STEREO Weekly Meeting Minutes for 2011-09-13 (Week 37) ANNOUNCEMENTS ------------- * The network upgrade originally scheduled for Sep 12 has been rescheduled for Sep 19. See below for details. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 36 (Sep 5-11) * On day 248 (Sep 5), during the DSS 26 support for Ahead, telemetry lock was lost intermittently beginning at 1156z through 1252z due to heavy rain at the Goldstone complex. This resulted in the loss of several minutes of SSR data. See DR# G111938 for more information. * On day 250 (Sep 7), during the DSS 54 support for Ahead, turbo decoder lock was lost intermittently beginning at 0603z through 0740z. This resulted in the loss of 11 frames of SSR data. See DR# N107590 for more information. * On day 251 (Sep 8), during the DSS 55 support for Ahead, the 240 kbps downlink rate was used for the duration of the support. The received signal power was satisfactory throughout the support. This was a test using a 34 meter station of a change to the STEREO data return CONOPs to implement a planned downlink rate step on selected tracks whose elevation is above 25 degrees for the duration of the track. This planned downlink rate step will help to maintain/increase the daily science data return with the ever increasing S/C range, by taking advantage of the increased RF margin at higher antenna elevations. Once this new CONOPs is implemented, the increased telemetry rates will show up in the weekly schedules. * On day 251 (Sep 8), the GRAIL mission launch was delayed two days with the actual launch on day 253-1308z (Sep 10). As a result, two tracks were added on day 251 to the AHEAD observatory, another was added on day 252, and two tracks were deleted on days 252 and 253. All SSR were recovered. The track coverage for the BEHIND observatory was not affected. GRAIL is a very intense mission, with two spacecraft, 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. * On day 252 (Sep 9), during the DSS 34 support for Ahead, turbo decoder lock was lost briefly beginning at 0115z. This resulted in the loss of one frame of SSR data. * On day 253 (Sep 10), during the DSS 55 support for Ahead, turbo decoder lock was lost briefly beginning at 0947z. This resulted in the loss of four frames of SSR data. A DR has been requested. * On day 254 (Sep 11), during the DSS 15 support for Ahead, turbo decoder lock was lost briefly beginning at 1730z. This resulted in the loss of 406 frames of SSR data. A DR has been requested. * On day 248 (Sep 5), during the DSS 15 support for Behind, the delivery of SSR data to the MOC was delayed 24 hours due to a DCD anomaly. All SSR data were recovered. See DR# N107588 for more information. * On day 249 (Sep 6), during the DSS 34 support for Behind, turbo decoder lock was lost briefly beginning at 0626z. This resulted in the loss of two frames of SSR data. See DR# N107584 for more information. * On day 254 (Sep 11), during the DSS 63 support for Behind, the SWAVES science partition appeared to begin overwriting at 1841z for 18 minutes due to insufficient track time. However, the SWAVES team reports that no science data were lost. * The average daily SSR playback volume was 4.7 gigabits for Ahead, and 4.5 gigabits for Behind. Week 37 (Sep 12-18) * Early this morning, during the Ahead pass on station 63, the transmitter was unavailable for part of the track. This caused a small gap when the transmitter went out, and the remainder of the track was carried out as downlink only. * The external network switch upgrade at APL originally scheduled for Monday, Sep 12 has been rescheduled for Monday, Sep 19. See below for details. * There is a gap of 17 days in coverage from southern hemisphere stations for the Ahead spacecraft starting in week 37, from days 253-270 (Sep 10-27). This will affect the accuracy of the ephemeris calculations. However, since there will be three weeks of tracking before this outage, there should be no problem with the ephemeris calculations. * 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 11 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. Week 38 (Sep 19-25) * The external network switch at APL will be upgraded on Monday, Sep 19, from 22:30-00:30 UT. This will be between tracks. Telemetry connections from the instrument teams will need to be reestablished after the upgrade. * 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 an hour short on Friday, Sep 23. 