STEREO Weekly Meeting Minutes for 2014-06-24 (Week 26) ANNOUNCEMENTS ------------- * See the discussion below about solar conjunction operation testing during week 28. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 25 (Jun 16-22) * On day 169 (Jun 18), during the DSS-55 support for Ahead, turbo decoder lock was lost at 0603z. This anomaly resulted in the loss of 852 frames of SSR data. See DR #N109618 for more information. * On day 171 (Jun 20), during the DSS-65 support for Ahead, telemetry lock was lost intermittently between 1038z through 1314z due to rain. This anomaly resulted in the loss of 3290 frames of SSR data. See DR #M108037 for more information. * On day 173 (Jun 22), for the DSS-14 support for Ahead, the transmitter was declared red prior to the start of the track at 1755z. This anomaly resulted in the loss of all commanding and two-way tracking data for the duration of the support. All SSR data were received. See DR# G115164 for more information. * On day 171 (Jun 20), G&C parameters version 1.3.1 and MOps macros 1.1.21 were loaded to EEPROM on Ahead in preparations for solar conjunction testing to commence on day 187. * On day 167 (Jun 16), during the DSS-63 support for Behind, turbo decoder lock was lost briefly at 0804z. This anomaly resulted in the loss of one frame of SSR data. * On day 170 (Jun 19), during the DSS-24 support for Behind, turbo decoder lock was lost intermittently between 171-0010z and 1710217z (Jun 20). This anomaly resulted in the loss of 44 frames of SSR data. * On day 171 (Jun 20), during the DSS-34 support for Behind, turbo decoder lock was lost briefly at 2302z. SSR pointers were repositioned and all SSR data were received. * On day 172 (Jun 21), during the DSS-25 support for Behind, the transmitter tripped off at 1532z. The subsequent transition from 2-way to 1-way resulted in the loss of 599 frames of SSR data. To avoid further data loss, MOps requested to remain 1-way for the remainder of the track. Later in the support, telemetry lock was lost from 2129z through 2143z due to an anomaly with the downlink channel control processor. These anomalies resulted in a total loss of 915 frames of data. * The average daily SSR playback volume during the week was 3.6 gigabits for Ahead, and 4.1 gigabits for Behind. * The current HGA temperature on Ahead is 106 degrees, at an SPE angle of 9.5 degrees, and continues to ramp up. The same temperature on Behind is 109 degrees, at an angle of 8.2 degrees, and is leveling off. The goal is to keep these temperatures below 125 degrees. The thermal modeling results have been received. These line up well with the Behind measurements, but the predictions for Ahead are higher than currently measured, and would call for corrective action about a month earlier than scheduled. Since the Ahead results seem to be on the conservative side, no changes in the schedule are currently anticipated. Week 26 (Jun 23-29) * Fault protection rules version 2.3.14 were written to EEPROM on Ahead yesterday (Jun 23). Also, the EA mode bypass was selected. * MOPS macros version 1.1.21 and data handling parameters 1.1.7 will be written to EEPROM on Ahead on Friday, Jun 27. * The 20th HGA calibration for Ahead is scheduled to start at 1:30 UT on Friday, Jun 27. The SPE angle is 9.4 degrees, which is safe for the calibration to continue. The normal +/- 0.5 degree rolls and HGA slews will be carried out. * Mission operations spacecraft testing readiness review Thursday Jun 26 for Ahead, in preparation for the solar conjunction operations test Jul 7-13. * Telemetry lock was lost for several minutes during the station 55 pass for Ahead this morning (Jun 24). * The station 14 transmitter was declared red before the Behind pass yesterday (Jun 23), and the track was carried out as downlink only. The duration of the pass was shortened by 2 hours to allow the transmitter to be repaired. * Ahead has 11 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Thursday, Jun 26 (D43), Friday, Jun 27 (D63, D14 at 720 kbps), and Saturday, Jun 28 (D63 at 720 kbsp). The following passes will be carried out at 160 kbps: Saturday, Jun 28 (D25), and Sunday, Jun 29 (D65). * Behind has 11 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Jun 23 (D14 at 720 kbsp), Tuesday, Jun 24 (D43 at 720 kbps), and Wednesday, Jun 25 (D63). The following passes will be carried out at 160 kbps: Tuesday, Jun 24 (D55), Thursday, Jun 26 (D65), Friday, Jun 27 (D55), and Saturday, Jun 28 (D55). The station 26 pass on Saturday, Jun 28, will be carried out at 240 kbps. Week 27 (Jun 30-Jul 6) * July 4 is the Independence Day holiday. * The 64th momentum dump on Behind will be carried out on Wednesday, Jul 2, with ignition at 20:00 UT. * Solar conjunction testing