STEREO Weekly Meeting Minutes for 2011-08-09 (Week 32) ANNOUNCEMENTS ------------- * Rolls to observe comet Elenin from STEREO Behind continue through Friday. See below for details. * The master equatorial servo interface for station 14 is currently red. This may affect passes on both spacecraft for the next week or two. See below for details. * Network upgrades at APL on Sep 17 will affect paging and realtime telemetry links. See below for details. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 31 (Aug 1-7) * On day 218 (Aug 6), during the DSS 24 support for Ahead, turbo decoder lock was lost briefly beginning at 1703z. This resulted in the loss of one frame of SSR data. * On day 213 (Aug 1), the first of twelve daily SECCHI HI 135 degree roll events to observe Comet Elenin was executed successfully at 0800z on the BEHIND observatory. The rolls are between 8-10 UT each day, except for Aug 5 and Aug 12, when the rolls are between 10-12 UT. * On day 215 (Aug 3), during the DSS 55 support for Behind, the IMPACT SSR partition 15 was full at the beginning of track. This resulted in the loss of three hours of IMPACT science data from 215-1422z through 1722z. This occurred because the patch to disable STE-U telemetry was not uploaded after the recent IMPACT soft reset. The patch was reloaded over the weekend, and this problem should not reoccur. * The average daily SSR downlink volume was 4.8 gigabits for Ahead, and 4.3 gigabits for Behind. Week 32 (Aug 8-14) * Turbo decoder lock was lost briefly yesterday (Aug 8) during the Ahead track on station 26. This resulted in the loss of seven frames of data. * The 135 degree rolls on Behind to observe comet Elenin will continue through Aug 12. The rolls will be between 8-10 UT each day, except for Aug 12, when the roll will be between 10-12 UT. * The master equatorial servo interface for station 14 is currently red. This presents a problem tracking the satellite below 20 degrees elevation. This problem is hoped to be corrected by the end of the week, but may persist until Aug 19. The upcoming support for Ahead on Thursday should be higher in elevation, but there are many station 14 supports coming up after that for both spacecraft, many of them starting soon after the spacecraft rise over the horizon. * SECCHI asks whether the weekly schedules will be updated to take the station 14 problems into account. The MOC is looking into this. Depending on the result, SECCHI may need to adjust their observing schedules. * Ahead has 480 kbps passes on Thursday, Aug 11 (D14), Friday, Aug 12 (D14), Saturday, Aug 13 (D63), and Sunday, Aug 14 (D14). There are 10 passes during the week, and overall coverage is nominal. * Behind has 480 kbps passes on Tuesday, Aug 9 (D14 and D63), and Thursday, Aug 11 (D63). There are 14 passes during the week, and overall coverage is nominal. Week 33 (Aug 15-21) * The MOC network will be refreshed between 15-23 UT on Monday, Aug 15. This will be between passes, and will not affect operations. * The external network switch at APL will be upgraded on Wednesday, Aug 17, from 03:45-05:45 UT. This will also be between tracks. * Ahead has 480 kbps passes on Monday, Aug 15 (D63), Tuesday, Aug 16 (D14), Wednesday, Aug 17 (D14), Thursday, Aug 18 (D14), and Friday, Aug 19 (D14) There are 8 passes during the week, and overall coverage is nominal. * Behind has 480 kbps passes on Wednesday, Aug 17, twice on Friday, Aug 19, and Sunday, Aug 21, all using station 14. There are 15 passes during the week, and overall coverage is 8.1 hours above nominal. Week 34 (Aug 22-28) * The 40th momentum dump on Ahead is scheduled for Wednesday, Aug 24, starting at 15:00 UT. * The 34th momentum dump on Behind is also scheduled for Wednesday, Aug 24, starting at 18:00 UT. * Ahead has 480 kbps passes on Monday, Aug 22 (D63), Wednesday, Aug 24 (D14), Friday, Aug 26 (D63), Saturday, Aug 27 (D14), and Sunday, Aug 28 (D14). There are 11 passes during the week, and overall coverage is nominal. * Behind has a 480 kbps pass on Monday, Aug 22 using station 43. There are 14 passes during the week, and overall coverage is 5.6 hours above nominal. Week 35 (Aug 29-Sep 4) * Ahead has 480 kbps passes on Monday, Aug 29 (D63), Tuesday, Aug 30 (D14), Wednesday, Aug 31 (D63), Thursday, Sep 1 (D14), Friday, Sep 2 (D14), and Sunday, Sep 4 (D14). There are 11 passes during the week, and overall coverage