ACE Weekly 02/20/2008 - 02/26/2008 All ACE spacecraft subsystems are performing nominally. ============================================================================ Orbit/Attitude: Type Attitude Date 02/20/2008 DOY 051 2008 Thrusters 2R 4R+ 4R- Duration 15:42 min Start 13:49:02z Stop 14:04:44z HGAStart -8.20deg HGAStop +7.56deg SunStart 6.21deg SunStop 16.68deg Nutation 0.23deg Firing 80 pulses FuelUsed 0.2550lbs FuelRemain 151.3136lbs FinalSCMass 1385.573lbs The next attitude maneuver is scheduled for Thursday 03/06/2008. Note that the pre-maneuver HGA aspect angle was 8.2 degrees. The High-Gain Antenna performance continues to behave as expected. At this angle, the downlink SNR drops by approximately 2dB per degree. Beyond 10 degrees, the antenna performance drops precipitously. HGA Angle Downlink SNR (26m DSS-66) preman -8.20deg 7.5dB postman +7.56deg 8.8dB =========================================================================== OCRs: None ============================================================================ Activities: None ============================================================================ Anomalies: Update G08-0019 AC1WS3 failure Operations continue on String 3 while waiting for String 1 configuration after the workstation failure. Update G08-0024 DSS-27 Red DOY 050 The SSR failover resulted in a 32 second gap (2008-051 10:39:47-10:40:18); no clock calibration reports for DOY 050 and 051; and no attitude/orbit report for DOY 050. Unfortunately, no additional DSN time was available and SSR playback was not caught up until Saturday DOY 054.