on the Ahead spacecraft will start Sunday, Jul 6. A detailed timeline will be sent out. On Sunday, at 18:00 UT, the instruments will be powered off, and the SSR will be played back until empty. This will be followed by reconfiguring the SSR for solar conjunction. Near the end of the track, the HGA angle bias will be loaded for the next track. * Ahead has 12 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Jun 30 (D63 at 720 kbps), Tuesday, Jul 1 (D43 at 720 kbps), Thursday, Jul 3 (D14), Saturday, Jul 5 (D43 at 720 kbps, D43), and Sunday, Jul 6 (D63). The following passes will be carried out at 160 kbps: Wednesday, Jul 2 (D54), Friday, Jul 4 (D55), and Sunday, Jul 6 (D25). * Behind has 10 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Jun 30 (D14 at 720 kbps), Tuesday, Jul 1 (D63), Wednesday, Jul 2 (D14), Thursday, Jul 3 (D14 at 720 kbps), and Friday, Jul 4 (D14 at 720 kbps). The station 54 pass on Saturday, Jul 5, will be carried out at 160 kbps. The following station 26 passes will be carried out at 240 kbps: Saturday, Jul 5, and Sunday, Jul 6. Week 28 (Jul 7-13) * Behind will reach perihelion on Jul 9. System momentum will be high, and the SECCHI stepped calibration roll will be delayed by 1-2 weeks. * Behind has 8 passes during the week, and overall coverage is nominal. No 70 meter passes are scheduled during the week. * Solar conjunction testing will be continued on the Ahead spacecraft during the week. On Monday, Jul 7, the Ahead spacecraft will be on the first side lobe. The telemetry rates should be 10 kbps downlink, and 500 bps uplink. * The 69th momentum dump on Ahead will be conducted at 09:00 UT while the HGA is on the first side lobe. The momentum will be adjusted to a lower setting than usual, 8 N-m-s, as will be done during solar conjuction. * After the momentum dump, the Ahead spacecraft will be commanded into a reset at 09:45 UT. It will then be at a data rate of 633 bps downlink, and 125 bps upload, and will come up on the HGA second side lobe. No more commands will be sent up to the spacecraft for the next three days to simulate the situation during conjunction. * On Wednesday, Jul 9, a time-tagged command will start the Ahead spacecraft rolling. It will then cycle through the antennas, starting with the -Z LGA. After 12 hours it will switch to the +Z LGA. The telemetry rate at this point will be 12 bps downlink, 28 bps uplink. * On Thursday, Jul 10, at 09:45 UT, the Ahead spacecraft will autonomously reset after not having received any commands for 3 days. It will continue to rotate. * A time-tagged command will put the Ahead spacecraft back into three-axis stabilized mode prior to the second DSN support. This will be followed by a test of the 1 degree HGA off-point configuration. The telemetry rate on the 70 meter station will be 360 kbps downlink, and 2 kbps uplink. * Ahead spacecraft recovery will start immediately after the 1 degree HGA off-point test. The SSR will be played back, and then reconfigured back into operational mode. Nominal SSR playback will be carried out after that. The HGA will be returned back to nominal pointing for passes starting Saturday, Jul 12. * Instrument recovery will start on Saturday, Jul 12, and continue through the weekend. There's a chance that instrument recovery could start as early as Friday, Jul 11, at 05:30 UT, but the schedule is very tight. ESA passes have been added on Monday and Tuesday of the following week to assist with instrument recovery. The instrument teams will be kept informed as the schedule progresses. * Overall, Ahead has 11 passes during the week, with 8 70 meter passes, and 3 34 meter passes. Week 29 (Jul 14-20) * On Sunday, Jul 15, is the 29th SECCHI Step Calibration on Behind at 0435z for perihelion. * On Sunday, Jul 15, the 20th HGA calibration on Behind will be carried out at 13:00 UT, during the station 63 pass. The SPE angle is 8.8 degrees, which is safe for carrying out the calibration. * Ahead has 13 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Thursday, Jul 17 (D43 at 720 kbps), Friday, Jul 18 (D63), Saturday, Jul 19 (D43 at 720 kbps), and Sunday, Jul 20 (D14 at 720 kbps). The following passes will be carried out at 160 kbps: Tuesday, Jul 15 (D55), Wednesday, Jul 16 (D65), Thursday, Jul 17 (D55), Saturday, Jul 19 (D55 and D15), and Sunday, Jul 20 (D65). ESA Malargue passes are scheduled for Monday and Tuesday, Jul 14-15. * Behind has 10 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Jul 14 (D63), Tuesday, Jul 15 (D63 at 720 kbps), Friday, Jul 18 (D63 at 720 kbps), and Saturday, Jul 19 (D14). The following passes will be carried out at 160 kbps: Wednesday, Jul 16 (D55), Thursday, Jul 17 (D45 and D54), Friday, Jul 18 (D45), Saturday, Jul 19 (D25) and Sunday, Jul 