STEREO Weekly Meeting Minutes for 2013-12-17 (Week 51) ANNOUNCEMENTS ------------- * None. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 50 (Dec 9-15) * On day 343 (Dec 9), during the DSS-63 support for Ahead, no commanding or ranging was conducted due to a transmitter problem. See DR #M107603 more information. * On day 343 (Dec 9), during the DSS-65 support for Behind, turbo decoder lock was lost briefly at 14:30 UT. This anomaly resulted in the loss of one frame of SSR data. * On days 343-345 (Dec. 9-11) SECCHI rolls to observe comet ISON on both Ahead (30 degrees) and Behind (290 degrees) were executed successfully at 02:00 UT each day. These were the 4th-6th rolls for Ahead and the 9th-11th rolls for Behind. * On day 344 (Dec 10), after powering off the IMU at 06:25 UT following the comet ISON roll, the Ahead spacecraft began dropping fine-pointing lock intermittently. This behavior continued until the IMU was powered on at 11:25 UT in preparation for the upcoming Comet ISON roll. The G&C engineer has not identified the cause of the problem definitively, but reaction wheel 2 was at the lowest speed during this time period and there are known bearing lubrication issues when the wheels operate in low speed regions. The engineer team will continue to investigate the guidance and control performance. * On day 345 (Dec 11), IMPACT conducted real-time commanding at 15:28 UT to recover from a SEPT-N latch-up on Ahead, which occurred on day 338 at 07:33 UT. * On day 345 (Dec 11), the SSR science partitions on Behind filled as follows: SWAVES (Part 13) reached 100% full at 18:25 UT for 4.0 hours. PLASTIC (Part 17) reached 95% full at 18:21 UT for 4.2 hours. The primary cause was the accumulated shortage of track time throughout the week. * On day 346 (Dec 12), during the DSS-65 support for Behind, turbo decoder lock was lost briefly at 10:55 UT. This anomaly resulted in the loss of four frames of SSR data. * On day 346 (Dec 12), the SSR science partitions on Behind filled as follows: SWAVES (Part 13) reached 100% full at 04:57 UT for 7.1 hours. PLASTIC (Part 17) reached 95% full at 04:36 UT for 7.6 hours. The primary cause was the accumulated shortage of track time throughout the week. * On day 347 (Dec 13), the 28th SECCHI stepped calibration on Ahead was executed successfully at 04:05 UT for the midpoint in the orbit. * On day 347 (Dec 13), the SSR science partitions on Behind filled as follows: SWAVES (Part 13) reached 100% full at 03:53 UT for 2.1 hours. SWAVES (Part 13) reached 100% full at 12:06 UT for 10.1 hours. PLASTIC (Part 17) reached 95% full at 02:11 UT for 4.0 hours. PLASTIC (Part 17) reached 95% full at 11:21 UT for 10.8 hours. The primary cause was the accumulated shortage of track time throughout the week. * The average daily SSR playback volume during this week was 4.1 Gbits for Ahead and 2.7 Gbits for Behind. Week 51 (Dec 16-22) * The third battery discharge cycle on Behind is scheduled for Wednesday, Dec 18, starting at 13:30 UT. * The 63rd momentum dump on Ahead is scheduled for Thursday, Dec 19, with ignition at 13:00 UT. * The 58th momentum dump on Behind is scheduled for Thursday, Dec 19, with ignition at 15:00 UT. * Ahead has 13 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Dec 16 (D63), Tuesday, Dec 17 (D43 at 720 kbps), and Friday, Dec 20 (D63). * Behind has 12 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Tuesday, Dec 17 (D43), and Friday, Dec 20 (D43 at 720 kbps). The following passes will be carried out at 160 kbps, all using station 26: Wednesday, Dec 18, Friday, Dec 20, and Sunday, Dec 22. Week 52 (Dec 23-29) * APL will closed for the Christmas holiday starting the afternoon of Tuesday, Dec 24, and on Christmas Day, Dec 25. * The 27th SECCHI stepped calibration roll for Behind is scheduled for Thursday, Dec 26, starting at 13:10 UT. This is the aphelion roll. * Ahead has 10 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Dec 23 (D63), Tuesday, Dec 24 (D14), and Friday, Dec 27 (D63). The following passes will be carried out at 160 kbps: Monday, Dec 23 (D45), and Thursday, Dec 26 (D26). * Behind has 14 passes during the week, and overall coverage is nominal. A 70 meter pass is scheduled for Saturday, Dec 28 (D43 at 720 kbps). The following passes will be carried out at 160 kbps: Tuesday, Dec 24 (D26), Thursday, Dec 26 (D45), and Saturday, Dec 28 (D26). Week 01 (Dec 30-Jan 5) * APL will be closed for the New Year's Day holiday starting the afternoon of Tuesday, Dec 31, and on Jan 1. * Ahead has 8 passes during the week. Overall coverage is short 18.4 hours, between Monday-Friday, Dec 30-Jan 3. 70 meter passes are scheduled for Tuesday, Dec 31 (D63), and Friday, Jan 3 (D63). The station 26 pass on Sunday, Jan 5, will be carried out at 160 kbps. * Behind has 8 passes during the week. Overall coverage is short 16.4 hours, between Monday-Friday, Dec 30-Jan 3. 