STEREO Weekly Meeting Minutes for 2014-03-18 (Week 12) ANNOUNCEMENTS ------------- * None. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 11 (Mar 10-16) * On day 070 (Mar 11), the SSR science partitions on Ahead filled as follows: SWAVES (Part 13) remained 100% full at 0809z for 2.6 hours. SWAVES (Part 13) remained 100% full at 1444z for 5.4 hours. * On day 070 (Mar 11), MOps permanent macro release 1.1.18 was copied from C&DH RAM to EEPROM on Ahead. This release modified MOps macros to suppress invalid telemetry indications when the IMU is not powered. In addition, the IMU power on/off macros were copied from C&DH RAM to EEPROM. The entire set of MOps Reduced Gyro Operations macros now reside in EEPROM. * On day 071 (Mar 12), fault protection release 2.3.12 was loaded to C&DH EEPROM on Ahead. This release contains autonomy rules and associated macros used to support Reduced Gyro Operations. * On day 073 (Mar 14), at G&C's request, MOps increased the period between low wheel speed checks from one hour to three hours on Ahead. This will reduce the frequency of drops in fine-pointing should the reaction wheels be operating at low speeds for extended periods of time. There have not been any recent drops in fine-pointing on Ahead similar to the recent ones on Behind (see below), but there were some momentarily glitches in the Ahead roll on Mar 9 and 11 due to wheel speed crossings. * On day 069 (Mar 10), during the DSS-26 support for Behind, no commanding or ranging was conducted due to a transmitter problem. See DR #G114790 more information. * On day 075 (Mar 16), during the DSS-26 support for Behind, the downlink was dropped between 2110z and 2126z due to a software issue at the station. This anomaly resulted in the loss of 0.3 hours of SSR data. See DR #G114831 more information. * The Behind spacecraft continued to drop fine-pointing intermittently throughout the week as a result of G&C software reacting to low reaction wheel speeds. On day 073, at G&C's request, MOps increased the period between low wheel speed checks from one hour to three hours. This will reduce the frequency of drops in fine-pointing should the reaction wheels be operating at low speeds for extended periods of time. * The average daily SSR playback volume during the week was 3.1 gigabits for Ahead, and 3.3 gigabits for Behind. Week 12 (Mar 17-23) * Software updates were loaded to RAM to increase the timeout parameter for computing quaternions if the star tracker drops out. This is another change related to reduced gyro operations. * Ahead has 8 passes during the week, and overall coverage is nominal. A 70 meter pass is scheduled for Tuesday, Mar 18 (D14). * Behind has 11 passes during the week, and overall coverage is nominal. There is a 70 meter pass scheduled on Saturday, Mar 22 (D14 at 720 kbps). The following passes will be carried out at 160 kbps: Thursday, Mar 20 (D26), and Sunday, Mar 23 (D26). Week 13 (Mar 24-30) * The 66th momentum dump on Ahead is scheduled for Wednesday, Mar 26, with ignition at 21:30 UT. * The 28th SECCHI stepped calibration roll on Behind is scheduled for Tuesday, Mar 25, starting at 16:40 UT. This is the midpoint roll. The system momentum will be about 5 N-m-s. * The final MOps permanent macro release 1.1.19 and fault protection release 2.3.13 will be written to EEPROM on Behind on Thursday, Mar 27. * Ahead has 10 passes during the week, and overall coverage is nominal. A 70 meter pass is scheduled for Wednesday, Mar 26 (D14 at 720 kbps). The following passes will be carried out at 160 kbps: Monday, Mar 24 (D26), Tuesday, Mar 25 (D24), and Thursday, Mar 27 (D25). * Behind has 10 passes during the week, and overall coverage in nominal. There are three 70 meter passes scheduled: Monday, Mar 24 (D43, D14 at 720 kbps), and Tuesday, Mar 25 (D14). The following passes will be carried out at 160 kbps: Thursday, Mar 27 (D55), Friday, Mar 28 (D26), and Sunday, Mar 30 (D26). The station 26 pass on Saturday, Mar 29 will be carried out at 240 kbps. Week 14 (Mar 31-Apr 6) * The 61st momentum dump on Behind is scheduled for Wednesday, Apr 2, starting at 15:30 UT. * A Project Interface Test (PIT) with station 25 is scheduled for Behind on Thursday, Apr 3. There will be no instrument commanding or SSR playback during this test. * A Return-To-Service test with Behind with station 63 is scheduled for Saturday, Apr 5. There will be no instrument commanding or SSR playback during this test. * Ahead has 11 passes during the week, and overall coverage is short 13.3 hours, mainly between Monday-Thursday, Mar 31-Apr 3. 70 meter passes are scheduled for Friday, Apr 4 (D14 at 720 kbps), and Sunday, Apr 6 (D43). The following passes will be carried out at 160 kbps, all using station 26: Monday, Mar 31, Wednesday, Apr 2, and Saturday, Apr 5. The station 26 pass on Sunday, Apr 6, will be carried out at 240 kbps. * Behind has 8 passes during the week, and overall coverage is short 6.4 hours, mainly between Thursday-Friday, Apr 3-4. 