is nominal. * Behind has 480 kbps passes on Monday, Aug 29 (D43), Wednesday, Aug 31 (D14), and Thursday, Sep 1 (D63). There are 14 passes during the week, and overall coverage is 4.6 hours above nominal. Week 36 (Sep 5-11) * Monday, Sep 5 is Labor Day. APL will be closed for the holiday. * Thursday, Sep 8, at 12:37 UT is the opening of the launch window for the GRAIL mission. This is a very intense mission, lasting just 9 months, and will require a lot of track time. This will affect the DSN scheduling for STEREO. Each spacecraft will share the view direction with GRAIL two weeks out of every month. The project is looking into getting support from ESA stations to cover the shortfall. Contingency planning in case of a launch slip is ongoing. * Ahead has 480 kbps passes on Tuesday, Sep 6 (D14), Thursday, Sep 8 (D43), Friday, Sep 9 (D63 and D14), and Saturday, Sep 10 (D43). There are 11 tracks during the week, and overall coverage is nominal. * Behind has 480 kbps passes on Monday, Sep 5 (D43), Wednesday, Sep 7 (D43), and Saturday, Sep 10 (D63). There are 14 tracks during the week, and overall coverage is nominal. Week 37 (Sep 12-18) * APL network upgrades will occur Sep 17, between 12 A.M. and 12 P.M local time. This will involve swapping switches and additional layers of protection. Paging will not be available during this period, and instrument teams can expect to lose realtime telemetry links periodically. Commanding is on a separate network, and will be unaffected. * Ahead has 480 kbps passes on Monday, Sep 12 (D14), Tuesday, Sep 13 (D63), Wednesday, Sep 14 (D14), Thursday, Sep 15 (D63), Friday, Sep 16 (D63), and Saturday, Sep 17 (D63). There are 10 passes during the week, and overall coverage is nominal. * Behind has 480 kbps passes on Monday, Sep 12 (D43 and D63), Tuesday, Sep 13 (D63), Wednesday, Sep 14 (D63), Thursday, Sep 15 (D63), Friday, Sep 16 (D43 and D63), Saturday, Sep 17 (D14), and Sunday, Sep 18 (D63). There are 10 passes during the week, and overall coverage is nominal. * There is a gap of 17 days in coverage from southern hemisphere stations for the Ahead spacecraft starting in week 37. This will affect the accuracy of the ephemeris calculations. Use of the ESA New Norcia station would mitigate this problem. However, since there will be three weeks of tracking before this outage, there should be no problem with the ephemeris calculations. Week 38 (Sep 19-25) * Ahead has 480 kbps passes on Thursday, Sep 22 (D14), and Friday, Sep 23 (D63). There are 9 passes during the week, and overall coverage is nominal. * Behind has 480 kbps passes on Monday, Sep 19 (D63), Tuesday, Sep 20 (D63), Wednesday, Sep 21 (D63), Thursday, Sep 22 (D63), Friday, Sep 23 (D63), Saturday, Sep 24 (D43 and D63), and Sunday, Sep 25 (D63). However, many of these 70 meter passes are short. There are 11 passes during the week. Coverage is about two hours short on Thursday, Sep 22, and this may be close for the in situ instruments. Week 39 (Sep 26 - Oct 2) * Ahead has 480 kbps passes on Tuesday, Sep 27 (D14 and D43), Wednesday, Sep 28 (D14), and Thursday, Sep 29 (D14). There are 11 passes during the week. Coverage is about 1.6 hours short on Monday, Sep 26. * Behind has 480 kbps passes on Tuesday, Sep 27 (D14), Wednesday, Sep 28 (D14), Friday, Sep 30 (D63), and Saturday, Oct 1 (D63). There are 9 passes during the week, and coverage is short about two hours each day for Tuesday-Thursday, Sep 27-29. Other * Cros support from the ESA 35 meter antennas in Spain and Australia are being sought to mitigate the scheduling problems associated with the GRAIL mission. * Due to a number of different missions, demand for DSN time is expected to be high through August 2012. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 32: M Aug 08 (220) Behind: 135 degree roll to observe comet Elenin, 8-10 UT T Aug 09 (221) Behind: 135 degree roll to observe comet Elenin, 8-10 UT Behind: 480 kbps downlink on stations 14 and 63 W Aug 10 (222) Behind: 135 degree roll to observe comet Elenin, 8-10 UT T Aug 11 (223) Behind: 135 degree roll to observe comet Elenin, 8-10 UT Ahead: 480 kbps downlink on station 14 Behind: 480 kbps downlink on station 63 F Aug 12 (224) Behind: 135 degree roll to observe comet Elenin, 10-12 UT Ahead: 480 kbps downlink on station 14 S Aug 13 (225) Ahead: 480 kbps downlink on station 63 S Aug 14 (226) Ahead: 480 kbps downlink on