ACE Weekly 03/06/2012 - 03/12/2012 All ACE spacecraft subsystems are performing as expected. ======================================================================== Orbit/Attitude: Type Attitude SK-60 Date 03/12/2012 03/12/2012 DOY 072 2012 072 2012 Thrusters 2R 4R+ 4R- 3A 4A Duration 16:31 min 85.301 sec Start 18:39:33z 20:05:20z Stop 18:56:04z 20:06:46z HGAStart -8.53deg +7.77deg HGAStop +7.77deg +7.78deg SunStart 18.65deg 5.20deg SunStop 5.20deg 5.21deg SpinStart 5.0544rpm 5.0584rpm SpinStop 5.0584rpm 5.0377rpm Nutation 0.11deg 0.10deg Firing 84 pulses Continuous FuelUsed 0.2546lbs 0.2928lbs FuelRemain 123.4660lbs 123.1732lbs FinalSCMass 1357.726lbs 1357.433lbs The next attitude maneuver is scheduled for Wednesday 03/28/2012. The antenna angle before the maneuver was -8.53 degrees. We generally prefer to maneuver before the antenna angle reaches 8 degrees. But in some situations, it is worth exceeding 8 degrees in order to maneuver on the next Monday instead of the previous Friday. MOCR 406 will allow maneuver planning to exceed an antenna angle of 8 degrees with Mission Director approval. The downlink SNR with DSS-27 at -8.53 degrees was +8dB. This is 1 dB more than expected given the expected HGA performance and past DSS-27 performance. ======================================================================= OCRs: DOY 068 (03/08/2012) MOCR 406 >8deg antenna angle with MD approval The current 8 degree antenna angle target is best for most maneuvers. 8 degrees allows most maneuvers to extend to 1 week + 1 weekend. The High Gain Antenna performance drops off significantly between 10 and 11 degrees. An 8 degree target leaves a >2 degree buffer. But there are rare occasions where the antenna angle is expected to reach 8 degrees on Sunday evening. Instead of maneuvering Friday at 6 degrees, the antenna target will be allowed to exceed 8 degrees with Mission Director approval. DOY 072 (03/12/2012) 1915-1918z CRIS-011 The Image Intensifier was powered on after being automatically safeguarded during the previous week's solar activity (DOY 067 1124z). This OCR was last executed on 01/26/2012. ======================================================================== Activities: Data Capture: 100% DOY 064-071 2012 During last week's solar storm: * CRIS Image Intensifier safeguarded Wednesday 3/7/2012 (DOY 067 1124z) and was turned back on Monday 3/12/2012 (DOY 072 1915z). * ULEIS shutter autonomously closed and reopened Wed Mar 07 2012, DOY 067 09:23:08 closed to 25% Wed Mar 07 2012, DOY 067 09:53:00 closed to 6% Wed Mar 07 2012, DOY 067 10:25:00 closed to 1% Sun Mar 11 2012, DOY 071 06:03:24 opened to 6% Sun Mar 11 2012, DOY 071 19:56:44 opened to 25% Sat Mar 12 2012, DOY 072 08:51:08 closed to 6% Sat Mar 12 2012, DOY 072 22:34:35 opened to 25% Tue Mar 13 2012, DOY 073 10:14:19 opened to 100% * SIS real time rates displayed by NOAA SWPC maxed out on Thursday 3/8/2012 0800z-1400z. Note that the complete SIS science data is not impacted by the limit in the real-time rates. * Star scanner false star count tripled on Thursday 3/8/2012. The star scanner typically sees 15-20 false stars every 16 seconds and was reading 45-60 false stars on Thursday. The star scanner discards the false stars using internal logic and only valid stars were downlinked in telemetry. Note, the star scanner false star count had maxed out at 255 during the 7/14/2000 solar storm. DSN performed maintenance on their Data Capture and Delivery system. All data was received in the MMOC. But the IDR (Intermediate Data Record) files on the DSN File Delivery Service (FDS) did not have all of the data. ACE Science Center receives IDR files from DSN via the FDS. DSN was notified and the IDR files were recreated with all of the data for ASC. Work continues to validate WS1 for ACE. A command test was performed on Friday 03/09/2012. Commands were successfully received by the spacecraft. Work continues on setting up ranging and updating the MMOC configuration. ======================================================================== Anomalies: None