STEREO Weekly Meeting Minutes for 2012-10-16 (Week 42) ANNOUNCEMENTS ------------- * Significant coverage shortfalls for the Behind spacecraft are expected starting during week 46 and continuing through the end of the year. See below for details. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 41 (Oct 8-14) * On day 282 (Oct 8), during the DSS-55 support for Ahead, turbo decoder lock was lost intermittently beginning at 0801z through 0842z. Also during the support, the command bind was lost for two minutes at 0803z and again at 0920z. The turbo decoder anomaly resulted in the loss of four frames of SSR data. See DR# N108464 for more information. * On day 285 (Oct 11), during the DSS-55 support for Ahead, the command bind was lost for one minute at 0741z. See DR# N108468 for more information. This and the similar event on Oct 8 were due to the fiber optics temperatures exceeding their limits. The problem hasn't recurred since Oct 11, and the station is monitoring the situation. * On day 287 (Oct 13), during the DSS 63 support for Ahead, turbo decoder lock was lost intermittently beginning at 0641z through 0903z. This anomaly resulted in the loss of 72 frames of SSR data. See DR# N108471 for more information. * On day 288 (Oct 14), during the DSS 63 support for Ahead, turbo decoder lock was lost briefly at 0605z. This anomaly resulted in the loss of one frame of SSR data. See DR# N108472 for more information. * On day 288 (Oct 14), during the DSS 25 support, turbo decoder lock was lost briefly at 1555z. This anomaly resulted in the loss of one frame of SSR data. See DR# N108470 for more information. * The station 45 X-band laser is currently red. It is expected to be fixed before the next STEREO pass. If not, a signal loss of 2 dB is expected, which is within STEREO's margin. * On day 287 (Oct 13), SWAVES conducted real-time commanding on Ahead to load flight software to correct a signed integer problem that occurs when the instrument uptime exceeds a certain value. SWAVES was rebooted yesterday (Oct 15) at 14:00 UT to implement the software load. * On day 283 (Oct 9), the SSR science partitions on Behind filled as follows: SWAVES reached 100% full at 1121z for 6.7 hours. IMPACT reached 95% full at 1240z for 5.4 hours. * On day 284 (Oct 10), the SSR science partitions on Behind filled as follows: SWAVES reached 100% full at 2058z for 1.4 hours. * On day 285 (Oct 11) during the DSS-43 support for Behind, turbo decoder lock was lost intermittently beginning at 0350z through 0353z. This anomaly resulted in the loss of 61 frames of SSR data. See DR# N108469 for more information. * On day 287 (Oct 13), the SSR science partitions filled as follows: SWAVES reached 100% full at 1746z for 1.5 hours. * The average daily SSR playback volume during the week was 5.2 gigabits for Ahead, and 4.4 gigabits for Behind. Week 42 (Oct 15-21) * SWAVES-Ahead was rebooted yesterday (Oct 15) at 14:00 UT to activate the software load that was loaded in the previous week. * Scheduled maintenance was performed yesterday on the restricted IONET backup link. * Ahead has 70 meter passes on Monday, Oct 15 (D14), Wednesday, Oct 17 (D63), Saturday, Oct 20 (D63, D14), and Sunday, Oct 21 (D63). There are 14 passes during the week, and overall coverage is nominal. * Behind has 70 meter passes on Monday, Oct 15 (D43, D14), Tuesday Oct 16 (D14), Wednesday, Oct 17 (D63), Thursday, Oct 18 (D14), Saturday, Oct 20 (D14) and Sunday, Oct 21 (D63). There are 8 passes during the week, and overall coverage is nominal. An ESA New Norcia pass is scheduled for Friday, Oct 19. Week 43 (Oct 22-28) * The second refresh of the IMU EEPROMs will be performed during the week. The EEPROMs for IMU1 on both spacecraft will be refreshed on Wednesday, Oct 24, and those for IMU2 on both spacecraft will be refreshed on Thursday, Oct 25. * Oct 25 is the sixth launch anniversary of STEREO. * A software reset of the IMPACT/PLASTIC IDPU on Behind is scheduled for Saturday, Oct 27, during the station 15 pass. This will change the IDPU to run off of EEPROM to avoid bit-flip errors. This change has already been implemented on Ahead. It will take several hours to bring all the high voltages back up. * Ahead has 70 meter passes on Monday, Oct 22 (D63, D14), Tuesday, Oct 23 (D14), Wednesday, Oct 24 (D14), Friday, Oct 26 (D63), Saturday, Oct 27 (D63), and Sunday, Oct 28 (D63, D43 at 720 kbps). There are 14 passes during the week, and overall coverage is nominal. * Behind has 70 meter passes on Tuesday, Oct 23 (D63), Wednesday, Oct 24 (D63), Thursday, Oct 25 (D63), Friday, Oct 26 (D43), and Sunday, Oct 28 (D63). There are seven passes during the week, and overall coverage is nominal. An