ACE Weekly 10/05/2010 - 10/11/2010 All ACE spacecraft subsystems are performing nominally. ======================================================================== Orbit/Attitude: No maneuver was completed this week. The next attitude maneuver is scheduled for Friday 10/15/2010. ======================================================================= OCRs: None ======================================================================== Activities: Data Capture: 96.40% DOY 276-283 2010 There is a 6 hour 3 minute 5 second gap for DOY 280. 12:31:38 - 18:34:42 See Anomaly Reports: G10-0055, G10-0060 and G10-0061 Two smaller gaps due to ground station (DSN DR#G110650). Not redumped due to being behind in SSR playback. 342 seconds 2010-282-08:17:04 - 08:22:45 22 seconds 2010-282-08:22:51 - 08:23:12 There is a higher than normal risk of data loss from October 2010 through February 2011. If there are problems with the passes, it may not be possible to acquire additional DSN time. This is expected during winter months. See weekly reports on 01/25/2007, 12/25/2007 and 10/14/2008. Note, there was not as much competition for DSN antenna time last year; see weekly report on 12/15/2009. * Mars is on the opposite side of the sun, which occurs every 2 years. The viewperiods for the Mars missions (MRO, MEX, M01O, etc) and others (Messenger, New Horizons, Voyager, etc) overlap with with L1 missions (SOHO, WIND, ACE) for the next few months. * In the winter months, viewperiods from antennas in the northern hemisphere are shorter. Since 4 of the 6 antennas are in the northern hemisphere (Madrid, Spain & Goldstone, California), overall antenna time is reduced. * DSN continues a maintenance schedule where every antenna is unavailable during daylight hours one day each week. NOAA Space Weather Prediction Center does not have a backup antenna. NOAA SWPC currently has antenna time with NICT (Japan), DLR (Germany), and Wallops (Virginia). This week, NICT will be down on 10/09, 10/10 and 10/13 for maintenance. The network connection to the Air Force Satellite Control Network (AFSCN) was lost on September 1, 2010 with the closing of the Onizuka Air Force Base. There are plans to add a network through Vandenberg Air Force Base, but that has not been implemented. Note, the NOAA SWPC operations is separate from the Goddard flight operations, but this information is worth noting and therefore included in this weekly report. ======================================================================== Anomalies: DOY 280 10/07/2010 S-ACE-0538 G10-0055 DSS-24 Power Outage The DSN Goldstone complex experienced a 5 minute commercial power outage before generators came online. Tracking and uplink resumed after 76 minutes. DR#G110626 IMPACT: No realtime data to NOAA Space Weather for 76 minutes. 55 minutes of data dumped on the following pass (55 minutes = 9.1 hours of playback data). DOY 281 10/08/2010 S-ACE-0539 G10-0056 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. It appears that disconnecting remote event windows has not eliminated the tm_controller problem. (See last week's report) DOY 281 10/08/2010 S-ACE-0540 G10-0057 MUS CMD process terminated The MMOC SLE (MUS) cmd process (ace-d24-cmd) terminated unexpectedly 2 minutes after beginning of track. The MUS CMD process was restarted within 6 minutes. This last occurred on 08/28/2010 (AR#G10-0042) IMPACT: Manual intervention required. Activities delayed 6 minutes. DOY 281 10/08/2010 S-ACE-0541 G10-0058 SLE CMDs Not Transmitted DSS-24 had successfully transmitted commands at the beginning of the pass (1720-1836z). At 2013z, the ground station's SLE FCLTU Production State was interrupted. All subsequent commands were rejected by the station (DR#G110641). This problem last occurred 10/01/2010 (AR#G10-0052). MOCR 222 has been submitted for the MMOC to automatically disconnect and reconnect SLE FCLTU when commands are rejected by the station. IMPACT: SSR not commanded to Idle. See AR#G10-0059 DOY 281 10/08/2010 S-ACE-0542 S10-0008 SSR B Stuck in Playback When the SSR playback is longer than the pass, the SSR is commanded to idle before switching to the low-rate (RTSW) data format. Problems with the SLE CMD connection (AR#G10-0058) prevented SSR B from being commanded to Idle. When this occurs, the SSR is stuck in Playback. Impact: The ground procedures are designed to handle this contingency by idling the SSR at the beginning of the next support and redumping any missing data. This has occurred 5 other times in the past. 01/12/2005 AR#S05-0002 12/01/2005 AR#G05-0148 11/04/2008 AR#G08-0109 10/04/2009 AR#S09-0007 05/11/2010 AR#S10-0002 DOY 282 10/09/2010 S-ACE-0543 G10-0059 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. DOY 282 10/09/2010 S-ACE-0544 G10-0060 DSS-27 Transmitter RED DSS-27 transmitter was declared RED on DOY 280 due to being unable to move the antenna in either axis. (DR#G110646) IMPACT: The pass was lost. See AR#G10-0061 DOY 282 10/09/2010 S-ACE-0545 G10-0061 6 hours data loss The SSR playback was behind schedule by 55 minutes (=9 hours) due to the DSS-24 power outage on DOY 280. Some of that was caught up on the DOY 281 pass, but the SSR playback was still behind by 36 minutes (=6 hours). With DSS-27 RED on DOY 282, there was limited antenna time available and a 1-hour pass was scheduled for DSS-45. In the past, short passes have been taken manually. For example, see 9/22/2009 weekly concerning the LCROSS spacecraft emergency and manual pass on DOY 266 2009. On DOY 282 2010, however, no manual intervention occurred. IMPACT: The SSR ground procedures were executed without intervention. The ground procedures noted the limited time available and did not redump the 36 minutes of SSR carryover from the DOY 281 pass. DOY 284 10/11/2010 S-ACE-0546 G10-0062 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.