STEREO Weekly Meeting Minutes for 2010-09-28 (Week 39) ANNOUNCEMENTS ------------- * The internet will be shut down for 10 minutes on Wednesday, Oct 6, starting at 23:30 UT. The instrument teams will lose connectivity during this time. There are no tracks during this period. * The restricted IONet at APL will be upgraded during week 41. See below for details. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 38 * MOC data was unavailable during the station 26 pass for Ahead on day 263 (Sep 20). This was traced to a network problem at Goddard. Instrument SSR telemetry was unaffected. * Turbo decoder lock was lost briefly at 03:15 UT during the return-to-service track for station 65 on Ahead on day 265 (Sep 22). This would have resulted in the loss of 5 frames of data. However, all the data were recorded using station 55 at the same time, so no data were lost. * The station 15 transmitter was red for the Ahead pass on day 265 (Sep 22) due to a problem with the cooling flow. The pass was switched to station 25, and all data were recovered. * Turbo decoder lock was lost intermittently during the station 63 pass for Ahead on day 266 (Sep 23), at 04:20, 04:55, and 05:20 UT. This resulted in the loss of 14 frames of SECCHI SSR data. * The station 25 antenna wouldn't move before the Ahead pass on day 268 (Sep 25). The antenna control was reset, and the pass resumed. This resulted in the loss of 32 minutes of realtime telemetry, and several minutes of SSR data. * Realtime telemetry and commanding was lost for 110 minutes starting at 00:30 UT during the station 24 pass for Behind on day 266 (Sep 23) due to lightning at Goddard. All SSR data were recovered. * The station 65 antenna stopped tracking during the Behind pass on day 267 (Sep 24). This resulted in the loss of 23 minutes of realtime data, and several minutes of SSR data. * The average daily SSR downlink was 6.5 gigabits for Ahead, and 5.2 gigabits for Behind. Week 39 * Command bind was lost several times during the station 54 passes for Behind both yesterday (Sep 27) and today (Sep 28). It is believed that all commands were eventually sent up successfully yesterday. Command bind has been lost three times today. The problem appears to be a network problem. * Sep 30 marks the end of the first extended mission. * Ahead has 720 kbps tracks on Monday, Sep 27, Wednesday (Sep 29), Friday (Oct 1), and Saturday (Oct 2), all using station 63 in Madrid. Overall, there are 14 tracks for Ahead during the week. * There are no 720 kbps tracks for Behind during the week. Overall, there are 12 tracks for Behind during the week. * Overall coverage is 4.5 hours over nominal for Ahead, and 4.2 hours over nominal for Behind. Week 40 * The soft command loss timer will be disabled on Friday, Oct 8, in preparation for the work being done on the restricted IONet in the following week. * There will be a return-to-service track for station 14 on Ahead on Oct. 8. This will overlap with a station 25 track. The MOC will be able to see the telemetry during the pass, but will otherwise will not use the pass. Although station 14 is a 70 meter station, the track will not be carried out at 720 kbps. * The internet will be shut down for 10 minutes on Wednesday, Oct 6, starting at 23:30 UT. The instrument teams will lose connectivity during this time. There are no tracks during this period. * There will be a SECCHI aphelion stepped calibration on Behind on Oct 8, starting at 11:15 UT. * Ahead has 720 kbps tracks on Tuesday 278 and Thursday 280. Overall, there are 14 tracks for Ahead during the week. * There are no 720 kbps tracks for Behind during the week. Overall, there are 12 tracks for Behind during the week. * Overall coverage is 6.2 hours over nominal for Ahead, and 3.0 hours over nominal for Behind. * The Behind track on Tuesday, Oct 5 has been changed from station 15 to station 24. The track duration is the same, but the start time has shifted. Similarly, the start time for the station 24 pass for Behind on Sunday, Oct 10 has also been shifted by about 15 minutes. Both changes were made to accommodate the ROSETTA mission. 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 Monday-Thursday, but it may not take that long. This may lead to problems during Ahead tracks on Oct. 11, 13, and 14. The last two hours of the track are affected on Oct 11 and 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 MOC is looking into if it is possible to send up prerecorded commands stored at the DSN. The 70 meter track will be carried out at 720 kbps, but commanding may not be available. * Commands will be sent up early during the Ahead pass on Oct 11, before the IONet goes down at 12:00 UT. Time tagged commands will also be loaded to free space on both spacecraft for Tuesday, Wednesday, and Thursday. * The 33rd momentum dump will be carried out on Ahead on Friday, Oct. 15, starting at 14:00 UT. * There will be a 720 kbps pass for Ahead on Wednesday, Oct 13. Overall, there are 13 tracks for Ahead, and the coverage is 6.0 hours over nominal. * Aphelion for Behind is Oct 16. * There will be no 720 kbps tracks for Behind this week and 10 tracks overall. Coverage is 1.3 hours 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. * There will be no 720 kbps tracks for Behind this week and 14 tracks overall. * Overall coverage is 3.25 hours over nominal for Ahead, and 1.75 hours over nominal for Behind. 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 * Daily savings time 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. Other * PLASTIC has modified their DPU software to allow specific APIDs to be turned off. This software modification must be combined with IMPACT. They are also working on extending the accumulation period on specific data products. These changes allow the PLASTIC telemetry rate to be decreased. The next drop in telemetry is in June/July 2011. * It was noted that IMPACT has recently been using the stored command buffer routinely. Previously it was mostly SWAVES who used the stored command buffer. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 39: M Sep 27 (270) Ahead: 720 kbps downlink on station 63 T Sep 28 (271) W Sep 29 (272) Ahead: 720 kbps downlink on station 63 T Sep 30 (273) End of extended mission #1 F Oct 01 (274) Ahead: 720 kbps downlink on station 63 S Oct 02 (275) Ahead: 720 kbps downlink on station 63 S Oct 03 (276) ------------------------------------------------------------------------------- Scheduled activities for Week 40: M Oct 04 (277) T Oct 05 (278) Ahead: 720 kbps downlink on station 63 W Oct 06 (279) T Oct 07 (280) Ahead: 720 kbps downlink on station 63 F Oct 08 (281) Ahead: Return-to-service track on station 14 Behind: SECCHI stepped calibration roll, 11:15 UT Both: Disable soft command loss timer S Oct 09 (282) S Oct 10 (283) ------------------------------------------------------------------------------- Scheduled activities for Week 41: M Oct 11 (284) IONet down 12-21 UT T Oct 12 (285) IONet possibly 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: 720 kbps downlink on station 14 Behind: 720 kbps downlink on station 43 S Nov 07 (311) Daily savings time ends in U.S. ------------------------------------------------------------------------------- Upcoming events: 2010: SECCHI Stepped calibration rolls Ahead: Nov 2 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