ESA New Norcia pass is scheduled for Monday, Oct 22. Week 44 (Oct 29-Nov 4) * The 51st momentum dump on Ahead is scheduled for Tuesday, Oct 30, with ignition at 16:00 UT. * Daylight savings time ends in the U.S. on Sunday, Nov 4. * Ahead has 70 meter passes on Monday, Oct 29 (D14), Tuesday, Oct 30 (D14), Wednesday, Oct 31 (D14), Friday, Nov 2 (D14), Saturday, Nov 3 (D63, D43), and Sunday, Nov 4 (D63). There are 11 passes during the week, and overall coverage is nominal. * Behind has 70 meter passes on Monday, Oct 29 (D14), Tuesday, Oct 30 (D63, D14), Thursday, Nov 1 (D63), Friday, Nov 2 (D43), Saturday, Nov 3 (D14), and Sunday, Nov 4 (D14). There are 9 passes during the week, and overall coverage is nominal. An ESA New Norcia pass is scheduled for Friday, Nov 2. Week 45 (Nov 5-11) * The nominal telemetry rate for Behind with 34 meter stations will drop from 160 kbps to 120 kbps starting Monday, Nov 5. The telemetry rate for high elevation passes will drop from 240 kbps to 160 kbps. The same change will be made for Ahead next spring. * The 46th momentum dump on Behind is scheduled for Tuesday, Nov 6, starting at 21:00 UT. * The times for the Ahead station 55 pass on Tuesday, Nov 6 have been shifted. Because of this, the pass will be carried out at 160 kbps. * Ahead has 13 passes during the week, and overall coverage is nominal. There are 70 meter passes on Monday, Nov 5 (D63), Tuesday, Nov 6 (D14), Wednesday, Nov 7 (D14), Friday, Nov 9 (D63), and Saturday, Nov 10 (D63, D43 at 720 kbps). An ESA New Norcia pass is scheduled for Sunday, Nov 11. * Behind has 8 tracks during the week, and overall coverage is nominal. There are 70 meter passes on Monday, Nov 5 (D63), Tuesday, Nov 6 (D14), Wednesday, Nov 7 (D43 at 720 kbps), Thursday, Nov 8 (D63), Friday, Nov 9 (D63), Saturday, Nov 10 (D14), and Sunday, Nov 11 (D14). The station 34 pass on Friday, Nov 9, will be the first pass to be carried out at 120 kbps, and the only one scheduled during the week. Week 46 (Nov 12-18) * Ahead has 13 passes during the week, and overall coverage is nominal. There are 70 meter passes on Tuesday, Nov 13, and Saturday, Nov 17, both using station D14. * Behind has 9 passes during the week, and overall coverage has a significant shortage of 16.3 hours over the course of the week. This is due to several station going down for maintenance all at the same time. Station 43 will be down for six months. Station 54 will be down for about a month, and is expected to be back up on day 344 (Dec 9). The ESA New Norcia station will also be going down for maintenance. Coverage will be scant for the entire week, but will be particularly tight on Monday, Nov 12, and Thursday, Nov 15. 70 meter stations are scheduled for Tuesday, Nov 13 (D14), Thursday, Nov 15 (D63), Saturday, Nov 17 (D14), and Sunday, Nov 18 (D63). An ESA Cebreros pass is scheduled for Monday, Nov 12. A weekly schedule for week 46 will be out later today (Oct 16) to assist the instrument teams in planning. Coverage shortfalls for Behind are expected to continue through the end of the year. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 41: M Oct 08 (282) T Oct 09 (283) W Oct 10 (284) T Oct 11 (285) F Oct 12 (286) S Oct 13 (287) S Oct 14 (288) ------------------------------------------------------------------------------- Scheduled activities for Week 42: M Oct 15 (289) T Oct 16 (290) W Oct 17 (291) T Oct 18 (292) F Oct 19 (293) S Oct 20 (294) S Oct 21 (295) ------------------------------------------------------------------------------- Scheduled activities for Week 43: M Oct 22 (296) T Oct 23 (297) W Oct 24 (298) T Oct 25 (299) F Oct 26 (300) S Oct 27 (301) S Oct 28 (302) ------------------------------------------------------------------------------- Scheduled activities for Week 44: M Oct 29 (303) T Oct 30 (304) Ahead: Momentum dump, 16:00 UT W Oct 31 (305) T Nov 01 (306) F Nov 02 (307) S Nov 03 (308) S Nov 04 (309) End of daylight savings time in U.S. ------------------------------------------------------------------------------- Scheduled activities for Week 45: M Nov 05 (310) Behind: Switch downlink rate to 120 kbps T Nov 06 (311) Behind: Momentum dump, 21:00 UT W Nov 07 (312) T Nov 08 (313) F Nov 09 (314) S Nov 10 (315) S Nov 11 (316) ------------------------------------------------------------------------------- Scheduled activities for Week 46: M Nov 12 (317) T Nov 13 (318) Total solar eclipse, south Pacific W Nov 14 (319) T Nov 15 (320) F Nov 16 (321) S Nov 17 (322) S Nov 18 (323) ------------------------------------------------------------------------------- Upcoming events: 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 * 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