STEREO Weekly Meeting Minutes for 2014-06-10 (Week 24) 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 23 (Jun 2-8) * On day 154 (Jun 3), during the DSS-15 support for Ahead, turbo decoder lock was lost intermittently between 1648z and 1649z due to elevation encoder glitches at the station. This anomaly resulted in the loss of 827 frames of SSR data. See DR #G115078 for more information. * On day 156 (Jun 5), during the DSS-45 support for Ahead, no real-time telemetry, commanding, or monitor data were available for the 4.1 hour duration of the track due to the JPL core router going down. All SSR data were later received. See DR #N109589 for more information. * On day 154 (Jun 3), the 68th momentum dump on Ahead was executed successfully at 1730z, which imparted a delta V of 0.0871 m/sec. * On day 156 (Jun 5), the G&C parameters, version 1.3.0, release was loaded to EEPROM on Ahead in preparations for solar conjunction testing. * On day 158 (Jun 7), an LGA calibration test on Ahead was executed successfully at 1450z through 1920z during the DSS-14 support to characterize the performance of both LGA antennas in preparations for solar conjunction. The test rotated the AHEAD observatory about the S/C sun line at 5 degrees/minute for two revolutions, one for each LGA, using the emergency data rates. RF performance is being analyzed. The times for the actual roll were 16:20-19:20 UT. Initial results are as expected, with the performance right on the fringe for about 60-90 degrees in roll. * On day 155 (Jun 4), during the DSS-45 support for Behind, real-time telemetry, commanding, and monitor data were made available 54 minutes late due to the JPL core router going down. All SSR data were later received. See DR #N109577 for more information. * On day 157 (Jun 6), during the DSS-14 support for Behind, acquisition of signal was 38 minutes late due to an elevation servo at the station. This anomaly resulted in the loss of 1392 frames of SSR data. See DR #G115089 more information. * On day 158 (Jun 6), during the DSS-26 support for Behind, the transmitter tripped off-line at 1900z due to a microwave interlock anomaly. This anomaly resulted in the loss of 1932 frames of SSR data. As all commanding objectives had been met, the remainder of the track was telemetry only. See DR #G115094 more information. * On day 154 (Jun 3), the 63rd momentum dump on Behind was executed successfully at 2300z, which imparted a delta V of 0.0655 m/sec. * On day 158 (Jun 7), the SECCHI instrument on Behind reset at 15:00:16z. The SECCHI team reconfigured the instrument to operational mode at 1649z. This was the 22nd reset of SECCHI on the Behind spacecraft. * The average daily SSR playback volume during the week was 4.4 gigabits on Ahead, and 4.1 gigabits on Behind. * The SECCHI partition on Behind reached 100% full for a period on Jun 7. This is a result of the moving of the pointers back during the station 14 pass on Jun 6. Week 24 (Jun 9-15) * Station 14 was offline for the planned Ahead pass on Monday, Jun 9. The pass was switched to station 26 at a lower data rate. Station 14 is back online, but has occasional encoder glitches which affect the margin. * C&DH version 3.2.4 was written to EEPROM copy 2 on Ahead this morning. This is the version that the spacecraft has been operating on all along via patches to the original launch version. Copy 2 will be tested in July. If successful, it will be written to copy 1. * A test of the HGA side lobes on Ahead will be conducted early on Friday, Jun 13, during the station 63 pass. An ESA Malargue support has been added later in the day to make up for the lost telemetry time. This test will explore what telemetry rates can be achieved. In the first side lobe, at around 3.2 degrees, a rate of 10 kbps downlink and 500 bps uplink is expected. In the second side lobe, at around 6.1-6.2 degrees, a rate of 3 kbps downlink, and 125 bps uplink is expected. The normal uplink rate is 2 kbps. * Ahead has 14 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Jun 9 (D14 at 720 kbps), Friday, Jun 13 (D63), and Saturday, Jun 14 (D63 at 720 kbps). The following passes will be carried out at 160 kbps: Tuesday, Jun 10 (D24), Thursday, Jun 12 (D26), Friday, Jun 13 (D26), and Saturday, Jun 14 (D25). The following station 26 passes will be carried out at 240 kbps: Thursday, Jun 12, and Sunday, Jun 15. An ESA Malarque pass is scheduled for Friday, Jun 13. * Behind has 10 passes during the week, and overall coverage is nominal. 