STEREO Weekly Meeting Minutes for 2013-06-04 (Week 23) ANNOUNCEMENTS ------------- * None INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. See discussion below about recent anomaly for Ahead IMU-2 Z-axis gyro laser. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 22 (May 27-Jun 2) * On day 147 (May 27), during the DSS-14 support for Ahead, turbo decoder lock was lost intermittently beginning at 1617z through 1619z due to antenna encoder glitches. This anomaly resulted in the loss of 4877 frames of SSR data. See DR #G113968 for more information. * On day 149 (May 29), during the DSS-63 support for Ahead, turbo decoder lock was lost intermittently beginning at 0557z through 0630z. This anomaly resulted in the loss of ten frames of SSR data. See DR #N108892 for more information. * On day 151 (May 31), during the DSS-63 support for Ahead, turbo decoder lock was lost intermittently beginning at 0526z through 0717z. This anomaly resulted in the loss of 43 frames of SSR data. See DR #N108896 for more information. * On day 147 (May 27), Ahead IMU-2 Z-axis gyro laser intensity monitor (LIM) began decreasing in intensity more rapidly and the cause is currently unknown. The engineer team is actively investigating the anomaly (AR ST-A-2175). Also, a concept of operations for limited gyro use is being developed to preserve gyro lifetime. * On day 150 (May 30), the 57th momentum dump was executed successfully on Ahead at 1630Z, which imparted a delta V of 0.088 m/sec. * On day 153 (Jun 2), the SSR science partitions on Ahead filled as follows: SECCHI (Part 19) reached 100% full at 1825z for 0.9 hours. The cause was due to the SSR science partitions emptying near end of track and the relative SSR read/write pointer position prevented the autonomous pointer moves that free SSR space. * On day 148 (May 28), during the DSS-63 support for Behind, the receiver and ranging processor unexpectedly went out of lock beginning at 1639z through 1642z. Also during this track, turbo decoder lock was lost intermittently between 1420z-1612z and 1654z-1727z. These anomalies resulted in the loss of 3613 frames of SSR data. See DRs #M107326 and #N108893 respectively for more information. * On day 150 (May 30), during the DSS-15 support for Behind, turbo decoder lock was lost briefly at 151-0119z. This anomaly resulted in the loss of one frame of SSR data. See DR #N108897 for more information. * On day 151 (May 31), during the DSS-63 support for Behind, turbo decoder lock was lost intermittently beginning at 1102z through 1401z. This anomaly resulted in the loss of 31 frames of SSR data. See DR #N108898 for more information. * On day 147 (May 27), the SSR science partitions on Behind filled as follows: SECCHI (Part 19) reached 100% full at 0141z for 0.1 hours. The cause was due to the SSR science partitions emptying near end of track and the relative SSR read/write pointer position prevented the autonomous pointer moves that free SSR space. * On day 151 (May 31), the SSR science partitions on Behind filled as follows: SECCHI (Part 19) reached 100% full at 1519z for 0.3 hours. The cause was due to the SSR science partitions emptying near end of track and the relative SSR read/write pointer position prevented the autonomous pointer moves that free SSR space. * There was some discussion of the problems with the SECCHI partitions filling up. This problem has been showing up on lengthy 720 kbps tracks, and only when the other science partitions except SECCHI are empty. One possible solution is for the MOC to manually reposition the pointers in such tracks. These manual repositions would show up in the weekly schedule. Alternatively, the SECCHI team could modify their calculation to determine how much data can be taken based on the DSN schedule. * The average daily SSR playback volume during the week was 4.6 gigabits for Ahead, and 4.8 gigabits for Behind. Week 23 (Jun 3-9) * An engineering demo using station 26 with the STEREO Behind spacecraft will take place on Tuesday, Jun 4. No SSR playback or commanding will be available during this test. The test will use the new X-band and K-band attenuators to look at the strong spaceweather beacon signal. * Wednesday, Jun 5, is the 52nd Behind momentum dump at 18:30 UT. * An additional return-to-service test for station 43 is scheduled for the Ahead spacecraft