STEREO Weekly Meeting Minutes for 2013-12-24 (Week 52) ANNOUNCEMENTS ------------- * The regularly scheduled weekly telecon for Dec 31 has been cancelled, due to the holidays. The next telecon will be on Jan 7. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 51 (Dec 16-22) * On day 350 (Dec 16), during the DSS-34 support for Ahead, turbo decoder lock was lost intermittently beginning at 0600z through 0602z. This anomaly resulted in the loss of 676 frames of SSR data. See DR #N109252 more information. * On day 353 (Dec 19), during the DSS-54 support for Ahead, turbo decoder lock was lost intermittently beginning at 0747z through 1419z. This anomaly resulted in the loss of 2502 frames of SSR data. See DR #N109266 more information. * On day 355 (Dec 21), the DSS-54 support was deleted due to the antenna being declared RED and down for maintenance until 1500 UTC on December 27th to work on the azimuth drive points, which were making bad noises. Since then, it has been determined that there are no physical problem with the drive, only a problem with the pointing control software. Station 54 is back up as of yesterday (Dec 23) in ORANGE status. The maximum drive rate has been decreased from 0.8 to 0.3 degrees per second, which will not affect STEREO supports. * On day 353 (Dec 19), the 63rd momentum dump on Ahead was executed successfully at 1300Z, which imparted a delta V of 0.070 m/sec. * On day 350 (Dec 16), during the DSS-65 support for Behind, turbo decoder lock was lost intermittently beginning at 1100z through 1629z. This anomaly resulted in the loss of 694 frames of SSR data. See DR #N109253 more information. * On day 353 (Dec 19), during the DSS-55 support for Behind, turbo decoder lock was lost briefly at 1418z. This anomaly resulted in the loss of 145 frames of SSR data. See DR #N109264 more information. * On day 355 (Dec 21), during the DSS-55 support for Behind, turbo decoder lock was lost briefly at 1025z and again at 1536z. This anomaly resulted in the loss of four frames of SSR data. * On day 356 (Dec 22), during the DSS-55 support for Behind, turbo decoder lock was lost briefly at 1616z. This anomaly resulted in the loss of one frame of SSR data. * On day 352 (Dec 18), the 3rd annual battery conditioning event was conducted successfully at 1330z on the Behind spacecraft to redistribute the electrolytes within the nickel hydrogen battery cells. * On day 353 (Dec 19), the 58th momentum dump on Behind was executed successfully at 1500Z, which imparted a delta V of 0.059 m/sec. * The average daily SSR playback volume during the week was 3.5 gigabits for Ahead, and 3.3 gigabits for Behind. 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). * PLASTIC will do realtime commanding on the Behind spacecraft on Monday, Dec 30, to reduce their telemetry rate. The same will be done on Ahead using time-tagged commands. Week 02 (Jan 6-12) * The 19th high-gain antenna calibration will be performed on Ahead at 19:00 UT on Tuesday, Jan 7, and on Behind at 15:00 UT on Wednesday, Jan 8. Each will take about an hour. * 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 are scheduled for Thursday, Jan 9 (D43), Friday, Jan 10 (D63), and Saturday, Jan 10 (D63). 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 (D14), and Saturday, Jan 11 (D63). Two passes will be carried out at 160 kbps, both on Monday, Jan 6 (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, mainly Monday-Thursday, Jan 13-16. There are two 70 meter supports scheduled, on Friday, Jan 17 (D43), and Saturday, Jan 18 (D63). * Behind has 10 passes during the week. Overall coverage is short 15.2 hours, with the shortfalls occurring Monday-Friday. No 70 meter supports are scheduled. 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 is expected most days. No 70 meter supports are scheduled. 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). COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- 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: HGA calibration, 19:00 UT W Jan 08 (008) Behind: 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 the Ahead spacecraft 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: 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: 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