ACE Weekly 08/26/2009 - 09/01/2009 All ACE spacecraft subsystems are performing nominally. ======================================================================== Orbit/Attitude: No maneuvers were completed this week. The next attitude maneuver is scheduled for Friday 09/04/2009. Station-Keeping #52 is scheduled for Thursday 09/24/2009 ======================================================================= OCRs: None ======================================================================== Activities: Data Capture: 99.99% DOY 235-242 2009 31 second gap during SSR failover (DOY 240 2009 06:20:51-06:21:21) 31 second gap during SSR failover (DOY 244 2009 14:08:16-14:08:47) The LCROSS mission declared a spacecraft emergency on Saturday 08/22/2009 (DOY 234). ACE has given up passes on DOY 239 and DOY 243 resulting in brief 31-second gaps during the SSR failover. Further passes may be lost. (Note, the DOY 244 gap actually falls in next week's reporting period.) Background Information: ACE utilizes 6 DSN antennas (24,27,34,45,54,65). DSS-54 has been unavailable since July 1 due to the KA-Band Phase 2 upgrade. DSS-54 is expected to return to service on October 5. DSS-24 is unavailable for the month of September. ACE ground automation gives some flexibility in moving passes and this has been the major factor in avoiding major data loss in the past week. There are 2 minor disadvantages to the ACE ground automation system that should be mentioned: 1) Problems with commanding will result in a lost pass (e.g. the JPL router problem on DOY 211) 2) Unable to use DSN stations with only S-Band downlink. Over the years DSN problems have become more infrequent and there is only one DSN station that has S-Band downlink but no S-Band uplink (DSS-15). Therefore, on the whole, ACE ground automation fits well for ACE's needs. A Multi-Mission Operations Center (MMOC) test will be performed on Thursday 09/10/2009 (DOY 254 0020-0100z). The spacecraft will be commanded to hi-rate and data from the previous pass will be redumped. All data will have been captured by the legacy system. ======================================================================== Anomalies: None