STEREO Weekly Meeting Minutes for 2010-10-12 (Week 41) ANNOUNCEMENTS ------------- * None INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 40 * The Ahead pass on station 34 started about 12 minutes late on day 277 (Oct 4) due to a procedural error. All SSR data were recovered. * On day 278 (Oct 5), DSS 25 was declared red before the start of the support for Ahead. The support was moved to DSS 15; however, the end of track was 3.25 hours early. All SSR data were recovered. See DR# G110607 for more information. * On day 279 (Oct 6), as DSS 25 was still red due to an ongoing antenna pointing anomaly, the support for Ahead was moved to DSS 15 in its entirety. All SSR data were recovered. See DR# G110620 for more information. * On day 280 (Oct 7), DSS 26 was declared red before the start of the support for Ahead. The support was moved to DSS 15; however, the BOT was 43 minutes late and the end of track was 2 hours early. This resulted in the loss of approximately six to nine hours of instrument SSR data. See DR# G110624 for more information. * On day 281 (Oct 8), as DSS 25 was still red due to an ongoing antenna pointing anomaly, AHEAD was scheduled to use the return to service track with DSS 14. However, it was red as well due to a pointing anomaly until 1401z and only tracked for 1.4 hours. During this time, the MOC did not receive any data due to a mis-configuration of the DCD. SSR pointers were repositioned during the next track and all SSR data were recovered. See DR# G110639 and N106613 for more information. * On day 282 (Oct 9), during the DSS 55 support for Ahead, telemetry lock was lost intermittently at 0335z through 0341z, and again at 0807z through 0810z due to very heavy rain. At 0826z, the uplink was lost due to transmitter alarms. This resulted in the loss of several minutes of instrument SSR data. See DR# M105987 and M105988 for more information. * On day 283 (Oct 10), during the DSS 65 support for Ahead, turbo decoder lock was lost briefly at 0511z. This resulted in the loss of several minutes of instrument SSR data. * On day 283 (Oct 10), as DSS 25 was still red due to an ongoing antenna pointing anomaly, the support for Ahead was moved to DSS 26. However, the end of track was 2.75 hours early. This is expected to cause several hours of SECCHI data loss. See DR# G110648 for more information. * On day 278 (Oct 5), during the DSS 15 support, the telemetry modulation index on Ahead was changed from 0.6 to 0.82 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. An additional adjustment will be made next week to reach NOAA's target. * On day 277 (Oct 4), during the DSS 65 support for Behind, turbo decoder lock was lost intermittently at 1516z for 14 minutes due to an antenna pointing anomaly. This resulted in the loss of 121 frames of instrument SSR data. See DR# M105978 for more information. * On day 278 (Oct 5), DSS 25 was declared red, due to a failed antenna controller, before the start of the support for Behind. As no other antennas were available, this support did not occur. However, as the SSR was nearly empty five hours before and the next track was 13 hours away, all SSR data were recovered. See DR# G110605 for more information. * On day 278 (Oct 5), during the DSS 54 support for Behind, the command bind aborted due to an exciter anomaly at 1649z and 1733z. The turbo decoder also lost lock momentarily at 1733z. This resulted in the loss of one frame of instrument SSR data. See DR# M105980 for more information. * On day 278 (Oct 5), during the DSS 24 support for Behind, the downlink was early at 0118z due to a planning software anomaly in the MOC. This MOC planning software anomaly (CR #6486) had been discovered a month ago and while a fix is being tested, it had not been deployed yet. * On day 279 (Oct 6), during the DSS 45 support for Behind, turbo decoder lock was lost intermittently at 0647z for 14 minutes due to an antenna pointing anomaly. This resulted in the loss of approximately five minutes of instrument SSR data. See DR# N106614 for more information. * Overall, Behind data recovery is okay, but Ahead has lost a significant amount of telemetry coverage. SECCHI has been losing about 1 hour per day. There is additional track time this week, so the data backlog should be caught up with by the end of the week. * The 15th SECCHI stepped calibration roll on Behind was carried out on day 281 (Oct 8), starting at 11:15 UT. This was the aphelion roll. * On day 281, during the DSS 54 support, the 60 hour soft command loss timer autonomy rule was disabled on Behind to prevent firing during the planned RIONet outage at APL. * The average daily SSR playback volume was 4.7 gigabits for Ahead, and 4.8 gigabits for Behind. Week 41 * Week 41 APL will reconfigure the restricted IONet, moving it to a new MOC in preparation for RBSP. Times blocked out for this activity are 12:00-21:00 UT