20 (D55). Week 30 (Jul 21-27) * On Thursday, Jul 24, a 3 hour project interface test with the new 34 meter station D35 at Canberra will be carried out. * Ahead has 10 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Tuesday, Jul 22 (D63 at 720 kbps), Wednesday, Jul 23 (D14), Friday, Jul 25 (D14 at 720 kbps), Saturday, Jul 26 (D43), and Sunday, Jul 27 (D14 at 720 kbps). The following passes will be carried out at 160 kbps: Monday, Jul 21 (D54), Thursday, Jul 24 (D55), Saturday, Jul 26 (D54), and Sunday, Jul 27 (D55). * Behind has 12 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Jul 21 (D43 at 720 kbps and D63), Tuesday, Jul 22 (D14 at 720 kbps), Wednesday, Jul 23 (D14 at 720 kbps), Friday, Jul 25 (D63), and Saturday, Jul 26 (D14 at 720 kbps). The following passes will be carried out at 160 kbps: Thursday, Jul 24 (D54), Friday, Jul 25 (D24), Saturday, Jul 26 (D55), and Sunday, Jul 27 (D54). COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 26: M Jun 23 (174) T Jun 24 (175) W Jun 25 (176) T Jun 26 (177) Ahead: HGA calibration, 1:30 UT Ahead: MOps Readiness for S/C Testing Review F Jun 27 (178) S Jun 28 (179) S Jun 29 (180) ------------------------------------------------------------------------------- Scheduled activities for Week 27: M Jun 30 (181) T Jul 01 (182) W Jul 02 (183) Behind: Momentum dump, 20:00 UT T Jul 03 (184) F Jul 04 (185) Independence Day S Jul 05 (186) S Jul 06 (187) Ahead: Turn instruments off, 18:00 UT Notes: * Solar conjunction operations test on Ahead, Jul 6-12. All science instruments will be off during this test. ------------------------------------------------------------------------------- Scheduled activities for Week 28: M Jul 07 (188) Ahead: Momentum dump using first side lobe, 09:00 UT Ahead: Command s/c reset, 09:45 UT, up on second side lobe T Jul 08 (189) W Jul 09 (190) Ahead: Start spacecraft rotation via time-tagged command Behind: Perihelion T Jul 10 (191) Ahead: Autonomous reset, 09:45 UT Ahead: Stop rotating, 19:45 UT, recover back to HGA +1 degree F Jul 11 (192) Instrument SSR partitioning and real-time telemetry rates due S Jul 12 (193) Ahead: Back to nominal HGA pointing. Power on instruments. S Jul 13 (194) Ahead: Continue instrument recovery Notes: * Solar conjunction operations test on Ahead, Jul 6-12. All science instruments will be off during this test. Instrument power on may start as soon as Friday, Jul 11. ------------------------------------------------------------------------------- Scheduled activities for Week 29: M Jul 14 (195) T Jul 15 (196) Behind: SECCHI stepped calibration roll, 04:35 UT Behind: HGA calibration, 13:00 UT W Jul 16 (197) T Jul 17 (198) F Jul 18 (199) S Jul 19 (200) S Jul 20 (201) Notes: * Continuation of instrument power on activities through the week, as needed. ------------------------------------------------------------------------------- Scheduled activities for Week 30: M Jul 21 (202) T Jul 22 (203) W Jul 23 (204) T Jul 24 (205) Project interface test with the new 34 meter station D35 F Jul 25 (206) S Jul 26 (207) S Jul 27 (208) ------------------------------------------------------------------------------- Upcoming events: 2014: * Aug 5 Ahead: HGA on main lobe, offpoint 1 degree * Aug 14 Ahead: Solar Conjunction Readiness Review * Aug 20 Ahead: Instrument power down * Aug 23 Ahead: HGA on 1st side lobe * Sep 07-Nov 15 Behind: Passage of Comet Siding Spring through HI2-B * Sep 18 Behind: MOps Readiness for S/C Testing Review * Sep 29-Oct 6 Behind: Test of solar conjunction operations * Sep 21 MAVEN arrival at Mars * Oct 17 Behind: Comet Siding Spring encounter with Mars * Oct 20 Ahead: Instrument power on * Oct 23 Behind: Solar Conjunction Readiness Review * Nov 10 Ahead: HGA on 2nd side lobe * Dec 1 Behind: HGA on 1st side lobe 2015: * Jan 6 Behind: HGA on 2nd side lobe * Jan 20 Behind: Instrument power down * Jan 22 - Mar 23 Behind: Spacecraft behind Sun * Mar DAWN - Ceres arrival * Mar 22 Ahead: Instrument power down * Mar 24 - Jul 07 Ahead: Spacecraft behind Sun * Mar 30 Behind: Instrument power on * Apr 25 Behind: HGA on 1st side lobe * Jul DAWN - End of nominal mission * Jul 8 Behind: HGA on 2nd side lobe * Jul 14 Ahead: Instrument power on * Sep 24 Ahead: HGA on 1st side lobe * Nov 20 Behind: HGA on 1st side lobe * Dec 29 Ahead: HGA on main lobe, offpoint 1 degree Ahead: SSR playback and reconfiguration, S/C checkout * Dec 31 Ahead: Instrument recommissioning 2016: * Jan 2 Behind: HGA on main lobe Behind: SSR playback and reconfiguration, S/C checkout * Jan 5 Behind: Instrument recommissioning * Jan 27 Both: HGA calibration * Feb 19 Ahead: HGA on main lobe * Mar 16 Both: Post Solar Conjunction Assessment Review * 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