on Thursday, Jun 6. This test is to confirm the fix for the spacecraft ranging problem. There will be no SSR downlink or instrument commanding during this pass. * Ahead has 12 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Jun 3 (D63), Tuesday, Jun 4 (D14), Friday, Jun 7 (D63), and Saturday, Jun 8 (D14 at 720 kbps). The following passes will be carried out at 160 kbps: Wednesday, Jun 5 (D25) and Sunday, Jun 9 (D15). An ESA New Norcia pass is scheduled for Wednesday, Jun 5. * Behind has 11 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, May 27 (D14 at 720 kbps) and Friday, Jun 7 (D63 at 720 kbps). The following passes will be carried out at 160 kbps: Saturday, Jun 8 (D54), and Sunday, Jun 9 (D54). An ESA Malargue pass is scheduled for Tuesday, Jun 4, and an ESA New Norcia pass is scheduled for Friday, Jun 7. Week 24 (Jun 10-16) * Tuesday, Jun 11, is the 26th Ahead SECCHI stepped calibration roll at 08:35 UT. This is the midpoint roll. * Behind will be at perihelion on Saturday, Jun 15. * Ahead has 13 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Tuesday, Jun 11 (D43), Thursday, Jun 13 (D43), Friday, Jun 14 (D63 at 720 kbps), and Saturday, Jun 15 (D14 at 720 kbps). The following passes will be carried out at 160 kbps: Monday, Jun 10 (D26, D15) and Tuesday, Jun 11 (D26). * Behind has 13 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Tuesday, Jun 11 (D63 at 720 kbps), Thursday, Jun 13 (D43), Friday, Jun 14, (D43, D63), and Saturday, Jun 15 (D14 at 720 kbps). The following passes will be carried out at 160 kbps: Monday, Jun 10 (D15), Thursday Jun 13 (D25), and Sunday, Jun 16 (D15). The following passes will be carried out at 240 kbps: Monday, Jun 10 (D26). * Station 43 is planned for both spacecraft during the week. There is currently a problem with the motor to retract a mirror which could cause problems at high elevations during heavy rain. It's not yet known when this problem will be fixed. Week 25 (Jun 17-23) * The 25th SECCHI stepped calibration roll on Behind will be carried out on Tuesday, Jun 18, starting at 17:00 UT. * Ahead has 10 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Jun 17 (D63), Thursday, Jun 20 (D14), and Saturday, Jun 22 (D63). The station 26 pass on Friday, Jun 21, will be carried out at 240 kbps. The following passes will be carried out at 160 kbps: Tuesday, Jun 18 (D26), Thursday, Jun 20 (D15), and Sunday, Jun 23 (D25). * Behind has 9 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Jun 17 (D14), Wednesday, Jun 19 (D63), Friday, Jun 21 (D63), and Saturday, Jun 22 (D63), all at 720 kbps. The station 54 pass on Sunday, Jun 23, will be carried out at 160 kbps. Week 26 (Jun 24-30) * On Wednesday, Jun 26, station 54 will be shadowing the Behind pass on station 55 to test a new antenna controller. * Ahead has 13 passes during the week, and overall coverage is short 5 hours, mainly on Wednesday, Jun 26. 70 meter passes are scheduled for Monday, Jun 24 (D14), Thursday, Jun 27 (D14, D43), Saturday, Jun 29 (D14 at 720 kbps), and Sunday, Jun 30 (D63 at 720 kbps, D43). The following passes will be carried out at 160 kbps: Tuesday, Jun 25 (D26), and Wednesday, Jun 26 (D65). An ESA New Norcia pass is scheduled for Tuesday, Jun 25. * Behind has 11 passes during the week, and overall coverage is short 9.4 hours, mainly on Wednesday and Thursday. 70 meter passes are scheduled for Tuesday, Jun 25 (D63 at 720 kbps), Friday, Jun 28 (D43, D63 at 720 kbps), Saturday, Jun 29 (D63 at 720 kbsp), and Sunday, Jun 30 (D63 at 720 kbps). The following passes will be carried out at 160 kbps: Wednesday, Jun 26 (D54), Thursday, Jun 27 (D26), and Saturday, Jun 29 (D26). Week 27 (Jul 1-7) * A return-to-service track for station 24 is scheduled with the Ahead spacecraft on Wednesday, Jul 3. There will be no SSR downlink or instrument commanding during this track. * Jul 4 is Independence Day, which is a holiday at APL. * Ahead has 9 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Friday, Jul 5, and Sunday, Jul 7, both using station 63 at 720 kbps. The following passes will be carried out at 160 kbps: Monday, Jul 1 (D26), and Thursday, Jul 4 (D15). * Behind has 10 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Jul 1 (D43), Wednesday, Jul 3 (D63 at 720 kbps), Friday, Jul 5 (D14 at 720 kbps), Saturday, Jul 6 (D63 at 720 kbps), and Sunday, Jul 