STEREO Weekly Meeting Minutes for 2012-03-27 (Week 13) ANNOUNCEMENTS ------------- * Tracking support approval for the use of the ESA stations by STEREO has been extended through the end of 2012. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 12 (Mar 19-25) * On day 079 (Mar 19), during the DSS-25 support for Ahead, turbo decoder lock was lost briefly at 1810z. This anomaly resulted in the loss of one frame of SSR data. See DR# N107984 for more information. * On day 080 (Mar 20), for the DSS-43 support for Ahead, AOS was delayed 2.7 hours due as the antenna was declared red due to a mechanical problem. At last week's telecon, it was feared that the entire pass would be lost, but this was not the case. Telemetry lock was established at 2229z and the SSR pointers were repositioned. Later in the support, the turbo decoder lost lock briefly at 2307z. Two ESA supports were added for DOY 084 to minimize SSR data loss. This anomaly resulted in the loss of 2.7 hours of commanding and tracking data and 103 frames of SSR data. See DR# C108599 and N107991 for more information. * On day 081 (Mar 21), during the DSS 15 support for Ahead, the transmitter tripped off-line at 1831z due to an alarm condition. The alarm was cleared at 2001z and the track continued one-way only. This anomaly resulted in the loss of 2 hours 14 minutes of commanding and two-way tracking data and several minutes of SSR data for each instrument. See DR# G112469 for more information. * On day 082 (Mar 22), during the DSS-55 support for Ahead, turbo decoder lock was lost intermittently at 0745z and again at 0819z. This anomaly resulted in the loss of six frames of SSR data. See DR# N107992 for more information. * On day 083 (Mar 23), during the DSS-55 support for Ahead, turbo decoder lock was lost briefly at 0804z. This anomaly resulted in the loss of three frames of SSR data. See DR# N107994 for more information. * On day 084 (Mar 24), the DSS-62 support (ESA Cebreros) was downlink only as the track was scheduled too early due to a problem with the generation of the viewperiod file. The schedule would have called for the transmitter to be turned on below 10 degrees of elevation, which is not allowed. The DSN is correcting their software, and it should be in effect next week. They will assume 10 degrees until they have an elevation map. * On day 080 (Mar 20), during the DSS-63 support for Behind, turbo decoder lock was lost briefly at 1150z. This anomaly resulted in the loss of two frames of SSR data. See DR# N107987 for more information. * On day 081 (Mar 21), during the DSS-54 support for Behind, turbo decoder lock was lost briefly at 1333z. This anomaly resulted in the loss of seven frames of SSR data. See DR# N107989 for more information. * On day 082 (Mar 22), during the DSS-65 support for Behind, turbo decoder lock was lost briefly at 1645z and again at 1827z. This anomaly resulted in the loss of seven frames of SSR data. See DR# N107996 for more information. * On day 084 (Mar 24), during the DSS-25 support for Behind, turbo decoder lock was lost briefly at 0018z. This anomaly resulted in the loss of one frame of SSR data. A DR has been requested. * On day 085 (Mar 25), during the DSS-63 support for Behind, initial telemetry lock was delayed 6 minutes due to a problem at the station. This anomaly resulted in the loss of several minutes of SECCHI SSR data. See DR# M106668 for more information. * The average daily SSR playback volume during the week was 4.6 gigabits for Ahead, and 5.0 gigabits for Behind. Week 13 (Mar 26-Apr 1) * Early on Monday, Mar 26, there was a test of the backup communications link with ESA during the New Norcia pass. From the MOC perspective, this test was successful. * There will be return-to-service track for station 14 tomorrow (Wednesday, Mar 28). This track will be shadowed by the operational track using station 34, but the commanding link will be on station 14. The telemetry rate will be 160 kbps to be consistent with both stations. * Ahead has 70 meter tracks on Friday, Mar 30 (D43) and Sunday, Apr 1 (D14). There are 12 passes during the week and overall coverage is nominal. The station 15 pass on Friday, Mar 30, and the station 34 pass on Saturday, Apr 1, will both be carried out at 240 kbps. * Behind