Tuesday-Thursday, but it may not take that long. This may lead to problems during Ahead tracks on Oct. 13, and 14. The last two hours of the track are affected on Oct 14, while the 70 meter track on Oct 13 is during the scheduled downtime. Soft command loss timers will be disabled on both spacecraft for several days. The 70 meter track will be carried out at 720 kbps, but commanding may not be available. Time tagged commands have also been loaded to automatically free space on both spacecraft for Tuesday, Wednesday, and Thursday. * The 60 hour soft command loss timer autonomy rull was disabled on Ahead yesterday (Oct 11) to prevent firing during the planned RIONet outage at APL. * The RIONet was brought down this morning (Oct 12) as scheduled. Preliminary reports are that the reconfiguration is proceeding as planned, and they hope to complete the reconfiguration by tonight. This will be tested during a Behind pass starting at 7:10 local time this evening (23:10 UT), and during an Ahead pass at 03:40 UT tomorrow morning (Oct 13). * There will be a 720 kbps pass for Ahead on Wednesday, Oct 13, which will help free up space on the recorder. Overall, there are 13 tracks for Ahead, and the coverage is 6.0 hours over nominal. * SECCHI asked when they will be able to send up commands to the Ahead spacecraft to put up a lower cadence schedule, because of the earlier missed pass. Any commands that they send will go up tonight, starting around 4 UT. * The 33rd momentum dump will be carried out on Ahead on Friday, Oct. 15, starting at 14:00 UT. * Aphelion for Behind is Oct 16. * There will be no 720 kbps tracks for Behind this week and 10 tracks overall. Coverage is 1 hour over nominal. * Days 288-289 (Oct 15-16) there will be a 32 hour gap in coverage for Behind but we should be able to ride over it. Week 42 * The soft command loss timer will be re-enabled on Monday, Oct 18. * There will be a 720 kbps track for Ahead on Friday, Oct 22. There will be 12 tracks overall, and coverage is 3.75 hours over nominal. * There will be no 720 kbps tracks for Behind this week. There will be 14 tracks overall, and coverage is 1.75 hours over nominal. Week 43 * Oct 26 is the fourth anniversary of the launch of STEREO. * The 27th momentum dump will be carried out on Behind on Thursday Oct. 28, starting at 17:30 UT. * There will be a 720 kbps track for Ahead on Wednesday, Oct 27. There will be 14 tracks overall, and coverage will be 2.5 hours over nominal. * There will be 720 kbps tracks for Behind on Monday and Tuesday, Oct 25-26. There will be 12 tracks for Behind overall, and coverage will be 1.6 hours over nominal. 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. There are 14 passes overall, and coverage is 1.25 hours over nominal. * Behind will have a 720 kbps pass on Saturday, Nov 6. There are 14 passes overall, and coverage is 4.3 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, Thursday, Nov 11, and Saturday, Nov 13. There are 14 passes during the week, and overall coverage is 4 hours above nominal. * There are no 720 kbps passes for Behind during the week. There are 12 passes during the week, and overall coverage is 4.4 hours below nominal. In particular, coverage is short on Monday, Tuesday, and Wednesday (Nov 8-10). There should be no loss of in situ data. Week 46 * Ahead has 720 kbps passes on Monday, Nov 15, and Friday, Nov 19. There are 14 tracks during the week, and overall coverage is nominal. * Behind has 720 kbps passes on Monday, Nov 15, and Sunday, Nov 21. There are 13 tracks during the week, and overall coverage is 5.3 hours below nominal. In particular, coverage on Wednesday, Nov 17 is 3.2 hours short. There should be no loss of in situ data. Other * There are currently a number of contentions for the Behind spacecraft. In the winter, this will switch to the Ahead spacecraft. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 41: M Oct 11 (284) T Oct 12 (285) IONet down 12-21 UT W Oct 13 (286) IONet possibly down 12-21 UT, Ahead: 720 kbps downlink on station 43 T Oct 14 (287) IONet possibly down 12-21 UT F Oct 15 (288) Ahead: Momentum dump, 14:00 UT S Oct 16 (289) Behind: Aphelion S Oct 17 (290) ------------------------------------------------------------------------------- Scheduled activities for Week 42: M Oct 18 (291) Both: Re-enable soft command loss timer T Oct 19 (292) W Oct 20 (293) T Oct 21 (294) F Oct 22 (295) Ahead: 720 kbps downlink on station 63 S Oct 23 (296) S Oct 24 (297) ------------------------------------------------------------------------------- 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 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) Ahead: 720 kbps downlink on station 14 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 ------------------------------------------------------------------------------- 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