STEREO Weekly Meeting Minutes for 2012-05-15 (Week 20) ANNOUNCEMENTS ------------- * The will be a commercial power outage at APL on Saturday and Sunday, May 26-27. The MOC will stay up on generator power, and connectivity with the instrument teams should not be interrupted. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 19 (May 7-13) * On day 131 (May 10), for the DSS-25 support for Ahead, initial acquisition of signal was delayed 46 minutes as the antenna brakes could not be released. The antenna drive motors were reset and telemetry lock was re-established at 1531z. SSR pointers were repositioned and all SSR data were recovered. This anomaly resulted in the loss of 46 minutes of commanding, real-time telemetry and tracking data. See DR# G112698 for more information. * On day 128 (May 7), during the DSS-63 support for Behind, turbo decoder lock was lost briefly beginning at 1134z and again at 1409z. This anomaly resulted in the loss of 158 frames of SSR data. See DR# N108080 for more information. * On day 129 (May 8), during the DSS-63 support for Behind, turbo decoder lock was lost briefly at 1250z. This anomaly resulted in the loss of one frame of SSR data. See DR# N108084 for more information. * On day 130 (May 9), during the DSS-55 support for Behind, turbo decoder lock was lost briefly beginning at 1348z. This anomaly resulted in the loss of four frames of SSR data. See DR# N108088 for more information. * On day 132 (May 11), during the DSS-63 support for Behind, turbo decoder lock was lost briefly at 0914z. This anomaly resulted in the loss of one frame of SSR data. See DR# N108097 for more information. * On day 133 (May 12), during the DSS-55 support for Behind, turbo decoder lock was lost briefly beginning at 1345z. This anomaly resulted in the loss of five frames of SSR data. See DR# N108099 for more information. * On day 133 (May 12), for the DSS-15 support for Behind, the transmitter was declared red at BOT at 2020z. The support remained downlink only for its entirety. This anomaly resulted in the loss of 231 minutes of commanding and two-way tracking data. All SSR data were recovered. See DR# G112712 for more information. * The average daily SSR playback volume during the week was 5.2 gigabits for Ahead, and 5.4 gigabits for Behind. Week 20 (May 14-20) * The 41st momentum dump on Behind is scheduled for Tuesday, May 15, with ignition at 17:00 UT. * Turbo decoder lock was lost briefly at 04:06 yesterday (May 14) during the station 43 pass for Behind. This resulted in the loss of about 400 frames of data. * Ahead has 70 meter passes on Wednesday, May 16 (D14 at 720 kbps), Thursday, May 17 (D14 at 720 kbps), Friday, May 18 (D63), Saturday, May 19 (D14, D43), and Sunday, May 20 (D63). There are 11 passes during the week, and overall coverage is nominal. The station 15 pass on Monday, May 14, the station 25 pass on Tuesday, May 15, the station 55 pass on Saturday, May 19, and the station 25 pass on Sunday, May 20, will all be carried out at 240 kbps. * Behind has 70 meter passes on Monday, May 14 (D43), Wednesday, May 16 (D63), Thursday, May 17 (D63), Friday, May 18 (D14 at 720 kbps), Saturday, May 19 (D14 at 720 kbps), and Sunday, May 20 (D63 at 720 kbsp). There are 8 passes during the week, and overall coverage is nominal. The station 54 pass on Monday, May 14 will be carried out at 240 kbps. Week 21 (May 21-27) * There is a 3 hour return-to-service track for station 65 with Behind on Friday, May 25, starting at 17:00 UT. There will be no SSR playback nor instrument commanding during this track. * Perihelion for Behind will occur on May 22. However, system momentum will be high, and the calibration roll is scheduled for the following week. * Ahead has 70 meter passes on Monday, May 21 (D14), Tuesday, May 22 (D14 at 720 kbps), Wednesday, May 23 (D14, D43), Thursday, May 24 (D63), Friday, May 25 (D63, D14 at 720 kbps), and Saturday, May 26 (D63, D43 at 720 kbps). There are 12 passes during the week, and overage coverage is nominal. * Behind has 70 meter passes on Monday, May 21 (D63 at 720 kbps), Tuesday, May 22 (D63 at 720 kbps), Wednesday, May 23 (D14 at 720 kbps), Thursday, May 24 (D63), Friday, May 25 (D63), and Saturday, May 26 (D63 at 720 kbps). There are 11 passes during the week, and overall