limit Violation SSCPAM5V had 4 brief red high limit violations (RH >-4.5V). Jim Raines notified. 2005-280 22:18:36 - 22:19:00 -4.412 - -4.490V 2005-280 23:30:40 - 23:31:04 -4.373 - -4.412V 2005-281 00:30:31 - 00:30:55 -4.451 - -4.490V 2005-281 04:39:56 - 04:40:20 -4.490V IMPACT: Awaiting instructions from Jim Raines. DOY 286 (10/13/05) G05-0127 AC3FE1A Frozen AC3FE1A workstation frozen and unable to remotely login. System Administrator was able to reset the workstation. IMPACT: Minimal, workstation on backup string. DOY 286 (10/13/05) G05-0128 GDS DSS-16 Uplink Lost Commercial power glitch at station (18:15:34z) resulted in a brief TLM outage and a loss of the uplink. Station successfully reacquired uplink (18:24:47z) DR# G106166 IMPACT: Minimal. ROBOTT did not perform the second check of ULSRB_MOT_ERR. ULSRB_MOT_ERR has not flagged since DOY 256. DOY 286 (10/13/05) S05-0047 Incorrect SIS CMD ECHO While executing OCR SIS-031, the SIS CMD ECHO (to restore the bias voltage to 2.8V) did not match the command sent: 17:32:36 CMD: /cmd sis_vstring statement=6~SDACVAL~13~+~C!~REFON 17:33:12 ECHO: 6 SDACVAL 13 + C! REN REN?~| Instrumenter requested an additional command 17:35:46 CMD: /CMD SIS_REFON 17:36:21 ECHO: REFON Ok~| After the pass, the hex sequence and the command echo from the station were verified. The command transmitted and received by the spacecraft was correct. IMPACT: No impact mentioned by instrumenter.