STEREO Weekly Meeting Minutes for 2013-07-30 (Week 31) ANNOUNCEMENTS ------------- * The planned work on the DMZ computers has been rescheduled for Monday, Aug 26, between 20-23 UT. This will require several reboots, and instrument teams can expect to need to reconnect. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 30 (Jul 22-28) * On day 203 (Jul 22), during the DSS-25 support for Ahead, telemetry was lost in the MOC due to a DCD failover that occurred between 1433z and 1555z. Due to uncertainty as to whether the data was being captured by the backup DCD, all SSR pointers were repositioned to the pre-anomaly locations. This pointer repositioning eventually resulted in 1.8 hours of SECCHI data loss. See DR #G114102 for more information. * On day 209 (Jul 28), during the DSS-26 support for Ahead, turbo decoder lock was lost briefly at 1919z. This anomaly resulted in the loss of two frames of SSR data. * On day 205 (Jul 24), the SSR science partitions on Ahead filled as follows: SECCHI (Part 19) reached 100% full at 1920z for 1.8 hours. The cause was the DCD anomaly and SSR pointer repositioning on DOY 203. * On day 203 (Jul 22), during the DSS-26 support for Behind, turbo decoder lock was lost briefly at 204-0120z. This anomaly resulted in the loss of one frame of SSR data. * On day 205 (Jul 24), during the DSS-26 project interface test support with behind, the beginning of track was delayed by thirty minutes while DSN installed new software. The delayed telemetry did not cause any impact and the test objectives were completed successfully. * On day 209 (Jul 28), during the DSS-54 support for Behind, turbo decoder lock was lost briefly at 1346z. This anomaly resulted in the loss of one frame of SSR data. * The average daily SSR playback volume during the week was 4.3 gigabits for Ahead, and 3.5 gigabits for Behind. Week 31 (Jul 29-Aug 4) * Autonomy release 1.1.16 was successfully loaded to EEPROM on Ahead on Tuesday, Jul 30, and will be loaded on Behind on Wednesday, Jul 31. * An engineering demo using attenuators with the STEREO beacon broadcast on Ahead is scheduled for Thursday, Aug 1 (D34). * Ahead has 9 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Jul 29 (D14), Tuesday, Jul 30 (D14), Thursday, Aug 1 (D14), and Friday, Aug 2 (D14, D43). The following passes will be carried out at 160 kbps: Wednesday, Jul 31 (D54), and Saturday, Aug 3 (D25). * Behind has 11 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Tuesday, Jul 30 (D14 at 720 kbps), and Wednesday, Jul 31 (D14). The following passes will be carried out at 160 kbps: Tuesday, Jul 30 (D55), and Sunday, Aug 4 (D55). Week 32 (Aug 5-11) * A return-to-service track for station 63 with the Behind spacecraft is scheduled for Tuesday, Aug 6. This track will be shadowing the station 55 track. * The 59th momentum dump on Ahead will be carried out at 16:30 UT on Wednesday, Aug 7. * The 54th momentum dump on Behind will be carried out at 17:00 UT on Wednesday, Aug 7. * SWAVES will be performing a flight software load on Behind on Tuesday, Aug 6, and will reboot to the new software version on Thursday, Aug 8. Backup dates for these activities are Wednesday, Aug 7, and Friday, Aug 9, respectively. This is the same flight software change that was made on Ahead some time ago. This new software will be needed by the Behind spacecraft in mid-August. * Ahead has 10 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Tuesday, Aug 6 (D14), Wednesday, Aug 7 (D14), and Sunday, Aug 11 (D63). The following passes will be carried out at 160 kbps: Thursday, Aug 8 (D54) and Saturday, Aug 10 (D45). * Behind has 11 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Thursday, Aug 8 (D14), and Sunday, Aug 11 (D63 at 720 kbps). The station 26 pass on Wednesday, Aug 7, will be carried out at 160 kbps. Week 33 (Aug 12-18) * An engineering demo using attenuators with the STEREO beacon broadcast