70 meter passes, both at 720 kbps, are scheduled for Monday, Jun 9 (D63), and Wednesday, Jun 11 (D14). The following passes will be carried out at 160 kbps: Tuesday, Jun 10 (D55), Thursday, Jun 12 (D55), Friday, Jun 13 (D55), Saturday, Jun 14 (D54), and Sunday, Jun 15 (D25). Week 25 (Jun 16-22) * Station 14 and 26 tracks on Sunday, Jun 22, were switched between Ahead and Behind for sufficient 70 meter coverage on Ahead. * Ahead has 10 passes during the week, and overall coverage is nominal. 70 meter passes, both at 720 kbps, are scheduled for Saturday, Jun 21 (D43), and Sunday, Jun 22 (D14). The following passes will be carried out at 160 kbps: Thursday, Jun 19 (D55), Friday, Jun 20 (D65), and Saturday, Jun 21 (D65). The following station 26 passes will be carried out at 240 kbps: Wednesday, Jun 18. * Behind has 11 passes during the week, and overall coverage is nominal. 70 meter passes are scheduled for Monday, Jun 16 (D63), and Friday, Jun 20 (D63 at 720 kbps). The following passes will be carried out at 160 kbps: Monday, Jun 16 (D65), Tuesday, Jun 17 (D55), Wednesday, Jun 18 (D55), Thursday, Jun 19 (D54), and Saturday, Jun 21 (D25). The station 26 pass on Sunday, Jun 22, will be carried out at 240 kbps. Week 26 (Jun 23-29) * MOPS macros version 1.1.21 and fault protection rules version 2.3.14 will be written to EEPROM on Ahead on Monday, Jun 23. * Mission operations spacecraft testing readiness review Thursday Jun 26 for Ahead, in preparation for the solar conjunction operations test Jul 7-13. * 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, 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 has 8 passes during the week, and overall coverage is nominal. No 70 meter passes are scheduled during the week. * 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. * 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 while the HGA is on the first side lobe. The momentum will be adjusted to a lower setting than usual, as will be done during solar conjuction. * After the momentum dump, the Ahead spacecraft will be commanded into a reset. 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, 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 operation mode. * 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, but the schedule is very tight. ESA passes have been added on Monday and Tuesday of the following week to assist with instrument recovery. Other * The station 45 maser is still red, lowering the sensitivity by 2 dB. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 24: M Jun 09 (160) T Jun 10 (161) W Jun 11 (162) T Jun 12 (163) F Jun 13 (164) Ahead: HGA side-lobe test during station 63 pass S Jun 14 (165) S Jun 15 (166) ------------------------------------------------------------------------------- Scheduled activities for Week 25: M Jun 16 (167) T Jun 17 (168) W Jun 18 (169) T Jun 19 (170) F Jun 20 (171) S Jun 21 (172) S Jun 22 (173) ------------------------------------------------------------------------------- Scheduled activities for Week 26: M Jun 23 (174) T Jun 24 (175) W Jun 25 (176) T Jun 26 (177) 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) T Jul 03 (184) F Jul 04 (185) Independence Day S Jul 05 (186) S Jul 06 (187) Ahead: Turn instruments off 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 side lobe, command s/c reset 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, recover spacecraft back to HGA F Jul 11 (192) S Jul 12 (193) Ahead: 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. ------------------------------------------------------------------------------- Upcoming events: 2014: * Jul 23 Both: HGA calibration * Aug 5 Ahead: HGA on main lobe, offpoint 1 degree * Aug 14 Ahead: Solar Conjunction Readiness Review * Aug 20 Ahead: Start of solar conjunction operations * Aug 22 Ahead: Rehearse with DSN * 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 23 Behind: Solar Conjunction Readiness Review * Nov 10 Ahead: HGA on 2nd side lobe * Nov 14 Behind: Start of solar conjunction operations * Nov 16 Behind: Rehearse with DSN * Dec 1 Behind: HGA on 1st side lobe 2015: * Jan 3 Behind: HGA on 2nd side lobe * Jan 22 - Mar 23 Behind: Spacecraft behind Sun * Mar DAWN - Ceres arrival * Mar 24 - Jul 07 Ahead: Spacecraft behind Sun * Jul DAWN - End of nominal mission * Aug 25 - Oct 19 Behind: Possible interference from Sun * Sep 24 Ahead: HGA on 1st side lobe * Nov 23 Behind: HGA on 1st side lobe * Dec 28 Ahead: Spacecraft recovery * Dec 29 Ahead: HGA on main lobe, offpoint 1 degree * Dec 31 Ahead: Instrument turn-on 2016: * Jan 12 Behind: HGA on main lobe * Jan 18 Behind: Instrument turn-on * 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