STEREO Weekly Meeting Minutes for 2010-11-02 (Week 44) ANNOUNCEMENTS ------------- * The STEREO Science Center will be moving from building 26 at Goddard to building 21. The date isn't known yet, but is now expected to be sometime before Thanksgiving, possibly during the week of Nov 15. The SSC will be offline for 2-3 days during the move. Science products will still be available at APL. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 43 * On day 298 (Oct 25), during the DSS 25 support for Ahead, the antenna was stowed at 1237z due to high winds in excess of 50 MPH. The antenna was on point at 1332z after the high wind condition subsided. SSR pointers were repositioned and all SSR data was recovered. See DR# G110714 for more information. * On day 302 (Oct 29), during the DSS 26 support for Ahead, turbo decoder lock was lost briefly at 1320z. This resulted in the loss of two frames of instrument SSR data. A DR has been requested. * On day 303 (Oct 30), during the DSS 45 support for Ahead, turbo decoder lock was lost intermittently at 1959z for 28 minutes due to heavy rain at Canberra. This resulted in the loss of two hours of instrument SSR data. See DR# C107700 for more information. * Day 299 (Oct 26) was the fourth anniversary of the launch of STEREO. * On day 298 (Oct 25), during the DSS 15 support for Behind, turbo decoder lock was lost intermittently at 0200z and again at 0223z. This resulted in the loss of several minutes of instrument SSR data. See DR# N106677 for more information. * On day 303 (Oct 30), during the DSS 55 support for Behind, the uplink was delayed 25 minutes due to a failed power supply. The uplink was established at 1426z. This resulted in the loss of several minutes of instrument SSR data. See DR# M106024 for more information. * On day 300 (Oct 27), during the DSS 54 support for Behind, the telemetry modulation index was changed from 0.6 to 0.83 radians in C&DH RAM for the space weather broadcast only. This was done to lengthen the use of the space weather signal reception at the NOAA stations. The same change has already been performed on Ahead. * The 27th momentum dump was successfully carried out on Behind on day 301 (Oct 28), starting at 17:30 UT. A delta V of 0.0681 m/sec was imparted. * The average daily SSR downlink was 5.0 gigabits for Ahead, and 4.9 gigabits for Behind. * The checksum error on the IMPACT/PLASTIC DPU on Behind was corrected. This error was due to a flipped bit in an area of code used for changing voltage settings, and was not actively being used at the time of the error. The instrument team would know from the checksum monitor if there was a problem in this area of code before executing voltage settings. This is the second time that a bit has been flipped on Behind in this area of code. * On day 301 (Oct 28), SECCHI changed the memory timing bit in RAM for the Behind spacecraft. This is the change intended to correct the problem with watchdog resets. The same change has already been applied on Ahead. Week 44 * Ahead will be at aphelion on Nov 6. * Daily savings time in the U.S. ends Nov 7. * Ahead will have 720 kbps tracks on Wednesday, Nov 3, and Saturday, Nov 6, using station 14. There are 14 passes overall, and coverage is 1.25 hours over nominal. * No spacecraft SSR telemetry will be downlinked during short Ahead passes on Monday, Nov 8, Tuesday, Nov 9, and Thursday, Nov 11. * Since station 14 has only recently come back online after a long hiatus, there may be issues with the signal level at low elevations for the next few weeks. DSN suggests delaying any SSR dumps until an elevation of 20 degrees is reached. These times will be computed and passed along to the MOC. * A DCD test with the DSN was carried out for Behind on Monday, Nov 1. There were some minor issues involving file protection and ftp access which the MOC is working out with the DSN, but otherwise the test went fine. * Behind will have a 720 kbps pass on Saturday, Nov 6 using station 43. There are 15 passes overall, and coverage is 3.6 hours over nominal. Week 45 * The 15th SECCHI stepped calibration roll will be carried out on Ahead on Tuesday, Nov 9, starting at 08:30 UT. This is the aphelion roll. The system momentum will be about 1 N-m-s. * Ahead has 720 kbps passes on Tuesday, Nov 9, using station 14, and Saturday, Nov 13, using station 63. There are 14 passes during the week, and overall coverage is 4 hours above nominal. * MOPS software version 1.1.7 will be loaded to EEPROM on both Ahead and Behind. This version is currently running in RAM without problems. * Behind will use the new DCD system for the station 55 pass on Monday, Nov 8. All Madrid