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 2-4 hours each day for Tuesday-Thursday, Sep 27-29, or 9 hours in total. Some data may be lost. Week 40 (Oct 3-9) * The 41st momentum dump on Ahead is scheduled for Tuesday, Oct 4, with ignition starting at 13:30 UT. * The 35th momentum dump on Behind is also scheduled for Tuesday, Oct 4, with ignition starting at 15:00 UT. * Ahead has 480 kbps passes on Monday, Oct 3 (D63), Tuesday, Oct 4 (D63), Thursday, Oct 6 (D14 and D43), Saturday, Oct 8 (D14), and Sunday, Oct 9 (D63). There are 12 passes during the week, and coverage is short about 1.2 hours each on both Wednesday and Thursday, Oct 5-6. There is a potential for data loss. * Behind has 480 kbps passes on Monday, Oct 3 (D63), Wednesday, Oct 5 (D14), and Sunday, Oct 9 (D14). There are 11 passes during the week, and overall coverage is nominal. Week 41 (Oct 10-16) * Ahead has 480 kbps passes on Monday, Oct 10 (D63), Thursday, Oct 13 (D14), Friday, Oct 14 (D63), Saturday, Oct 15 (D43), and Sunday, Oct 16 (D63 and D43). There are 13 passes during the week, and overall coverage is nominal. * Behind has 480 kbps passes on Tuesday, Oct 11 (D14 and D63), Wednesday, Oct 12 (D14), Saturday, Oct 15 (D43 and D14), and Sunday, Oct 16 (D43). There are 13 passes during the week, and overall coverage is short 4.5 hours on Friday, Oct 14. Week 42 (Oct 17-23) * Ahead has a 480 kbps pass on Monday, Oct 17 using station 14. There are 9 passes during the week, and overall coverage is nominal. * Behind has a 480 kbps pass on Thursday, Oct 20, using station 14. There are 13 passes during the week, and coverage is short 1.1 hours on Friday, Oct 21. Week 43 (Oct 24-30) * The 19th SECCHI stepped calibration roll will be carried out on Ahead on Wednesday, day 299 (Oct 26), starting at 08:25 UT. This will be the aphelion roll. The actual date of aphelion is day 290 (Oct 17). System momentum will be about 3 N-m-s. * Ahead has 480 kbps passes on Monday, Oct 24 (D63), Tuesday, Oct 25 (D14), and Wednesday, Oct 26 (D14). There are 10 passes during the week, and overall coverage is nominal. * Behind has a 480 kbps pass on Wednesday, Oct 26 using station 63. There are 12 passes during the week, and coverage is short 1.2 hours on Monday, Oct 24. Week 44 (Oct 31-Nov 6) * Daylight savings time is ending in the U.S. on Nov 6 at 06:00 UT. * Ahead has 480 kbps passes on Monday, Oct 31 (D14), Tuesday, Nov 1 (D14), Wednesday, Nov 2 (D63), and Saturday, Nov 5 (D43). There are 10 tracks during the week, and coverage is short 1.25 hours on Nov 6. * Behind has 480 kbps passes on Wednsday, Nov 2 (D63), and Saturday, Nov 5 (D43 and D63). There are 12 passes during the week, and coverage is short 1.4 hours between Monday and Tuesday (Oct 31-Nov 1). Other * Coordination discussions are still ongoing between the MOC and ESA on the use of ESA stations for STEREO. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- 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) ------------------------------------------------------------------------------- Scheduled activities for Week 40: M Oct 03 (276) Ahead: 480 kbps downlink on station 63 Behind: 480 kbps downlink on station 63 T Oct 04 (277) Momentum dumps, Ahead: 13:30, Behind: 15:00 Ahead: 480 kbps downlink on station 63 W Oct 05 (278) Behind: 480 kbps downlink on station 14 T Oct 06 (279) Ahead: 480 kbps downlink on stations 14 and 43 F Oct 07 (280) S Oct 08 (281) Ahead: 480 kbps downlink on station 14 S Oct 09 (282) Ahead: 480 kbps downlink on station 63 Behind: 480 kbps downlink on station 14 ------------------------------------------------------------------------------- Scheduled activities for Week 41: M Oct 10 (283) Ahead: 480 kbps downlink on station 63 T Oct 11 (284) Behind: 480 kbps downlink on stations 14 and 63 W Oct 12 (285) Behind: 480 kbps downlink on station 14 T Oct 13 (286) Ahead: 480 kbps downlink on station 14 F Oct 14 (287) Ahead: 480 kbps downlink on station 63 S Oct 15 (288) Ahead: 480 kbps downlink on station 43 Behind: 480 kbps downlink on stations 43 and 14 S Oct 16 (289) Ahead: 480 kbps downlink on stations 63 and 43 Behind: 480 kbps downlink on station 43 ------------------------------------------------------------------------------- Scheduled activities for Week 42: M Oct 17 (290) Ahead: 480 kbps downlink on station 14 T Oct 18 (291) W Oct 19 (292) T Oct 20 (293) Behind: 480 kbps downlink on station 14 F Oct 21 (294) S Oct 22 (295) S Oct 23 (296) ------------------------------------------------------------------------------- Scheduled activities for Week 43: M Oct 24 (297) Ahead: 480 kbps downlink on station 63 T Oct 25 (298) Ahead: 480 kbps downlink on station 14 W Oct 26 (299) Ahead: SECCHI stepped calibration roll, 8:25 UT Ahead: 480 kbps downlink on station 14 Behind: 480 kbps downlink on station 63 T Oct 27 (300) F Oct 28 (301) S Oct 29 (302) S Oct 30 (303) ------------------------------------------------------------------------------- Scheduled activities for Week 44: M Oct 31 (304) Ahead: 480 kbps downlink on station 14 T Nov 01 (305) Ahead: 480 kbps downlink on station 14 W Nov 02 (306) Ahead: 480 kbps downlink on station 63 Behind: 480 kbps downlink on station 63 T Nov 03 (307) F Nov 04 (308) S Nov 05 (309) Ahead: 480 kbps downlink on station 43 Behind: 480 kbps downlink on stations 43 and 63 S Nov 06 (310) Daylight savings time ends in USA ------------------------------------------------------------------------------- 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