ACE Weekly 03/05/2008 - 03/11/2008 All ACE spacecraft subsystems are performing nominally. ============================================================================ Orbit/Attitude: Type Attitude Attitude Date 03/06/2008 03/06/2008 DOY 066 2008 066 2008 Thrusters 2R 4R+ 4R- 2R 4R+ 4R- Duration 3:59 min 10:26 min Start 16:37:44z 18:00:56z Stop 16:41:43z 18:11:22z HGAStart -6.65deg -3.20deg HGAStop -3.20deg +7.80deg SunStart 4.34deg 5.99deg SunStop 5.99deg 16.39deg Nutation 0.31deg 0.16deg Firing 21 pulses 53 pulses FuelUsed 0.0752lbs 0.1749lbs FuelRemain 151.2384lbs 151.0636lbs FinalSCMass 1385.498lbs 1385.324lbs The next attitude maneuver is scheduled for Wednesday 03/26/2008. =========================================================================== OCRs: None ============================================================================ Activities: In the transition to SLE, the ACE MOC stopped sending the precal test command to the DSN station (11/30/2007). The DSN stations have requested that the precal test command be reinstated. This will be done starting Thursday 03/13/2008 (DOY 073 2008). ============================================================================ Anomalies: DOY 066 03/06/2008 S-ACE-0286 G08-0026 ROBOTT Restart For unknown reasons, the ROBOTT automation software failed to start. The Real-Time Monitor successfully caught the problem and started the software at BOT-1hour. IMPACT: Minimal. No manual intervention required. DOY 066 03/06/2008 S-ACE-0287 G08-0027 Duplicate Data Received On several occasions, 50-100 duplicate frames have been received in the MOC. For most of these days, the CDR file also has a large number of blocks with null bytes at the end of the CDR file. DOY 063 DSS-27 21:38:37 DOY 065 DSS-27 22:17:01 - 22:17:04 DOY 066 DSS-24 17:01:45 - 17:01:47 DOY 067 DSS-27 16:38:11 - 16:38:16 DOY 068 DSS-66 15:55:06 - 15:55:09 IMPACT: Minimal. Aside from the blocks of null bytes, the data on the CDR appears to be OK. DOY 067 03/07/2008 S-ACE-0287 G08-0028 Pass Lost & Voice Loop Down TDRS-9 declared a spacecraft emergency and the pass with DSS-66 was rescheduled for DSS-27. The FOT was unable to contact the DSN Ops Chief over the Voice Loop due to a JPL Voice Switch Failure on DOY 066. The FOT contacted the Ops Chief via the commercial phone line. IMPACT: Minimal. DOY 069 03/09/2008 S-ACE-0288 G08-0029 DSS-24 Unable to Lock on TLM At Beginning Of Track (BOT), DSS-24 was unable to lock on telemetry after applying the uplink. A second Downlink Channel Controller (DCC) was also unable to lock onto telemetry. The station also tried to configure for high-rate telemetry, however, the spacecraft remained at low-rate. The station resolved the issues by BOT+23 minutes. DR#G108411 IMPACT: Activities delayed 23 minutes. DOY 069 03/09/2008 S-ACE-0288 G08-0029 DSS-46 SLE Configuration DSS-46 was not transmitting commands received via SLE. The station reloaded the SLE Service Instance Configuration File and the commands were successful. DSS-46 recommended reinstating the precal test command to help indicate possible problems during precal. DR#C106241 IMPACT: Activities delayed 12 minutes.