station 14 Notes * Aug 1-12 Behind: Spacecraft rolls to observe comet Elenin ------------------------------------------------------------------------------- Scheduled activities for Week 33: M Aug 15 (227) Ahead: 480 kbps downlink on station 63 T Aug 16 (228) Ahead: 480 kbps downlink on station 14 W Aug 17 (229) Ahead: 480 kbps downlink on station 14 Behind: 480 kbps downlink on station 14 T Aug 18 (230) Ahead: 480 kbps downlink on station 14 F Aug 19 (231) Ahead: 480 kbps downlink on station 14 Behind: 480 kbps downlink on station 14 (twice) S Aug 20 (232) S Aug 21 (233) Behind: 480 kbps downlink on station 14 ------------------------------------------------------------------------------- Scheduled activities for Week 34: M Aug 22 (234) Ahead: 480 kbps downlink on station 63 Behind: 480 kbps downlink on station 43 T Aug 23 (235) W Aug 24 (236) Momentum dumps, Ahead: 15:00 UT, Behind: 18:00 UT Ahead: 480 kbps downlink on station 14 T Aug 25 (237) F Aug 26 (238) Ahead: 480 kbps downlink on station 63 S Aug 27 (239) Ahead: 480 kbps downlink on station 14 S Aug 28 (240) Ahead: 480 kbps downlink on station 14 ------------------------------------------------------------------------------- Scheduled activities for Week 35: M Aug 29 (241) Ahead: 480 kbps downlink on station 63 Behind: 480 kbps downlink on station 43 T Aug 30 (242) Ahead: 480 kbps downlink on station 14 W Aug 31 (243) Ahead: 480 kbps downlink on station 63 Behind: 480 kbps downlink on station 14 T Sep 01 (244) Ahead: 480 kbps downlink on station 14 Behind: 480 kbps downlink on station 63 F Sep 02 (245) Ahead: 480 kbps downlink on station 14 S Sep 03 (246) S Sep 04 (247) Ahead: 480 kbps downlink on station 14 ------------------------------------------------------------------------------- Scheduled activities for Week 36: M Sep 05 (248) Behind: 480 kbps downlink on station 43 T Sep 06 (249) Ahead: 480 kbps downlink on station 14 W Sep 07 (250) Behind: 480 kbps downlink on station 43 T Sep 08 (251) Ahead: 480 kbps downlink on station 43 F Sep 09 (252) Ahead: 480 kbps downlink on stations 63 and 14 S Sep 10 (253) Ahead: 480 kbps downlink on station 43 Behind: 480 kbps downlink on station 63 S Sep 11 (254) ------------------------------------------------------------------------------- Scheduled activities for Week 37: M Sep 12 (255) Ahead: 480 kbps downlink on station 14 Behind: 480 kbps downlink on stations 43 and 63 T Sep 13 (256) Ahead: 480 kbps downlink on station 63 Behind: 480 kbps downlink on station 63 W Sep 14 (257) Ahead: 480 kbps downlink on station 14 Behind: 480 kbps downlink on station 63 T Sep 15 (258) Ahead: 480 kbps downlink on station 63 Behind: 480 kbps downlink on station 63 F Sep 16 (259) Behind: 480 kbps downlink on stations 43 and 63 S Sep 17 (260) Ahead: 480 kbps downlink on station 63 Behind: 480 kbps downlink on station 14 S Sep 18 (261) Behind: 480 kbps downlink on station 63 ------------------------------------------------------------------------------- Scheduled activities for Week 38: M Sep 19 (262) Behind: 480 kbps downlink on station 63 T Sep 20 (263) Behind: 480 kbps downlink on station 63 W Sep 21 (264) Behind: 480 kbps downlink on station 63 T Sep 22 (265) Ahead: 480 kbps downlink on station 14 Behind: 480 kbps downlink on station 63 F Sep 23 (266) Ahead: 480 kbps downlink on station 63 Behind: 480 kbps downlink on station 63 S Sep 24 (267) Behind: 480 kbps downlink on stations 43 and 63 S Sep 25 (268) Behind: 480 kbps downlink on station 63 ------------------------------------------------------------------------------- Scheduled activities for Week 39: M Sep 26 (269) T Sep 27 (270) Ahead: 480 kbps downlink on stations 14 and 43 Behind: 480 kbps downlink on station 14 W Sep 28 (271) Ahead: 480 kbps downlink on station 14 Behind: 480 kbps downlink on station 14 T Sep 29 (272) Ahead: 480 kbps downlink on station 14 F Sep 30 (273) Behind: 480 kbps downlink on station 63 S Oct 01 (274) Behind: 480 kbps downlink on station 63 S Oct 02 (275) ------------------------------------------------------------------------------- Upcoming events: 2012: * Jan 11 Both: HGA calibration * Jul DAWN - Vesta departure * Jul 11 Both: HGA calibration * Nov 4 Behind: Switch downlink rate to 120 kbps * Nov 13 Total solar eclipse, south Pacific 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 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