STEREO Weekly Meeting Minutes for 2012-03-13 (Week 11) ANNOUNCEMENTS ------------- * None INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 10 (Mar 5-11) * On day 065 (Mar 5), during the DSS-62 support for Ahead, telemetry lock was lost intermittently beginning at 0618z through 0632z. ESA is investigating. This anomaly resulted in the loss of several minutes of SECCHI SSR data. This was the first operational pass with the ESA Cebreros station. * On day 065 (Mar 5), the 45th momentum dump for Ahead was successfully executed at 1800Z, which imparted a delta V of 0.0699 m/sec. * On day 069 (Mar 9), the SECCHI Ahead instrument reset at 04:12:00z. The SECCHI team reconfigured the instrument to operational mode at 069-1800z. This was the 27th reset of SECCHI on the Ahead spacecraft. * On day 065 (Mar 5), during the DSS-45 support for Behind, turbo decoder lock was lost intermittently beginning at 0356z through 0719z. This anomaly resulted in the loss of 130 frames of SSR data. See DR# N107960 for more information. * On day 066 (Mar 6), during the DSS-26 support for Behind, the antenna was stowed due to high winds at 2155z. After the winds subsided, telemetry lock was re-established at 0145z. SSR pointers were reset to minimize science data loss. This anomaly resulted in the loss of 3.8 hours of real-time telemetry, commanding, and tracking data and the SSR data loss listed below. See DR# G112439 for more information. IMPACT reached 95% full: 4.4 hours beginning at 067-2224z SECCHI data loss: 2.3 hours beginning at 068-0010z SWAVES reached 100% full: 3.5 hours beginning at 067-2247z * The SWAVES team reports that they do not see any problems with data loss during the above period. That may be because the data was playing back in realtime at the time. * On day 071 (Mar 11), during the DSS-65 support for Behind, turbo decoder lock was lost intermittently at 1450z through 1905z. This anomaly resulted in the loss of 48 frames of SSR data. A DR has been requested. * On day 068 (Mar 8), the 39th momentum dump for Behind was successfully executed at 1600Z, which imparted a delta V of 0.0691 m/sec. * The average daily SSR playback volume during the week was 5.0 gigabits for Ahead, and 4.6 gigabits for Behind. Week 11 (Mar 12-18) * Ahead has 70 meter passes on Monday, Mar 12 (D63), Wednesday, Mar 14 (D63), Saturday, Mar 17 (D63), and Sunday, Mar 18 (D43). There are 10 passes during the week, and overall coverage is nominal. An ESA New Norcia pass is scheduled for Thursday, Mar 15. * Behind has 70 meter passes on Monday, Mar 12 (D43 at 720 kbps), Tuesday, Mar 13 (D63), and Friday, Mar 16 (D63 at 720 kbps). There are 11 passes during the week, and overall coverage is nominal. The station 65 pass on Wednesday, Mar 14, and the station 24 pass on Thursday, Mar 15, will both be carried out at 240 kbps. Week 12 (Mar 19-25) * Ahead has 70 meter passes on Tuesday, Mar 20 (D43 at 720 kbps), Friday, Mar 23 (D43), and Sunday, Mar 25 (D43 at 720 kbps). There are 9 passes during the week, and overall coverage is nominal. * Behind has 70 meter passes on Monday, Mar 19 (D63), Tuesday, Mar 20 (D63), Friday, Mar 23 (D43), Saturday, Mar 24 (D63), and Sunday, Mar 25 (D63). There are 11 passes during the week, and overall coverage is nominal. The station 54 pass on Wednesday, Mar 21, will be carried out at 240 kbps. Week 13 (Mar 26-Apr 1) * Early on Monday, Mar 26, there will be a test of the backup communications link with ESA during the New Norcia pass. * There will be return-to-service track for station 14 on 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 11 passes during the week. Coverage will be short for SECCHI on Wednesday and Thursday, Mar 28-29, due to only a four 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, 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 5 N-m-s. The actual date of perihelion is Friday, Apr 6. * 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 8 tracks during the week, and overall coverage is nominal. * 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. 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 10 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. * Behind has 70 meter passes on Tuesday, May 1 (D63 at 720), Wednesday, May 2 (D63, D14 at 720 kbps), and Saturday, May 5 (D63 at 720 kbps). There are 8 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. Other * Comet SWAN is expected to enter the fields-of-view of the SECCHI COR2 and COR1 coronagraphs sometime today or tomorrow. It has already passed through HI1-B. This is a member of the same Kreutz sungrazing comets which make up the majority of the comets seen by the coronagraphs, but is unusual because it was first discovered by the SWAN instrument on SOHO, and is the only Kreutz comet known to have been seen by SWAN. It is expected to be a bright comet, but not as bright as the recent Comet Lovejoy. * SECCHI noticed small offpoints in the images just before the recent momentum dumps on both spacecraft. It is believed that this is due to the disabling of the guide telescope five minutes before the dump. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 11: M Mar 12 (072) T Mar 13 (073) W Mar 14 (074) T Mar 15 (075) F Mar 16 (076) S Mar 17 (077) S Mar 18 (078) ------------------------------------------------------------------------------- Scheduled activities for Week 12: M Mar 19 (079) T Mar 20 (080) W Mar 21 (081) T Mar 22 (082) F Mar 23 (083) S Mar 24 (084) S Mar 25 (085) ------------------------------------------------------------------------------- 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) ------------------------------------------------------------------------------- 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