ACE Weekly 01/20/2010 - 01/26/2010 All ACE spacecraft subsystems are performing nominally. ======================================================================== Orbit/Attitude: Type Attitude Date 01/26/2010 DOY 026 2010 Thrusters 2R 4R+ 4R- Duration 14:35 min Start 16:33:36z Stop 16:48:11z HGAStart -7.74deg HGAStop +8.07deg SunStart 6.52deg SunStop 17.99deg SpinStart 5.0518rpm SpinStop 5.0556rpm Nutation 0.11deg Firing 74 pulses FuelUsed 0.2333lbs FuelRemain 138.2224lbs FinalSCMass 1372.482lbs The next attitude maneuver and SK-53 are scheduled for Thursday 02/11/2010. ======================================================================= OCRs: None ======================================================================== Activities: Data Capture: 100% DOY 017-024 2010 DSN's Central Data Recorder (CDR) failed on Monday 01/18/2010 and the ACE Science Center (ASC) stopped receiving CDR files. The ACE MOC receives all data (realtime and playback) during the pass formatted as TLM-3-27 (same as the CDR). The ACE MOC data was modified slightly to match the CDR format (96 byte file header & 2 byte block padding) and sent to ASC. This was done for DOY 018-022. ASC received DOY 023 and DOY 024 from the DSN CDR (each 1 day late). DSN CDR delivery was up-to-date on DOY 025. The last time ASC needed data from the ACE MOC was DOY 073 2007, when the DSS-66 Ground Receipt Time was incorrect. The CDR file was re-sorted by the incorrect GRT and prevented the data from being processed by ASC. The ACE MOC data had not been resorted and was sent to ASC (with appropriate header/padding included). When ACE transitions to the MMOC, the MMOC will receive data via SLE and the CDR will save data in the 0161 format. SLE and 0161 data have different header formats. DSS-34 will be unavailable from DOY 027-111 (1/27/2010-04/21/2010). This leaves 5 DSN antennas for ACE to use. Of those 5, only DSS-45 is in the southern hemisphere. There should still be sufficient southern hemisphere ranging data for the Orbit Determination team. The start of operational testing in the MMOC is tentatively scheduled for Tuesday 02/16/2010 (DOY 047). All passes starting with DOY 047 will be taken from the MMOC. If there are significant problems, operations would switch back to the old MOC and DSN will be able to reload the configuration tables for the next day's pass. The Operations Readiness Review (ORR) is scheduled for 03/31/2010 ======================================================================== Anomalies: DOY 024 01/24/2010 S-ACE-0479 S10-0001 Increase in SBE_CT_A SSR A Single Bit Error Count (SBE_CT_A) increased from 525 to 540 and SCRUB_ERR_CT_A increased from 35 to 36 since last checked on DOY 022 (01/22/2010). SBE_CT is tracked as a measure of SSR health. IMPACT: Minimal. Single Bit Errors are automatically corrected by the SSR. No non-correctable errors (Hard Single Bit Errors & Double Bit Errors) have occurred throughout the mission. SBE_CT_A SBE_CT_B 1999 15 2000 2001 2002 2003 270 286 2004 858 2005 2006 2118 2007 510 3238 2008 4533 2009 525 6839 2010 540