has 70 meter passes on Tuesday, Mar 27 (D43), Saturday, Mar 31 (D63 at 720 kbps), and Sunday, Apr 1 (D14 at 720 kbps). There are 12 passes during the week. Coverage will be short for SECCHI on Wednesday and Thursday, Mar 28-29, due to only a 4-5 hour pass on each day. In situ instruments should be OK. The station 15 pass on Monday, Mar 26, the station 26 pass on Wednesday, Mar 28, and the station 65 pass on Thursday, Mar 29, will all be carried out at 240 kbps. ESA New Norcia passes are scheduled for Monday, Mar 26, Thursday, Mar 29, and Friday, Mar 30. Week 14 (Apr 2-8) * The 21st SECCHI stepped calibration roll for Ahead (at perihelion) is scheduled for Tuesday, Apr 3, starting at 14:45 UT. System momentum will be about 5 N-m-s. The actual date of perihelion is Friday, Apr 6. The roll will take about 3 hours. * Sunday, Apr 8, is Easter. Many people at APL will be off that weekend, including the preceeding Friday, Apr 6, so the instrument teams should give advance notice of any needed realtime commanding. * Ahead has 70 meter tracks on Tuesday, Apr 3 (D43), Wednesday, Apr 4 (D43), Friday, Apr 6 (D14), and Sunday, Apr 8 (D63, D14 at 720 kbps). There are 12 tracks total and overall coverage is nominal. * Behind has 70 meter tracks on Monday, Apr 2 (D63 at 720 kbps), Tuesday, Apr 3 (D14), Thursday, Apr 5 (D63 at 720 kbps), and Friday, Apr 6 (D63 at 720 kbps). There are 10 tracks during the week and overall coverage is nominal. The station 55 pass on Tuesday, Apr 3, the station 54 pass on Wednesday, Apr 4, and the station 15 pass on Sunday, Apr 8, will all be carried out at 240 kbps. Week 15 (Apr 9-15) * The 40th momentum dump for Behind is scheduled for Wednesday, Apr 11, starting at 15:00 UT. * Ahead has 70 meter tracks on Monday, Apr 9 (D14), Tuesday, Apr 10 (D63), Wednesday, Apr 11 (D63), Friday, Apr 13 (D14), Saturday, Apr 14 (D14), and Sunday, Apr 15 (D14). There are 8 tracks during the week, and overall coverage is nominal. * Behind has 70 meter tracks on Monday, Apr 9 (D63), Wednesday, Apr 11 (D63), Thursday, Apr 12 (D63), Friday, Apr 13 (D63), Saturday, Apr 14 (D63), and Sunday, Apr 15 (D14), all at 720 kbps. There are 8 tracks during the week, and overall coverage is nominal. Week 16 (Apr 16-22) * The 46th momentum dump on Ahead is scheduled for Apr 17, with ignitition at 16:00 UT. * Ahead has 70 meter tracks on Wednesday, Apr 18 (D14), Friday, Apr 20 (D63), Saturday, Apr 21 (D63), and Sunday, Apr 22 (D14). There are 10 tracks during the week, and overall coverage is nominal. ESA Cebreros passes are scheduled for Thursday, Apr 19, and Friday, Apr 20. * Behind has 70 meter tracks on Monday, Apr 16 (D63), Wednesday, Apr 18 (D14 at 720 kbps), and Sunday, Apr 22 (D14 at 720 kbsp). There are 12 tracks during the week, and overall coverage is nominal. The station 25 pass on Saturday, Apr 21, and the station 65 pass on Sunday, Apr 22, will be carried out at 240 kbps. The ESA Cebreros pass originally scheduled for Friday, Apr 20 has been cancelled since it was so short, just over an hour. Week 17 (Apr 23-29) * There is a 2.75 hour return-to-service track for station 26 on Ahead on Monday, Apr 23. This track will not be shadowed, and there will be no SSR playback. * Ahead has 70 meter tracks on Monday, Apr 23 (D14), Tuesday, Apr 24 (D14, D43), Wednesday, Apr 25 (D63), Thursday, Apr 26 (D63 at 720 kbps), Friday, Apr 27 (D63), Saturday, Apr 28 (D63), and Sunday, Apr 29 (D63). There are 10 tracks during the week, and overall coverage is nominal. * Behind has 70 meter tracks on Monday, Apr 23 (D63), Tuesday, Apr 24 (D14 at 720 kbps), Wednesday, Apr 25 (D14 at 720 kbsp), Thursday, Apr 26 (D14 at 720 kbps), Friday, Apr 27 (D63 at 720 kbps), Saturday, Apr 28 (D14), and Sunday, Apr 29 (D63 at 720 kbps). There are 8 passes during the week, and overall coverage is nominal. Week 18 (Apr 30-May 6) * The ability to downlink from Ahead with 34 meter stations through the low-gain antenna will end on Monday, Apr 30. The same happened on Behind last fall. * Ahead has 70 meter tracks on Monday, Apr 30 (D14 at 720 kbps), Thursday, May 3 (D14), and Saturday, May 5 (D63 at 720 kbps). There are 11 passes during the week, and the overall coverage is nominal. The station 24 pass on Tuesday, May 1, will be carried out at 240 