passes will use DCD from now on. * There are no 720 kbps passes for Behind during the week. There are 12 passes during the week, and overall coverage is 1.6 hours below nominal. This is an improvement over what was reported the previous week, mainly due to increased track time on Thursday, Nov 11. Week 46 * Ahead has 720 kbps passes on Monday, Nov 15, and Friday, Nov 19, both using station 14. There are 14 tracks during the week, and overall coverage is nominal. * Behind has 720 kbps passes on Monday, Nov 15, using station 43, and Sunday, Nov 21, using station 14. There are 13 tracks during the week, and overall coverage is 3.3 hours below nominal. Week 47 * Ahead has 720 kbps passes on Tuesday, Nov 24, using station 63, and Sunday, Nov 28, using station 14. There are 14 tracks during the week, and overall coverage is nominal. * Behind has 720 kbps passes on Monday, Nov 23, using station 63, and Friday, Nov 26, using station 14. There are 14 tracks during the week, and overall coverage is nominal. * Thursday, Nov 25 is Thanksgiving in US. Friday, Nov 26 is also a holiday at APL. The MOC will be operating unattended both days. Week 48 * Ahead has 720 kbps passes on Monday, Nov 29, Wednesday, Dec 1, Thursday, Dec 2, and Saturday, Dec 4. The Monday pass uses station 14; the rest use station 63. There are 14 tracks during the week, and overall coverage is nominal. * The 34th momentum dump on Ahead will be carried out Thursday, Dec 2, with ignition at 15:00 UT. * Behind has a 720 kbps pass on Sunday, Dec 5, using station 63. There are 12 tracks during the week, and overall coverage is 3.5 hours below nominal. Other * The SSC noted a problem with some attitude history files for Ahead being created with zero file sizes. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 43: M Oct 25 (298) Behind: 720 kbps downlink on station 43 T Oct 26 (299) Behind: 720 kbps downlink on station 43 Fourth anniversary of STEREO's launch W Oct 27 (300) Ahead: 720 kbps downlink on station 63 Behind: Change modulation index for beacon telemetry T Oct 28 (301) Behind: Momentum dump, 17:30 UT F Oct 29 (302) S Oct 30 (303) S Oct 31 (304) ------------------------------------------------------------------------------- Scheduled activities for Week 44: M Nov 01 (305) T Nov 02 (306) W Nov 03 (307) Ahead: 720 kbps downlink on station 14 T Nov 04 (308) F Nov 05 (309) S Nov 06 (310) Ahead: Aphelion Ahead: 720 kbps downlink on station 14 Behind: 720 kbps downlink on station 43 S Nov 07 (311) Daily savings time ends in U.S. ------------------------------------------------------------------------------- Scheduled activities for Week 45: M Nov 08 (312) T Nov 09 (313) Ahead: SECCHI stepped calibration roll, 08:30 UT Ahead: 720 kbps downlink on station 14 W Nov 10 (314) T Nov 11 (315) F Nov 12 (316) S Nov 13 (317) Ahead: 720 kbps downlink on station 63 S Nov 14 (318) ------------------------------------------------------------------------------- Scheduled activities for Week 46: M Nov 15 (319) Ahead: 720 kbps downlink on station 14 Behind: 720 kbps downlink on station 43 T Nov 16 (320) W Nov 17 (321) T Nov 18 (322) F Nov 19 (323) Ahead: 720 kbps downlink on station 14 S Nov 20 (324) S Nov 21 (325) Behind: 720 kbps downlink on station 14 ------------------------------------------------------------------------------- Scheduled activities for Week 47: M Nov 22 (326) Behind: 720 kbps downlink on station 63 T Nov 23 (327) Ahead: 720 kbps downlink on station 63 W Nov 24 (328) T Nov 25 (329) US Thanksgiving F Nov 26 (330) Behind: 720 kbps downlink on station 14 S Nov 27 (331) S Nov 28 (332) Ahead: 720 kbps downlink on station 14 Notes: * APL closed both Nov 25 and Nov 26 ------------------------------------------------------------------------------- Scheduled activities for Week 48: M Nov 29 (333) Ahead: 720 kbps downlink on station 14 T Nov 30 (334) W Dec 01 (335) Ahead: 720 kbps downlink on station 63 T Dec 02 (336) Ahead: 720 kbps downlink on station 63 F Dec 03 (337) S Dec 04 (338) Ahead: 720 kbps downlink on station 63 S Dec 05 (339) Behind: 720 kbps downlink on station 63 ------------------------------------------------------------------------------- Upcoming events: 2011: * Jan 12 Both: HGA calibration * Feb 6 STEREO spacecraft at 180 degree separation * Jun 27 Ahead: Switch downlink rate to 160 kbps * Jun 27 Ahead: End use of 720 kbps on 70 m DSN subnet * Jul 15 Behind: Switch downlink rate to 160 kbps * Jul 15 Behind: End use of 720 kbps on 70 m DSN subnet * Mar 18 Messenger - Mercury orbital insertion * Jul DAWN - Vesta arrival * Jul 13 Both: HGA calibration 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