STEREO Weekly Meeting Minutes for 2013-08-13 (Week 33) ANNOUNCEMENTS ------------- * The SECCHI team has distributed a proposal for spacecraft rolls to observe Comet ISON. The details of this proposal are in a separate e-mail, but some discussion can be found below. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 32 (Aug 5-11) * On day 219 (Aug 7), the SECCHI instrument on Ahead reset at 09:32:09z. The SECCHI team reconfigured the instrument to operational mode at 1608z. This was the 31st reset of SECCHI on the Ahead spacecraft. * On day 219 (Aug 7), the 59th momentum dump on Ahead was executed successfully at 1630Z, which imparted a delta V of 0.0969 m/sec. * On day 219 (Aug 7), during the DSS-65 support for Behind, turbo decoder lock was lost intermittently beginning at 1454z through 1748z. This anomaly resulted in the loss of six frames of SSR data. See DR #M107452 for more information. * On day 221 (Aug 9), during the DSS-65 support for Behind, turbo decoder lock was lost intermittently beginning at 0951z through 1101z. This anomaly resulted in the loss of 15 frames of SSR data. See DR #M107457 for more information. * On day 223 (Aug 11), during the DSS-63 support for Behind, the receiver and ranging processor unexpectedly went out of lock between 1507z through 1625z. Also during this track, turbo decoder lock was lost intermittently beginning at 1424z through 1625z. These anomalies resulted in the loss of 11670 frames of SSR data. See DR #M107463 for more information. * On day 219 (Aug 7), the 54th momentum dump on Behind was executed successfully at 1700Z, which imparted a delta V of 0.066 m/sec. * On day 220, SWAVES successfully loaded flight software version 4.12. This will be activated later this week. * The average daily SSR playback volume during the week was 3.6 gigabits for Ahead, and 3.3 gigabits for Behind. * Station 63 come back up after its recent maintenance, but the problem with receiver and ranging processor going unexpectedly out of lock still persists. This recent problem was not on the maintenance schedule. The DSN is still looking into the problem, and trying to determine what the problem is. Week 33 (Aug 12-18) * Turbo lock was lost briefly during the station 34 pass for Ahead early yesterday (Aug 12) due to heavy rain at the Canberra station. * Turbo lock was lost briefly during the station 24 pass for Ahead yesterday (Aug 12). * An engineering demo using attenuators with the STEREO beacon broadcast on Behind with station 45 was carried out this morning (Aug 13). * The station 25 pass for Behind tonight (Aug 13) will be downlink only. * SWAVES will be activating their flight software update on Behind on Thusday, Aug 15, during the station 63 pass. * 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 is planned for Monday, Aug 26, between 20-23 UT. This will require several reboots, and instrument teams can expect to need to reconnect. However, other missions have seen significant impact from the proposed changes, and the work may be rescheduled. * 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), Saturday, Sep 7 (D63 at 720 kbps), and Sunday, Sep 8 (D63). The following passes will be carried out at 160 kbps: Monday, Sep 2 (D45), and Friday, Sep 6 (D55, D24). Week 37 (Sep 9-15) * Momentum dumps are expected to be scheduled during this week. * Ahead has 10 passes during the week, and overall coverage is nominal. 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). ESA New Norcia passes are scheduled for Wednesday, Sep 11, and Thursday, Sep 12. * Behind has 9 passes during the week, and overall coverage is nominal. 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. Week 38 (Sep 16-22) * Ahead has 7 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Sep 16 (D43), Tuesday, Sep 17 (D63), Thursday, Sep 19 (D14), Friday, Sep 20 (D63), and Saturday, Sep 21 (D63 at 720 kbps). The station 65 pass on Wednesday, Sep 18, will be carried out at 160 kbps. * Behind has 11 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Sep 16 (D63 at 720 kbps), Tuesday, Sep 17 (D63 at 720 kbps), Wednesday, Sep 18 (D63), Thursday, Sep 19 (D63), Friday, Sep 20 (D43), and Saturday, Sep 21 (D63). Other * Testing has been continuing on the "flatsat" for reduced gyro operations. The G&C team also has its own simulator. The Go/No-go review for the Ahead reduced gyro operations is now Sep 12 at APL. Once the reduced gyro mode has been in use on the Ahead spacecraft for a while, the instrument teams will be asked to report any impacts on their scientific data. No impacts are expected, since the spacecraft attitude really depends on the guide telescope and the star tracker. Once the change on Ahead has been determined to be successful, the same change will be applied to Behind. * The laser gyros do not give the roll attitude directly, they only give the rate of roll. * SECCHI has distributed a proposal for roll operations to observe Comet ISON. Feedback on this proposal is requested from the other instrument teams and the MOC. So far the in situ teams report that they are willing to go along with the proposal because of the unique science opportunity this represents. However, the IMPACT team is still discussing this among themselves, since some instruments will no longer be pointed along the Parker spiral. PLASTIC reports that the rolls can be useful for calibration. Fine pointing will be lost between the roll positions, but coarse pointing will be maintained. Extra momentum dumps will probably be needed to keep the system within safe bounds for roll operations. The SECCHI team requests that no momentum dumps be scheduled during the approximately two weeks around perihelion. During the periods when spacecraft are being rolled for three days a week, it is requested that these be three days in a row. Nominally, there would then be a four day period before the next roll, but this period is flexible. When both spacecraft are rolled, it is requested that the rolls be simultaneous if possible. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- 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) ------------------------------------------------------------------------------- Scheduled activities for Week 38: M Sep 16 (259) T Sep 17 (260) W Sep 18 (261) T Sep 19 (262) F Sep 20 (263) S Sep 21 (264) S Sep 22 (265) ------------------------------------------------------------------------------- Upcoming events: 2013: * Oct 10-Nov 23 Ahead: Comet ISON in HI2 field-of-view * Nov 21-28 Ahead: Comet ISON in HI1 field-of-view * Nov 28 Both: Perihelion passage of Comet ISON http://stereo-ssc.nascom.nasa.gov/comet_ison/ * Dec 1-7 Ahead: Comet ISON in HI1 field-of-view * 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