STEREO Weekly Meeting Minutes for 2011-07-19 (Week 29) ANNOUNCEMENTS ------------- * None. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 28 (Jul 11-17) * On day 192 (Jul 11), during the DSS 15 support for Ahead, ranging was not available for the entire track due to an Uplink Ranging Assembly problem. See DR# G111791 for more information. * On day 192 (Jul 11), for the DSS 34 support for Ahead, the antenna was declared red prior to the track due to a cable wrap switch problem. The entire support was lost. To prevent data loss, the SSR Read pointers were moved back during the next track on day 193 (DSS-26). This anomaly resulted in the loss of 12-17 hours of SSR data for IMPACT and SWAVES on day 191/192 (Jul 10, 191-14:20:15 to Jul 11, 192-07:19:15z), for 2.4 hours later in the week for IMPACT on day 196 (Jul 15, 196-12:36:12z/14:59:32z) and again for 2.2 hours later in the week for IMPACT on day 197 (Jul 16, 197-09:48:31z/11:59:31z). The buffers were finally emptied using a 70 meter pass on Saturday, Jul 16. See DR# C108122 for more information. * On day 194 (Jul 13), the 14th HGA Calibration was successfully executed on Ahead at 1500z, and on Behind at 1600z. The data from both calibrations looked good. * On day 195 (Jul 14), the 39rd momentum dump on Ahead was successfully executed at 1500Z, which imparted a delta V of 0.0879 m/sec. * On day 193 (Jul 12), during the DSS 14 support for Behind, turbo decoder lock was lost briefly beginning at 1719z. This resulted in the loss of 14 frames of SECCHI SSR data. A DR has been requested. * On day 193 (Jul 12), the 33rd momentum dump on Behind was successfully executed at 1930Z, which imparted a delta V of 0.071 m/sec. * On day 194 (Jul 13), the BEHIND S/C switched to routinely using the 160 kbps downlink rate for 34 meter antenna tracks and 480 kbps for 70 meter antenna tracks. * The average daily SSR playback volume was 3.8 gigabits for Ahead, and 6.1 gigabits for Behind. * PLASTIC is now using their new software for the lower telemetry rate on both spacecraft. Week 29 (Jul 18-24) * A test was conducted yesterday (Jul 19) using Behind with the ESA New Norcia station in western Australia. The test was conducted at the normal mode of 160 kbps, with Turbo 1/6 encoding. A previous test at 360 kbps with Turbo 1/4 encoding proved to be too weak. However, this test went well, and was consistent with a concurrent Canberra track. * The test of the 135 degree roll to observe comet Elenin from Behind is scheduled for Friday, July 22 between 12-14 UT. The MOC would like feedback from SECCHI within a week of the test. The rolls to observe the comet will take place between Aug 1-12. SECCHI asked for the start and stop times of the dwell period. The dwell time starts 17 minutes into the procedure (i.e. at 12:17 UT), and lasts for one hour and 20 minutes. * Ahead has 480 kbps passes on Monday, Jul 18, Tuesday, Jul 19, Wednesday, Jul 20, and Thursday, Jul 21, all using station 14. There are 8 passes during the week, and overall coverage is nominal. * Behind has 480 kbps passes on Thursday, Jul 21, Friday, Jul 22, and Saturday, Jul 23, all using station 63. There are 13 passes during the week, and overall coverage is nominal. Week 30 (Jul 25-31) * The 18th SECCHI stepped calibration roll on Ahead is scheduled for Tuesday, day 207 (Jul 26), starting at 7:15 UT. This is the midpoint roll, and lasts about 3 hours. System momentum is expected to be about 7 N-m-s. * The SECCHI stepped calibration roll on Behind has been moved ahead a week, because of the comet Elenin observations, and is also scheduled for Jul 26, starting at 9:00 UT. This is also the midpoint roll. System momentum is expected to be about 4 N-m-s. * There have been several changes to the DSN schedule for Ahead during the week, due to support needed for another mission. Two 34 meter stations on Jul 31 were swapped for a 70 meter support. Ahead has 480 kbps passes on Monday, Jul 25 (D63), Tuesday, Jul 26 (D63), Wednesday, Jul 27 (D63), and Sunday, Jul 31 (D14). There are 12 passes during the week, and overall coverage is 1.5 hours above nominal. * Behind has 480 kbps passes on Friday, Jul 29, using stations 14 and 43. There are 14 passes during the week, and overall coverage is 6.5 hours above nominal. Week 31 (Aug 1-7) * The launch window for JUNO opens at 15:26 on Aug 5. This is the first of several upcoming launches that will impact the STEREO schedule. If JUNO doesn't launch the first day, the Ahead pass on Saturday, Aug 6, may be reduced by 50 minutes. * The 135 degree rolls on