on Behind is scheduled for Tuesday, Aug 13 (D45). * The station 25 pass for Behind on Tuesday, Aug 13, will be downlink only. * Ahead has 11 passes during the week, and overall coverage is nominal. A 70 meter pass is scheduled for Friday, Aug 16 (D14). The following passes will be carried out at 160 kbps: Tuesday, Aug 13 (D65), Saturday, Aug 17 (D65, D15), and Sunday, Aug 18 (D54). ESA New Norcia passes are scheduled for Monday and Tuesday, Aug 12, 13. * Behind has 11 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Aug 12 (D43), Thursday, Aug 15 (D63 at 720 kbps), and Friday, Aug 16 (D14). The following passes will be carried out at 160 kbps: Monday, Aug 12 (D26), Tuesday, Aug 13 (D24), Saturday, Aug 17 (D25), and Sunday, Aug 18 (D65). Week 34 (Aug 19-25) * Ahead has 9 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Tuesday, Aug 20 (D14), and Thursday, Aug 22 (D43). The following passes will be carried out at 160 kbps, all using station 54: Monday, Aug 19, Saturday, Aug 24, and Sunday, Aug 25. * Behind has 10 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Aug 19 (D43), Wednesday, Aug 21 (D63), and Thursday, Aug 22 (D14). The following passes will be carried out at 160 kbps: Tuesday, Aug 20 (D65), and Saturday, Aug 24 (D25). Week 35 (Aug 26-Sep 1) * DMZ work will be performed on Monday, Aug 26. See announcement above for details. * Ahead has 11 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Tuesday, Aug 27 (D43), Friday, Aug 30 (D63), and Sunday, Sep 1 (D63). The following passes will be carried out at 160 kbps: Tuesday, Aug 27 (D54), Wednesday, Aug 28 (D55), and Thursday, Aug 29 (D54). * Behind has 8 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Aug 26 (D63), Wednesday, Aug 28 (D63), Thursday, Aug 29 (D63), and Friday, Aug 30 (D14 at 720 kbps). The station 24 pass on Sunday, Sep 1, will be carried out at 160 kbps. Week 36 (Sep 2-8) * Monday, Sep 2, is Labor Day, which is a holiday at APL. * Ahead has 9 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Sep 2 (D63), Tuesday, Sep 3 (D63), Thursday, Sep 5 (D43), Friday, Sep 6 (D63, D43), Saturday, Sep 7 (D63), and Sunday, Sep 8 (D63). * Behind has 11 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Wednesday, Sep 4 (D63), Thursday, Sep 5 (D63, D14), and Saturday, Sep 7 (D63 at 720 kbps). Week 37 (Sep 9-15) * Ahead has 8 passes during the week, and overall coverage is short 8.2 hours, mainly between Wednesday-Thursday, Sep 11-12. 70 meter passes are scheduled for Monday, Sep 9 (D14), Tuesday, Sep 10 (D63), Friday, Sep 13 (D63), and Saturday, Sep 14 (D14). The following passes will be carried out at 160 kbps: Wednesday, Sep 11 (D26), and Saturday, Sep 14 (D65). * Behind has 9 passes during the week, and overall coverage is short 4.7 hours, mainly between Tuesday-Wednesday, Sep 10-11. 70 meter passes are scheduled for Wednesday, Sep 11, Thursday, Sep 12, Friday, Sep 13, and Saturday, Sep 14, all using station 63. The station 45 pass on Monday, Sep 9, will be carried out at 160 kbps, and the station 26 pass on Thursday, Sep 12, will be carried out at 240 kbps. Other * Station 27 will be taken down on Dec 8. Station 15 is being upgraded to replace it. STEREO already uses station 15--this change will increase the competition for this station. * The SSC reported that a problem was discovered with the distribution of the Converted Spacecraft Housekeeping files through the ftp server, since the number of files in the directory passed 10,000. This problem has now be fixed. However, to avoid this problem recurring, the suggestion has been made that this directory be reorganized into yearly subdirectories, as has already been done for most other data product directories, and asks whether this proposed change would cause any problems for the instrument teams. * The SECCHI proposal for additional telemetry for Comet ISON has been passed on to the MOC. The initial