70 meter passes are scheduled for Saturday, Jan 4 (D63 at 720 kbps, D14). The following passes will be carried out at 160 kbps: Wednesday, Jan 1 (D25), and Sunday, Jan 5 (D25). * Data loss for Behind on days when there will be a shortfall will be about 50%. PLASTIC will look into cutting back on their record rate. Week 02 (Jan 6-12) * Ahead 19th high-gain antenna calibration at 19:00 UT on Tuesday, Jan 7. It will take about an hour. * Behind 19th high-gain antenna calibration at 15:00 UT Wednesday, Jan 8. * Ahead has 8 passes during the week. Overall coverage is short 13.6 hours, mainly between Sunday, Jan 5 (of Week 1) and Wednesday, Jan 8. 70 meter passes Thursday, Friday, and Sunday (Jan 9-11). There will be one pass at 160 kbps: Wednesday, Jan 8 (D34) * Behind has 11 passes during the week, and overall coverage is nominal. There are two 70 meter passes, scheduled for Tuesday, Jan 7, and Saturday, Jan 11. Two passes will be carried out at 160 kbps, both on Monday (D45 and D26) Week 03 (Jan 13-19) * The 64th momentum dump on Ahead is scheduled for Thursday, Jan 16 with ignition at 13:30 UT * Ahead has 7 passes during the week. Overall coverage is short 12.2 hours short, mainly Monday-Thursday There are two 70 meter supports scheduled, on Friday, Jan 17, and Saturday, Jan 18. * Behind has 10 passes during the week. Overall coverage is short 15.2 hours, with the shortfalls occurring Monday-Friday. No 70 meter supports. The following passes will be carried out at 160 kbps: Monday, Jan 13 (D26), Tuesday, Jan 14 (D25), and Wednesday, Jan 15 (D55) Week 4 (Jan 20-26) * The 59th momentum dump on Behind is scheduled for Monday, Jan 20, with ignition at 23:00 UT. * Ahead has 9 passes during the week. Overall coverage is short 16.4 hours, spread throughout the week except Saturday. 30-40% data loss most days. No 70 meter supports. Two passes will be carried out at 160 kbps, both on Saturday, Jan 25 (D16 and D45) * Behind has 10 passes during the week. Overall coverage is short 10.5 hours, with the shortfall Wednesday-Friday. No 70 meter passes are scheduled. The following passes will be carried out at 160 kbps: Thursday, Jan 23 (D26), Friday, Jan 24 (D26), Saturday, Jan 25 (D55), and Sunday, Jan 26 (D26). Other A request has been made to put STEREO on ESA's Priority Zero list for antenna time. This would mean STEREO could get time that happened to be available, but would be bumped if any other missions needed the time. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 51: M Dec 16 (350) T Dec 17 (351) W Dec 18 (352) Behind: Battery discharge cycle, 13:30 UT T Dec 19 (353) Momentum dumps: Ahead, 13 UT, Behind 15 UT F Dec 20 (354) S Dec 21 (355) S Dec 22 (356) ------------------------------------------------------------------------------- Scheduled activities for Week 52: M Dec 23 (357) T Dec 24 (358) W Dec 25 (359) Christmas T Dec 26 (360) Behind: SECCHI stepped calibration roll, 13:10 UT F Dec 27 (361) S Dec 28 (362) S Dec 29 (363) ------------------------------------------------------------------------------- Scheduled activities for Week 01: M Dec 30 (364) T Dec 31 (365) W Jan 01 (001) New Year T Jan 02 (002) F Jan 03 (003) S Jan 04 (004) S Jan 05 (005) Notes: * Significant telemetry shortages are expected for both spacecraft during the week. ------------------------------------------------------------------------------- Scheduled activities for Week 02: M Jan 06 (006) T Jan 07 (007) Ahead: 19th HGA calibration, 19:00 UT W Jan 08 (008) Behind: 19th HGA calibration, 15:00 UT T Jan 09 (009) F Jan 10 (010) S Jan 11 (011) S Jan 12 (012) Notes: * Significant telemetry shortages are expected for Ahead during the week. ------------------------------------------------------------------------------- Scheduled activities for Week 03: M Jan 13 (013) T Jan 14 (014) W Jan 15 (015) T Jan 16 (016) Ahead: 64th momentum dump, 13:30 UT F Jan 17 (017) S Jan 18 (018) S Jan 19 (019) Notes: * Significant telemetry shortages are expected for both spacecraft during the week. ------------------------------------------------------------------------------- Scheduled activities for Week 04: M Jan 20 (020) Behind: 59th momentum dump, 23:00 UT T Jan 21 (021) W Jan 22 (022) T Jan 23 (023) F Jan 24 (024) S Jan 25 (025) S Jan 26 (026) Notes: * Significant telemetry shortages are expected for both spacecraft during the week. ------------------------------------------------------------------------------- Upcoming events: 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 * Sep 07-Nov 15 Behind: Passage of Comet Siding Spring through HI2-B * Oct 15 Behind: End use of 480 kbps on 70 m DSN subnet * Oct 17 Behind: Comet Siding Spring encounter with Mars 2015: * Jan 20 - Mar 28 (TBC) Behind: Spacecraft behind Sun * Mar DAWN - Ceres arrival * 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 * Jul Juno arrival at Jupiter 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