STEREO Weekly Meeting Minutes for 2011-09-06 (Week 36) ANNOUNCEMENTS ------------- * NASA headquarters has approved ESA support for the STEREO mission. The MOC will have a telecon tomorrow (Sep 7) with ESA to work out the details. Use of ESA stations can fill in gaps in the STEREO schedule due to conflicts with other missions. The ESA station in Australis could also mitigate the 17 day gap in southern hemisphere coverage for Ahead. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 35 (Aug 29-Sep 4) * On day 241 (Aug 29), during the DSS 63 support for Ahead, turbo decoder lock was lost briefly beginning at 0750z and again at 0925z. This resulted in the loss of seven frames of SSR data. See DR# N107567 for more information. * On day 244 (Sep 1), during the DSS 65 support for Ahead, monitor data was lost briefly for three minutes beginning at 0431z. All SSR data were recovered. See DR# N107580 for more information. * On day 244 (Sep 1), for the DSS 14 support for Ahead, the transmitter was declared red prior to the track due to a power supply problem. The support remained downlink only for its entirety. This anomaly resulted in the loss of all commanding and two-way tracking data for the duration of the support. All SSR data were recovered. See DR# G111928 for more information. * On day 241 (Aug 29), during the DSS 43 support for Behind, the 720 kbps downlink rate was used for the duration of the support. The received signal power was satisfactory throughout the support, in fact better than expected. This was a test 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 maintin/increase the daily science data return with the ever increasing S/C range, to take advantage of the increased RF margin at higher antenna elevations. * On day 242 (Aug 30), during the DSS 55 support for Behind, turbo decoder lock was lost briefly beginning at 1409z. This resulted in the loss of two frames of SSR data. See DR# N107569 for more information. * On day 244 (Sep 1), during the DSS 63 support for Behind, turbo decoder lock was lost briefly beginning at 1150z and again at 1344z. This resulted in the loss of 35 frames of SSR data. See DR# N107578 for more information. * On day 245 (Sep 2), during the DSS 34 support for Behind, turbo decoder lock was lost briefly beginning at 0801z. This resulted in the loss of two frames of SSR data. See DR# N107579 for more information. * The average daily SSR playback volume was 5.3 gigabits on Ahead, and 5.3 gigabits on Behind. * A DCD anomaly caused the loss of several hours of Behind data on day 238 (Aug 26). It was determined that these data could not be recovered. Week 36 (Sep 5-11) * Telemetry lock was lost at 20:56 UT during the station 26 pass for Ahead yesterday (Sep 5) due to heavy rain. * Turbo decoder lock was lost briefly at 06:26 UT this morning (Sep 6) during the station 34 pass for Behind. * A test of the 240 kbps telemetry rate for passes above 25 degrees on 34 meter stations will be carried out using station 55 for Ahead on Thursday, Sep 8. * Thursday, Sep 8, at 12:37 UT is the opening of the launch window for the GRAIL mission. This 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. * Contingency planning has been done in case of a launch slip of the GRAIL mission. Behind will not be affected unless launch slips to Sunday, Sep 11 or beyond. However, Ahead could lose quite a bit of telemetry time in case of a launch slip. Contingency passes for the Ahead spacecraft using stations 14 and 34 on Thursday, Sep 8 will be added to the schedule. If these passes are not used, then the pointers will be moved back during the following pass. The SECCHI team needs to be aware that not all of the passes that appear on the schedule will actually occur. * 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 12 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) * The external network switch at APL will be upgraded on Monday, Sep 12, from 22-24 UT. This will be between tracks. Telemetry connections from the instrument teams will need to be reestablished after the upgrade. * 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) * Ahead has 480 kbps passes on Thursday, Sep 22 (D14), and Friday, Sep 23 (D63). There are 11 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, 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 9 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). COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- 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 Ahead: 240 kbps downlink on station 55 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) ------------------------------------------------------------------------------- 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