kbps. An ESA Cebreros pass is scheduled for Friday, May 4. * Behind has 70 meter passes on Tuesday, May 1 (D63 at 720), Wednesday, May 2 (D63, D14 at 720 kbps), Thursday, May 3 (D63), and Saturday, May 5 (D63 at 720 kbps). There are 10 passes during the week, and overall coverage is nominal. The station 55 pass on Monday, Apr 30, and the station 54 passes on Friday, May 4, and Sunday, May 6, will all be carried out at 240 kbps. Passes with the ESA New Norcia station are scheduled for Monday, Apr 30, and Friday, May 4. Week 19 (May 7-13) * Ahead has 70 meter passes on Monday, May 7 (D63 and D14), Wednesday, May 9 (D63), Friday, May 11 (D14 at 720 kbps), and Sunday, May 13 (D14 at 720 kbps). There are 11 passes during the week, and overall coverage is nominal. The station 54 passes on Tuesday, May 8 and Thursday, May 10, and the station 26 pass on Thursday, May 10 will be carried out at 240 kbps. * Behind has 70 meter passes on Monday, May 7 (D63 at 720 kbps), Tuesday, May 8 (D63 at 720 kbps), Thursday, May 10 (D14), Friday, May 11 (D63), and Sunday, May 13 (D63). There are 10 passes during the week, and overall coverage is nominal. The station 55 passes on Wednesday, May 9 and Saturday, May 12, the station 25 pass on Saturday, May 12, and the station 24 pass on Sunday, May 13, will all be carried out at 240 kbps. Other * There will a STEREO Science Working Group telecon on Thursday, Mar 29. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 13: M Mar 26 (086) T Mar 27 (087) W Mar 28 (088) Ahead: Return-to-service track for station 14 at 160 kbps T Mar 29 (089) F Mar 30 (090) S Mar 31 (091) S Apr 01 (092) ------------------------------------------------------------------------------- Scheduled activities for Week 14: M Apr 02 (093) T Apr 03 (094) Ahead: SECCHI stepped calibration roll, 14:45 UT W Apr 04 (095) T Apr 05 (096) F Apr 06 (097) Ahead: Perihelion S Apr 07 (098) S Apr 08 (099) Easter ------------------------------------------------------------------------------- Scheduled activities for Week 15: M Apr 09 (100) T Apr 10 (101) W Apr 11 (102) Behind: Momentum dump, 15:00 UT T Apr 12 (103) F Apr 13 (104) S Apr 14 (105) S Apr 15 (106) ------------------------------------------------------------------------------- Scheduled activities for Week 16: M Apr 16 (107) T Apr 17 (108) Ahead: Momentum dump, 16:00 UT W Apr 18 (109) T Apr 19 (110) F Apr 20 (111) S Apr 21 (112) S Apr 22 (113) ------------------------------------------------------------------------------- Scheduled activities for Week 17: M Apr 23 (114) Ahead: Return-to-service track for station 26. T Apr 24 (115) W Apr 25 (116) T Apr 26 (117) F Apr 27 (118) S Apr 28 (119) S Apr 29 (120) ------------------------------------------------------------------------------- Scheduled activities for Week 18: M Apr 30 (121) Ahead: End downlink with LGA on 34 meter stations T May 01 (122) W May 02 (123) T May 03 (124) F May 04 (125) S May 05 (126) S May 06 (127) ------------------------------------------------------------------------------- Scheduled activities for Week 19: M May 07 (128) T May 08 (129) W May 09 (130) T May 10 (131) F May 11 (132) S May 12 (133) S May 13 (134) ------------------------------------------------------------------------------- Upcoming events: 2012: * Jul DAWN - Vesta departure * Jul 11 Both: HGA calibration * Nov 4 Behind: Switch downlink rate to 120 kbps * Nov 13 Total solar eclipse, south Pacific 2013: * May 3 Ahead: Switch downlink rate to 120 kbps * Dec 12 Ahead: Mercury transit 2014: * Jan 20 Behind: End use of 480 kbps on 70 m DSN subnet * Apr 21 Behind: Resume use of 480 kbps on 70 m DSN subnet * Apr 29 Behind: Mercury transit * Oct 15 Behind: End use of 480 kbps on 70 m DSN subnet 2015: * Feb DAWN - Ceres arrival * Jan 20 - Mar 28 (TBC) Behind: Spacecraft behind Sun * Mar 17 - Jul 14 (TBC) Ahead: Spacecraft behind Sun * Jul 2 Behind: Resume use of 480 kbps on 70 m DSN subnet * Aug 25 - Oct 19 (TBC) Behind: Spacecraft behind Sun * Sep 25 Behind: End use of 480 kbps on 70 m DSN subnet * Jul DAWN - End of nominal mission 2016: * Apr 3 Behind: Resume use of 480 kbps on 70 m DSN subnet 2017: * Jul 11 Ahead: Switch downlink rate to 160 kbps * Jul 22 Behind: Switch downlink rate to 160 kbps 2018: * Mar 5 Ahead: Mercury transit