Behind to observe comet Elenin will start on Aug 1. The rolls will be between 8-10 UT each day, except for Aug 5 and Aug 12, when the rolls will be between 10-12 UT. * Ahead has 480 kbps passes on Monday, Aug 1 (D14), Tuesday, Aug 2 (D14), Wednesday, Aug 3 (D63), and Thursday, Aug 4 (D43). There are 9 passes during the week, and overall coverage is nominal. * Behind has 480 kbps passes on Thursday, Aug 4 (D14), and Friday, Aug 5 (D43). There are 13 passes during the week, and overall coverage is nominal. Week 32 (Aug 8-14) * The 135 degree rolls on Behind to observe comet Elenin will continue through Aug 12. The rolls will be between 8-10 UT each, except for Aug 12, when the roll will be between 10-12 UT. * Ahead has 480 kbps passes on Friday, Aug 12 (D14), Saturday, Aug 13 (D63), and Sunday, Aug 14 (D14). There are 10 passes during the week, and overall coverage is nominal. * Behind has 480 kbps passes on Tuesday, Aug 9 (D14 and D63), and Thursday, Aug 11 (D63). There are 14 passes during the week, and overall coverage is nominal. Week 33 (Aug 15-21) * The MOC network will be refreshed between 15-23 UT on Monday, Aug 15. This will be between passes, and will not affect operations. * The external network switch at APL will be upgraded on Wednesday, Aug 17, at 03:35 UT. This will also be between tracks. * Ahead has 480 kbps passes on Monday, Aug 15 (D63), Tuesday, Aug 16 (D14), Wednesday, Aug 17 (D14), Thursday, Aug 18 (D14), and Friday, Aug 19 (D14). There are 8 passes during the week, and overall coverage is nominal. * Behind has 480 kbps passes on Tuesday, Aug 16, twice on Friday, Aug 19, and Sunday, Aug 21, all using station 14. There are 15 passes during the week, and overall coverage is 8.1 hours above nominal. Week 34 (Aug 22-28) * The 40th momentum dump on Ahead is scheduled for Wednesday, Aug 24, starting at 15:00 UT. * The 35th momentum dump on Behind is also scheduled for Wednesday, Aug 24, starting at 18:00 UT. * Ahead has 480 kbps passes on Monday, Aug 22 (D63), Wednesday, Aug 24 (D14), Friday, Aug 26 (D63), Saturday, Aug 27 (D14), and Sunday, Aug 28 (D14). There are 11 passes during the week, and overall coverage is nominal. * Behind has a 480 kbps pass on Monday, Aug 22 using station 43. There are 14 passes during the week, and overall coverage is 5.6 hours above nominal. Week 35 (Aug 29-Sep 4) * Ahead has 480 kbps passes on Monday, Aug 29 (D63), Tuesday, Aug 30 (D14), Wednesday, Aug 31 (D63), Thursday, Sep 1 (D14), Friday, Sep 2 (D14), and Sunday, Sep 4 (D14). There are 11 passes during the week, and overall coverage is nominal. * Behind has 480 kbps passes on Monday, Aug 29 (D43), Wednesday, Aug 31 (D14), and Thursday, Sep 1 (D63). There are 13 passes during the week, and overall coverage is 1.3 hours above nominal. Week 36 (Sep 5-11) * Monday, Sep 5 is Labor Day. APL will be closed for the holiday. * Thursday, Sep 8 is the opening of the launch window for the GRAIL mission. This is a very intense mission, lasting just 9 months, and will require a lot of track time. This will affect the DSN scheduling for STEREO. The project is looking into getting support from ESA stations to cover the shortfall. * Ahead has 480 kbps passes on Tuesday, Sep 6 (D14), Thursday, Sep 8 (D43), and Friday, Sep 9 (D63 and D14). There are 11 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) * There is only 6 hours of coverage on Friday, Sep 16. The in situ instruments should probably be okay, but SECCHI should reduce their schedule. The following pass on Saturday is a 70 meter station. * There is a gap of 19 days in coverage from southern hemisphere stations for the Ahead spacecraft starting in week 37. This will affect the accuracy of the ephemeris calculations. Use of the ESA New Norcia station would mitigate this problem. * Ahead has 480 kbps passes on Monday, Sep 12 (D14), Tuesday, Sep 13 (D63), Wednesday, Sep 14 (D14), Thursday, Sep 15 (D63), and Saturday, Sep 17 (D63). There are 10 passes during the week, and overall coverage is below nominal, particularly for Friday. Similar situations are expected for the next several weeks. * 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), Saturday, Sep 17 (D14), and Sunday, Sep 18 (D63). There are 10 passes during the week, and overall coverage is nominal. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 29: M Jul 18 (199) Ahead: 480 kbps downlink on station 14 Behind: Test 06:25-06:50 with ESA New Norcia station T Jul 19 (200) Ahead: 480 kbps downlink on station 14 W Jul 20 (201) Ahead: 480 kbps downlink on station 14 T Jul 21 (202) Ahead: 480 kbps downlink on station 14 Behind: 480 kbps downlink on station 63 F Jul 22 (203) Behind: 480 kbps downlink on station 63 Behind: Test of 135 degree roll for comet Elenin, 12-14 UT S Jul 23 (204) Behind: 480 kbps downlink on station 63 S Jul 24 (205) ------------------------------------------------------------------------------- Scheduled activities for Week 30: M Jul 25 (206) Ahead: 480 kbps downlink on station 63 T Jul 26 (207) Ahead: SECCHI stepped calibration roll, 7:15 UT Behind: SECCHI stepped calibration roll, 9:00 UT Ahead: 480 kbps downlink on station 63 W Jul 27 (208) Ahead: 480 kbps downlink on station 63 T Jul 28 (209) F Jul 29 (210) Behind: 480 kbps downlink on stations 14 and 43 S Jul 30 (211) S Jul 31 (212) Ahead: 480 kbps downlink on station 14 ------------------------------------------------------------------------------- Scheduled activities for Week 31: M Aug 01 (213) Behind: 135 degree roll to observe comet Elenin, 8-10 UT Ahead: 480 kbps downlink on station 14 T Aug 02 (214) Behind: 135 degree roll to observe comet Elenin, 8-10 UT Ahead: 480 kbps downlink on station 14 W Aug 03 (215) Behind: 135 degree roll to observe comet Elenin, 8-10 UT Ahead: 480 kbps downlink on station 63 T Aug 04 (216) Behind: 135 degree roll to observe comet Elenin, 8-10 UT Ahead: 480 kbps downlink on station 43 Behind: 480 kbps downlink on station 14 F Aug 05 (217) Behind: 135 degree roll to observe comet Elenin, 10-12 UT Behind: 480 kbps downlink on station 43 S Aug 06 (218) Behind: 135 degree roll to observe comet Elenin, 8-10 UT S Aug 07 (219) Behind: 135 degree roll to observe comet Elenin, 8-10 UT Notes * Aug 1-12 Behind: Spacecraft rolls to observe comet Elenin ------------------------------------------------------------------------------- Scheduled activities for Week 32: M Aug 08 (220) Behind: 135 degree roll to observe comet Elenin, 8-10 UT T Aug 09 (221) Behind: 135 degree roll to observe comet Elenin, 8-10 UT Behind: 480 kbps downlink on stations 14 and 63 W Aug 10 (222) Behind: 135 degree roll to observe comet Elenin, 8-10 UT T Aug 11 (223) Behind: 135 degree roll to observe comet Elenin, 8-10 UT Behind: 480 kbps downlink on station 63 F Aug 12 (224) Behind: 135 degree roll to observe comet Elenin, 10-12 UT Ahead: 480 kbps downlink on station 14 S Aug 13 (225) Ahead: 480 kbps downlink on station 63 S Aug 14 (226) Ahead: 480 kbps downlink on station 14 Notes * Aug 1-12 Behind: Spacecraft rolls to observe comet Elenin ------------------------------------------------------------------------------- Scheduled activities for Week 33: M Aug 15 (227) Ahead: 480 kbps downlink on station 63 T Aug 16 (228) Ahead: 480 kbps downlink on station 14 Behind: 480 kbps downlink on station 14 W Aug 17 (229) Ahead: 480 kbps downlink on station 14 T Aug 18 (230) Ahead: 480 kbps downlink on station 14 F Aug 19 (231) Ahead: 480 kbps downlink on station 14 Behind: 480 kbps downlink on station 14 (twice) S Aug 20 (232) S Aug 21 (233) Behind: 480 kbps downlink on station 14 ------------------------------------------------------------------------------- Scheduled activities for Week 34: M Aug 22 (234) Ahead: 480 kbps downlink on station 63 Behind: 480 kbps downlink on station 43 T Aug 23 (235) W Aug 24 (236) Momentum dumps, Ahead: 15:00 UT, Behind: 18:00 UT Ahead: 480 kbps downlink on station 14 T Aug 25 (237) F Aug 26 (238) Ahead: 480 kbps downlink on station 63 S Aug 27 (239) Ahead: 480 kbps downlink on station 14 S Aug 28 (240) Ahead: 480 kbps downlink on station 14 ------------------------------------------------------------------------------- Scheduled activities for Week 35: M Aug 29 (241) Ahead: 480 kbps downlink on station 63 Behind: 480 kbps downlink on station 43 T Aug 30 (242) Ahead: 480 kbps downlink on station 14 W Aug 31 (243) Ahead: 480 kbps downlink on station 63 Behind: 480 kbps downlink on station 14 T Sep 01 (244) Ahead: 480 kbps downlink on station 14 Behind: 480 kbps downlink on station 63 F Sep 02 (245) Ahead: 480 kbps downlink on station 14 S Sep 03 (246) S Sep 04 (247) Ahead: 480 kbps downlink on station 14 ------------------------------------------------------------------------------- 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 F Sep 09 (252) Ahead: 480 kbps downlink on stations 63 and 14 S Sep 10 (253) 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 station 43 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 ------------------------------------------------------------------------------- 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