coverage is nominal. The station 55 pass on Sunday, May 27 will be carried out at 240 kbps. Week 22 (May 28-Jun 03) * May 28 is Memorial Day, which is a holiday at APL. * The 47th momentum dump on Ahead is scheduled for Thursday, May 31, with ignition at 16:00 UT. * The 21st SECCHI stepped calibration roll on Behind is scheduled for May 29, starting at 06:05 UT. System momentum is expected to be 3 N-m-s. * Ahead has 70 meter tracks on Monday, May 28, and Tuesday, May 29, both using station 63. There are 13 tracks during the week, and overall coverage is nominal. The following tracks will be carried out at 240 kbps: Monday, May 28 (D25), Tuesday, May 29 (D15), Wednesday, May 30 (D54), Thursday, May 31 (D25), Friday, Jun 1 (D65), and Saturday, Jun 2 (D25). * Behind has 70 meter tracks on Monday, May 28 (D63), Tuesday, May 29 (D63 at 720 kbps), Thursday, May 31 (D14), Friday, Jun 1 (D63), Saturday, Jun 2 (D63), and Sunday, Jun 3 (D63). There are 9 passes during the week, and the overall coverage is nominal. The station 54 pass on Wednesday, May 30 will be carried out at 240 kbps. Week 23 (Jun 4-10) * Ahead has 70 meter passes on Tuesday, Jun 5 (D14), Thursday, Jun 7 (D63), and Friday, Jun 8 (D63, D14 at 720 kbps). There are 12 passes during the week, and the overall coverage is nominal. The following passes will be carried out at 240 kbps: Monday, Jun 4 (D55, D25), Tuesday, Jun 5 (D25), Wednesday, Jun 6 (D34), Saturday, Jun 9 (D26), and Sunday, Jun 10 (D54). * Behind has 70 meter passes on Monday, Jun 4 (D63 at 720 kbps), Tuesday, Jun 5 (D63 at 720 kbps), Friday, Jun 8 (D43, D14 at 720 kbps), Saturday, Jun 9 (D63), and Sunday, Jun 10 (D63 at 720 kbps). There are 9 passes during the week, and the overall coverage is nominal. The station 25 passes on Wednesday, Jun 6 and Sunday, Jun 10 will be carried out at 240 kbps. Week 24 (Jun 11-17) * Ahead has 70 meter passes on Monday, Jun 11 (D63), Tuesday, Jun 12 (D14 at 720 kbps), Wednesday, Jun 13 (D14), Friday, Jun 15 (D63 at 720 kbps), Saturday, Jun 16 (D63 at 720 kbps), and Sunday, Jun 17 (D63). There are 11 passes during the week, and the overall coverage is nominal. The station 54 pass on Thursday, Jun 14 will be carried out at 240 kbps. Passes with ESA's New Norcia station are scheduled for Wednesday, Jun 13, and Thursday, Jun 14. * Behind has 70 meter passes on Monday, Jun 11 (D63), Wednesday, Jun 13 (D14), Thursday, Jun 14 (D63), and Sunday, Jun 17 (D63), all at 720 kbps. There are 9 passes during the week, and overall coverage is nominal. The station 54 pass on Tuesday, Jun 12, and the station 26 pass on Saturday, Jun 16 will both be carried out at 240 kbps. Other * A question was raised about the usefulness of performing post-pass calibration for ranging on the DSN stations. FDF responded that this should be okay so long as the bias is known and the same throughout the pass, so that it can be corrected for. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 20: M May 14 (135) T May 15 (136) Behind: Momentum dump, 17:00 UT W May 16 (137) T May 17 (138) F May 18 (139) S May 19 (140) S May 20 (141) ------------------------------------------------------------------------------- Scheduled activities for Week 21: M May 21 (142) T May 22 (143) Behind: Perihelion W May 23 (144) T May 24 (145) F May 25 (146) Behind: Return-to-service track with station 65 S May 26 (147) S May 27 (148) ------------------------------------------------------------------------------- Scheduled activities for Week 22: M May 28 (149) Memorial Day T May 29 (150) Behind: SECCHI stepped calibration roll, 6:05 UT W May 30 (151) T May 31 (152) Ahead: Momentum dump, 16:00 UT F Jun 01 (153) S Jun 02 (154) S Jun 03 (155) ------------------------------------------------------------------------------- Scheduled activities for Week 23: M Jun 04 (156) T Jun 05 (157) W Jun 06 (158) T Jun 07 (159) F Jun 08 (160) S Jun 09 (161) S Jun 10 (162) ------------------------------------------------------------------------------- Scheduled activities for Week 24: M Jun 11 (163) T Jun 12 (164) W Jun 13 (165) T Jun 14 (166) F Jun 15 (167) S Jun 16 (168) S Jun 17 (169) ------------------------------------------------------------------------------- Upcoming events: 2012: * 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