70 meter passes are scheduled for Monday, Mar 31 (D14 at 720 kbps), and Sunday, Apr 6 (D43). The following passes will be carried out at 160 kbps: Tuesday, Apr 1 (D26), and Wednesday, Apr 2 (D55). Week 15 (Apr 7-13) * A Return-To-Service test with Ahead with station 63 is scheduled for Monday, Apr 7. There will be no instrument commanding or SSR playback during this test. * Ahead has 13 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Apr 7, and Thursday, Apr 10, both using station 14 at 720 kbps. The following passes will be carried out at 160 kbps: Thursday, Apr 10 (D26), Saturday, Apr 12 (D55), and Sunday, Apr 13 (D65, D25). * Behind has 11 passes during the week, and overall coverage is nominal. A 70 meter pass is scheduled for Tuesday, Apr 8 (D14 at 720 kbps). The following passes will be carried out at 160 kbps: Tuesday, Apr 8 (D26), Thursday, Apr 10 (D55, D25), Saturday, Apr 12 (D15), and Sunday, Apr 13 (D55, D26). The station 26 pass on Friday, Apr 11, will be carried out at 240 kbps. Week 16 (Apr 14-20) * Ahead has 13 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Apr 14 (D63 at 720 kbps), Tuesday, Apr 15 (D63, D14 at 720 kbps), Wednesday, Apr 16 (D63), and Friday, Apr 18 (D43). The following passes will be carried out at 160 kbps: Thursday, Apr 17 (D55, D24), Friday, Apr 18 (D24), Saturday, Apr 19 (D15), and Sunday, Apr 20 (D55). * Behind has 10 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for every day of the week except Friday, and all of the passes are carried out at 720 kbps except Sunday. The following passes will be carried out at 160 kbps: Thursday, Apr 17 (D25), Friday, Apr 18 (D55), Saturday, Apr 19 (D24), and Sunday, Apr 20 (D25). Week 17 (Apr 21-27) * Ahead has 11 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Apr 21 (D63 at 720 kbps), Tuesday, Apr 22 (D63), Wednesday, Apr 23 (D14 at 720 kbps), Thursday, Apr 24 (D43), and Friday, Apr 25 (D43 at 720 kbps). The following passes will be carried out at 160 kbps: Thursday, Apr 24 (D55), Friday, Apr 25 (D55), Saturday, Apr 26 (D54, D25), and Sunday, Apr 27 (D54, D25). * Behind has 11 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Apr 21 (D63 at 720 kbps), Wednesday, Apr 23 (D43), and Sunday, Apr 27 (D43 at 720 kbps). The following passes will be carried out at 160 kbps: Wednesday, Apr 23 (D54), Thursday, Apr 24 (D54), Friday, Apr 25 (D55), Saturday, Apr 26 (D55, D15), and Sunday, Apr 27. The station 26 pass on Friday, Apr 25, will be carried out at 240 kbps. Other * It was remarked that data coverage appears to improve significantly with the return of station 63. * Discussions of possible ESA support are still ongoing. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 12: M Mar 17 (076) T Mar 18 (077) W Mar 19 (078) T Mar 20 (079) F Mar 21 (080) S Mar 22 (081) S Mar 23 (082) ------------------------------------------------------------------------------- Scheduled activities for Week 13: M Mar 24 (083) T Mar 25 (084) Behind: SECCHI stepped calibration roll, 16:40 UT W Mar 26 (085) Ahead: Momentum dump, 21:30 UT T Mar 27 (086) F Mar 28 (087) S Mar 29 (088) S Mar 30 (089) ------------------------------------------------------------------------------- Scheduled activities for Week 14: M Mar 31 (090) T Apr 01 (091) W Apr 02 (092) Behind: Momentum dump, 15:30 UT T Apr 03 (093) Behind: PIT test with station 25 F Apr 04 (094) S Apr 05 (095) Behind: Return-to-service test with station 63 S Apr 06 (096) Notes: * Significant telemetry shortages are expected for both spacecraft during the week. ------------------------------------------------------------------------------- Scheduled activities for Week 15: M Apr 07 (097) Ahead: Return-to-service test with station 63 T Apr 08 (098) W Apr 09 (099) T Apr 10 (100) F Apr 11 (101) S Apr 12 (102) S Apr 13 (103) ------------------------------------------------------------------------------- Scheduled activities for Week 16: M Apr 14 (104) T Apr 15 (105) W Apr 16 (106) T Apr 17 (107) F Apr 18 (108) S Apr 19 (109) S Apr 20 (110) ------------------------------------------------------------------------------- Scheduled activities for Week 17: M Apr 21 (111) T Apr 22 (112) W Apr 23 (113) T Apr 24 (114) F Apr 25 (115) S Apr 26 (116) S Apr 27 (117) ------------------------------------------------------------------------------- Upcoming events: 2014: * Apr 29 Behind: Mercury transit * Sep 07-Nov 15 Behind: Passage of Comet Siding Spring through HI2-B * Sep 21 MAVEN arrival at Mars * Oct 17 Behind: Comet Siding Spring encounter with Mars 2015: * Jan 14 - Mar 19 (TBC) Behind: Spacecraft behind Sun * Mar DAWN - Ceres arrival * Feb 11 - Jul 08 (TBC) Ahead: Spacecraft behind Sun * Aug 25 - Oct 19 (TBC) Behind: Possible interference from Sun * Jul DAWN - End of nominal mission 2016: * Jul 5 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