analysis shows that this proposal would require an extra 1.5 hours per day per spacecraft of DSN time for the 7 days leading up to the perihelion on Nov 28 (Thanksgiving), an extra 2.5-3 hours per day for the 3 days around perihelion, and then back to 1.5 hours/day for the following week. This works out to an extra 30 hours of DSN time per spacecraft for the entire 17 day period. However, there's quite a bit of DSN contention during this period, starting around weeks 33-34, due to events such as the LADEE launch, and it's hard to even get 3 hours per day per spacecraft of DSN time. * One option being considered for getting more DSN time during the Comet ISON encounter is to use station 15 while it's being refurbished. An S-band transmitter is being installed, and the MASER is being replaced. Use of station 15 during this period would entail the data not being committed, which includes an element of risk. If this option is taken, a test would be performed a few days before. * The SECCHI team is still considering their request for roll operations, and will report on this more next week. * A question was raised about how long before a maneuver would the IMU on Ahead be turned on. The answer was that the IMU would be turned on during the track before the maneuver. This would most likely be about 4 hours before the maneuver, but the MOC may be able to get this down to 1 hour. * The reduced IMU conops will be applied to Ahead right now. The same change will eventually be applied to Behind, but not in the near future. * It's possible that the rolls being requested by SECCHI could be done without using the IMU. If so, the roll speed would be slower, affecting the dwell time. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 31: M Jul 29 (210) T Jul 30 (211) W Jul 31 (212) T Aug 01 (213) Ahead: Engineering demo with station 34 F Aug 02 (214) S Aug 03 (215) S Aug 04 (216) ------------------------------------------------------------------------------- Scheduled activities for Week 32: M Aug 05 (217) T Aug 06 (218) Behind: Return-to-service track for D63 shadowing D55 W Aug 07 (219) Momentum dump, Ahead: 16:30 UT, Behind: 17:00 UT T Aug 08 (220) F Aug 09 (221) S Aug 10 (222) S Aug 11 (223) ------------------------------------------------------------------------------- Scheduled activities for Week 33: M Aug 12 (224) T Aug 13 (225) Behind: Station 25 pass downlink only Behind: Engineering demo with station 45 W Aug 14 (226) T Aug 15 (227) F Aug 16 (228) S Aug 17 (229) S Aug 18 (230) ------------------------------------------------------------------------------- Scheduled activities for Week 34: M Aug 19 (231) T Aug 20 (232) W Aug 21 (233) T Aug 22 (234) F Aug 23 (235) S Aug 24 (236) S Aug 25 (237) ------------------------------------------------------------------------------- Scheduled activities for Week 35: M Aug 26 (238) T Aug 27 (239) W Aug 28 (240) T Aug 29 (241) F Aug 30 (242) S Aug 31 (243) S Sep 01 (244) Notes: * DMZ maintenance, Aug 26, 20-23 UT ------------------------------------------------------------------------------- Scheduled activities for Week 36: M Sep 02 (245) Labor Day T Sep 03 (246) W Sep 04 (247) T Sep 05 (248) F Sep 06 (249) S Sep 07 (250) S Sep 08 (251) ------------------------------------------------------------------------------- Scheduled activities for Week 37: M Sep 09 (252) T Sep 10 (253) W Sep 11 (254) T Sep 12 (255) F Sep 13 (256) S Sep 14 (257) S Sep 15 (258) Notes: * Significant telemetry shortfalls are expected for both spacecraft during the week. ------------------------------------------------------------------------------- Upcoming events: 2013: * Nov 28 Both: Perihelion passage of Comet ISON http://stereo-ssc.nascom.nasa.gov/comet_ison/ * 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 * 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: * 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