7 (D63 at 720 kbps). Week 28 (Jul 8-14) * Additional engineering demos using attenuators with the STEREO beacon broadcast on Behind are scheduled for Monday, Jul 8 (D24), and Tuesday, Jul 9 (D55). * The 18th HGA calibrations are scheduled for the Ahead spacecraft on Tuesday, Jul 9, at 17:00 UT, and for the Behind spacecraft on Wednesday, Jul 10, at 16:00 UT. * A return-to-service track for station 55 with the Ahead spacecraft is scheduled for Wednesday, Jul 10. There will be no SSR downlink or instrument commanding during this track. * Ahead has 10 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Jul 8, Wednesday, Jul 10, Thursday, Jul 11, and Friday, Jul 12, all using station 14. The station 15 pass on Saturday, Jul 13, will be carried out at 160 kbps. * Behind has 8 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Jul 8, and Tuesday, Jul 9, both using station 63 at 720 kbps. The following passes will be carried out at 160 kbps: Saturday, Jul 13 (D65), and Sunday, Jul 14 (D24). Week 29 (Jul 15-21) * Ahead has 8 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Jul 15 (D14), Wednesday, Jul 17 (D14), Thursday, Jul 18 (D43, D14), Friday, Jul 19 (D43), Saturday, Jul 20 (D14), and Sunday, Jul 21 (D14). * Behind has 12 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Jul 15 (D43), and Wednesday, Jul 17 (D43, D14 at 720 kbps). The following passes will be carried out at 160 kbps: Saturday, Jul 20 (D54, D24). Other * A question was raised about the status of the plan for optimizing telemetry rates for the individual antennas. This plan has been on hold, but work is expected to resume soon. * Station 27 will be decommissioned at the end of the year. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 23: M Jun 03 (154) T Jun 04 (155) Behind: Engineering demo with station 26 W Jun 05 (156) Behind: Momentum dump, 18:30 UT T Jun 06 (157) Ahead: Return-to-service track for D43 F Jun 07 (158) S Jun 08 (159) S Jun 09 (160) ------------------------------------------------------------------------------- Scheduled activities for Week 24: M Jun 10 (161) T Jun 11 (162) Ahead: SECCHI stepped calibration roll, 08:35 UT W Jun 12 (163) T Jun 13 (164) F Jun 14 (165) S Jun 15 (166) Behind: Perihelion S Jun 16 (167) ------------------------------------------------------------------------------- Scheduled activities for Week 25: M Jun 17 (168) T Jun 18 (169) Behind: SECCHI stepped calibration roll, 17:00 UT W Jun 19 (170) T Jun 20 (171) F Jun 21 (172) S Jun 22 (173) S Jun 23 (174) ------------------------------------------------------------------------------- Scheduled activities for Week 26: M Jun 24 (175) T Jun 25 (176) W Jun 26 (177) Behind: D54 shadow track during D55 pass T Jun 27 (178) F Jun 28 (179) S Jun 29 (180) S Jun 30 (181) Notes: * Significant telemetry shortages are expected during the week for both spacecraft. ------------------------------------------------------------------------------- Scheduled activities for Week 27: M Jul 01 (182) T Jul 02 (183) W Jul 03 (184) Ahead: Return-to-service track for station 24 T Jul 04 (185) Independence Day F Jul 05 (186) S Jul 06 (187) S Jul 07 (188) ------------------------------------------------------------------------------- Scheduled activities for Week 28: M Jul 08 (189) Behind: Engineering demo with station 24 T Jul 09 (190) Ahead: HGA calibration, 17:00 Behind: Engineering demo with station 55 W Jul 10 (191) Ahead: Return-to-service track for station 55 Behind: HGA calibration, 16:00 T Jul 11 (192) F Jul 12 (193) S Jul 13 (194) S Jul 14 (195) ------------------------------------------------------------------------------- Scheduled activities for Week 29: M Jul 15 (196) T Jul 16 (197) W Jul 17 (198) T Jul 18 (199) F Jul 19 (200) S Jul 20 (201) S Jul 21 (202) ------------------------------------------------------------------------------- Upcoming events: 2013: * Nov 28 Both: Perihelion passage of Comet ISON http://stereo-ssc.nascom.nasa.gov/comet_ison/ * 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 * Sep 07-Nov 15 Behind: Passage of Comet Siding Spring through HI2-B * Oct 15 Behind: End use of 480 kbps on 70 m DSN subnet * Oct 17 Behind: Comet Siding Spring encounter with Mars 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 * Jul Juno arrival at Jupiter 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