ACE Weekly 03/02/2007 - 03/08/2007 All ACE spacecraft subsystems are performing nominally. ============================================================================ Orbit/Attitude: Type Attitude Date 03/05/2007 DOY 064 2007 Thrusters 2R 4R- 4R+ Duration 9:54 min Start 15:20:07z Stop 15:30:01z StartHGA -4.96 deg StopHGA +6.30 deg Firing 50 pulses FinalSCMass 1392.205lbs The next attitude maneuver is scheduled for Friday, 03/16/2007. Station-keeping maneuver #43 is scheduled for Thursday, 03/29/2007. ============================================================================ OCRs: DOY 067 (03/08/2007) SC_07_001 The High Gain Antenna (HGA) constraint has been increased from 6.5 degrees to 8.0 degrees. Analysis of historical data and HGA performance indicates that Signal to Noise Ratio will drop from 9dB to 6dB for high-rate data on DSS-27 and 26m antennas. This will still provide sufficient link margin. The number of attitude maneuvers will be reduced from ~40 to ~33 by extending the minimum time between maneuvers from 9 to 10 days. Nine days was insufficient to extend maneuver dates beyond 1 week + 1 weekend. Less frequent attitude maneuvers will have corresponding longer burns. The HGA constraint was last increased from 4.5 degrees to 6.5 degrees in 2002. ============================================================================ Activities: RIONET * Testing and configuration of String 3 continues. * Additional firewall rules have been found that will need to be updated. * String 2 conversion is targeted for April 18, 2007. ROBOTT * Testing of the recent patch (v1.0.3) is nearing completion. This patch will allow ROBOTT to work with the RIONet (CDSID#22954 and #23091). Space Link Extension (SLE) - ACE SLE version 2.1 was delivered to the Library on April 28, 2006. Installation in the ACE MOC will not occur until after the MOC is converted to the RIONET. ============================================================================ Anomalies: DOY 061 03/02/2007 S-ACE-0156 G07-0017 ROBOTT/C&C Froze ROBOTT froze after procedure S_OPS_PLBK_COMPLETE completed (EOT-5minutes). RTMON restart not performed since 5 minutes before End of Track. CDSID#00021192 IMPACT: This is a recurring issue that the ROBOTT developers are aware of. Procedure G_ACEDOWN not performed.