ACE Weekly 09/18/2012 - 09/24/2012 All ACE spacecraft subsystems are performing as expected. ======================================================================== Orbit/Attitude: Type Attitude Date 09/24/2012 DOY 268 2012 Thrusters 2R 4R+ 4R- Duration 17:28 min Start 17:26:11z Stop 17:43:39z HGAStart -8.06deg HGAStop +8.34deg SunStart 18.23deg SunStop 5.01deg SpinStart 5.0626rpm SpinStop 5.0669rpm Nutation 0.16deg Firing 89 pulses FuelUsed 0.2680lbs FuelRemain 119.4644lbs FinalSCMass 1353.724lbs The next attitude maneuver is scheduled for Monday 10/08/2012. Signal strength: SNR = 8dB, antenna angle = +8.34deg, DSS-27 (in line with expectations) ======================================================================== OCRs: DOY 256 (09/12/2012) MOCR 481 Maneuver target 9 degree antenna angle Attitude maneuvers will now target a 9 degree antenna angle. Increasing the antenna angle from 8 degrees (DSS-27 SNR~9dB) to 9 degrees (DSS-27 SNR~7dB) lowers the downlink signal strength by ~2dB. This still provides sufficient downlink signal strength. (DSN has been able to lock onto the ACE signal at -2dB.) The operations team is currently using the extra degree to decrease the number of maneuvers performed (i.e. the antenna angle goes to zero between maneuvers). If ACE Management approves the new mission constraint of maximizing the sun angle (with weekly maneuvers), the spacecraft antenna angle will always be kept between 7 and 9 degrees. ======================================================================== Activities: Data Capture: 100% DOY 260-267 2012 ======================================================================== Anomalies: DOY 263 09/19/2012 S-ACE-0647 G12-0009 DSN TLM SLE Provider The MMOC SLE Software (MUS) was unable to connect to DSN TLM SLE Provider (ECONNREFUSED). The FOT requested that JPL restart their SLE process which fixed the problem. This problem last occurred on 9/15/2012. IMPACT: Manual intervention required. No delay in activities since the problem was caught before Beginning Of Track (BOT). DOY 268 09/24/2012 S-ACE-0651 G12-0013 Procedure halt due to error MOCR 485 updated the pass procedures (ace_pass.proc & pass_setup.proc ) to use a single variable (PID_LIST) for storing the process IDs that need to be killed at the end of the pass. Syntax errors that were discovered during testing were not properly corrected in the procedure that was CMd. IMPACT: PID_LIST was manually updated during the pass and the procedures were corrected after the pass.