ACE Weekly 09/29/2010 - 10/04/2010 All ACE spacecraft subsystems are performing nominally. Note: ACE Weekly Reports will now cover the week ending on Monday The previous reports covered the week ending on Tuesday ======================================================================== Orbit/Attitude: No maneuver was completed this week. The next attitude maneuver is scheduled for Friday 10/15/2010. ======================================================================= OCRs: None ======================================================================== Activities: Data Capture: 100% DOY 269-276 2010 DSN has requested a fourth Tracking, Telemetry & Command (TTC) Project Interface Test (PIT). Unfortunately, we cannot find antenna time for the PIT. The first PIT was successful when connecting through the RNS which is the current operational route. The last 2 PITs had been unsuccessful when connecting through the future DCD route. The transition to the DCD is still a month or so away. Options for more testing are still being investigated. ======================================================================== Anomalies: DOY 274 10/01/2010 S-ACE-0535 G10-0052 SLE CMDs Not Transmitted DSS-54 had successfully transmitted commands at the beginning of the pass (0830-0842z). 12 minutes after Beginning of Track, the ground S-Band Exciter (used for uplink) had an error and all subsequent commands were rejected by the station (DR#M105974). This problem last occurred 09/04/2010 (AR#G10-0044 DR#N106529). IMPACT: SSR playback had been started and completed without problems. Final state-of-health commanding performed on the following day's pass. Note on SLE CMDs Not Transmitted This problem is similar to the problem SOHO has been experiencing with DSN. The problem can be fixed by disconnecting and reconnecting the SLE FCLTU connection. SOHO has updated their automation software to handle this problem. On DOY 280, DSN will test the CSET directive to see if this breaks the bind and causes the MMOC to automatically reconnect. Also, MOCR 222 has been submitted for the MMOC to automatically disconnect and reconnect SLE FCLTU when commands are rejected by the station. DOY 276 10/03/2010 S-ACE-0536 G10-0053 ITOS tm_controller ITOS was unable to process telemetry due to a "timeout reading from tm_controller". ITOS was restarted before beginning of track. (DR CDSID#00027515) IMPACT: Manual intervention required. No delay in activities. Update on ITOS tm_controller. The FOT is investigating the possibility that ITOS DR CDSID#00027701 "event/postmaster process CPU usage" is a contributing factor to the "timeout reading from tm_controller" problem. All remote event windows have been disconnected and this has significantly reduced the CPU usage on the prime computer. The prime computer's event log can be checked by manually clicking the "connect" button on the remote computer and clicking the "disconnect" button when done. The CPU usage only becomes a problem when the remote event window is connected over several days. DOY 277 10/04/2010 S-ACE-0537 G10-0054 DSS-27 Transmitter RED DSS-27 transmitter was declared RED earlier on DOY 277. The transmitter was expected to be out for the entire week, but the station was able to provide an uplink 1.5 hours after the scheduled ACE Beginning Of Track. (DR#G110598/G110597) IMPACT: If the DSS-27 transmitter was RED for the entire week, it would have been very difficult to find antenna time (5 of the 7 ACE passes in Week 40 were with DSS-27). With the shortened pass on DOY 277, the remaining 40 minutes of the SSR playback will be completed on the next pass (40 minutes = 6.7 hours of playback data.)