STEREO Weekly Meeting Minutes for 2015-11-17 (Week 47) ANNOUNCEMENTS ------------- INSTRUMENT and SPACECRAFT STATUS -------------------------------- * Ahead is operating nominally on the main lobe of the high gain antenna with a one degree offset. * There are currently no communications with the Behind spacecraft. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 46 (Nov 9-15) * On day 317 (Nov 13), during the DSS-63 support of Ahead, turbo decoder lock was lost at 1132z. This anomaly resulted in the loss of one frame of SSR data. * The Ahead observatory operated nominally during this week resuming operations on the HGA main lobe riding along a one degree offset to prevent overheating of the HGA feed assembly which was at 119 degrees C and decreasing with the HGA angle at 7.1 degrees and increasing, with respect to the spacecraft-Sun line. The 15 months of in-situ instruments science data on the SSR have been played back twice and all science data has been received. NOAA antenna partners will gradually be able to close the RF link on the space weather broadcast. On day 321, November 17th, instruments will begin reconfiguration for resuming nominal daily science data return. * On day 312 (Nov 8), during the DSS-63 support of Ahead, temporary macro 237 was loaded to C&DH RAM to continue to provide 10 kbps real-time science data and increase SSR playback ratio to 35 during the 360 kbps downlink supports. * On day 313 (Nov 9), during the DSS-26 support, at 2000z the STEREO Ahead observatory resumed operations using the main lobe of the HGA, resulting in a 13 dB signal increase. The HGA soft stop was set to 7.1 degrees and the HGA will be riding along a one degree offset from the center of the main lobe till day 364, December 30th to keep the HGA feed assembly cool. From now on, the NOAA antenna partners will gradually be able to close the RF link on the space weather broadcast in between DSN or ESA tracks. * On day 314 (Nov 10), during the DSS-14 support of Ahead, moved SSR read pointers for IMPACT, PLASTIC, SWAVES, and G&C partitions to one and began SSR playback of recorded data since commencing HGA side lobe operations on day 2014-231, August 19th, 2014. * On day 316 (Nov 12), during the DSS-43 support, began second playback of SSR data by moving SSR read pointers for IMPACT, PLASTIC, SWAVES, and G&C partitions to one and C&DH partition to 882740. * On day 319 (Nov 15), during the DSS-43 support, the original macro 237 was loaded to C&DH RAM to restore the real-time telemetry rates to the following prime science allocations during the 360 kbps downlink supports. - IMPACT & PLASTIC = 3.2 kbps each - SECCHI = 3.6 kbps - SWAVES = 2.2 kbps - Space weather = 0.633 kbps * On day 319 (Nov 14), the space weather broadcast was not available from 2320z through 320-1030z to allow the real-time telemetry queues to empty in preparations for returning the instruments to nominal daily science operations. * Processing status of the in-situ instrument space weather data recorded during the 15 months of side lobe operations: This week, the following days were processed with the associated data products available on the MOC STEREO Data Server and GSFC SSC websites: Day 2014-231 through day 2014-331 (August 19th, through November 27th, 2014). * The average daily science data return for Ahead, with the HGA on the main lobe riding along a one degree offset, was 371 Mbits during week 48 week. * Behind started the week at an SPE angle of 2.9 degrees. There were no passes for Behind during the week. * Q: How long will it take to process all the data from the conjunction period? A: 2015 Jan or Feb are being processed now, so by early next week. There should be an update next week. Week 47 (Nov 16-22) * Ahead starts the week at an SPE angle of 6.2 degrees. * Nominal DSN 70 meter track time coverage will be increased from 3 to 4 hours. * On Monday, Nov 16, during the station 63 pass for Ahead starting at 10:45 UT, the SSR were be emptied and repartitioned. Updated data handling (release 1.1.11) and MOPS macros (release 1.128) were loaded into RAM. The in situ data partitions will be slightly larger than they were before solar conjunction. * Normal science operations will resume on Tuesday, Nov 17, starting with the station 63 pass for Ahead. Later on Tuesday is a ESA Malargüe track good for uploading. The IMPACT SWEA and STE instruments will be powered on, and the SECCHI and SWAVES instruments will be allowed to upload schedules. The SWEA high voltage can begin to be ramped up. * All passes during the week will be supported at the MOC. Since the uplink rate will be 2000 bps, all the instruments should be able to share the uplink. Using the voice loops for coordinating commanding is recommended. * The fourth uplink array test will be carried out on Thursday, Nov 19 with stations 26 and 25. This will involve arraying together two stations, one at 80 kW transmitter power, and the other at 20 kW. There will be no instrument commanding or SSR playback during this pass. * On Thursday, Nov 19, the nominal telemetry rate on the 70 meter stations will be increased to 360 kbps. * A return-to-service track for station 55 is scheduled for Saturday, Nov 21. There will be no instrument commanding or SSR playback during this pass. * Ahead has 10 passes during the week, with six passes at 360 kbps, three passes at 240 kbps, and one pass at 30 kbps. Overall coverage is nominal. * Behind starts the week at an SPE angle of 3.2 degrees. There will be no passes for Behind during the week. Week 48 (Nov 23-29) * Ahead starts the week at an SPE angle of 6.4 degrees, with a nominal 70 meter telemetry rate of 360 kbps. * On Monday, Nov 23, G&C parameter release 1.3.4 will be written to EEPROM and some G&C parameters will be dumped from RAM. * APL will be closed for the Thanksgiving holiday Thursday and Friday, Nov 26-27. * Ahead has 9 passes during the week, all at 360 kbps, and overall coverage is nominal. * Behind starts the week at an SPE angle of 3.5 degrees. There will be no passes for Behind during the week. Recovery operations resume the following week. Week 49 (Nov 30-Dec 6) * Ahead starts the week at an SPE angle of 6.5 degrees, riding the HGA soft stop. * The nominal rate on Ahead for 70 meter stations will increase to 480 kbps on Monday, Nov 30. * On Monday, Nov 30, updated fault protection release 2.3.18 (no gyro operations release) will be written to RAM as well as MOC macro 505. * The 82nd momentum dump for Ahead is scheduled for Dec 2. Since this will be the first momentum dump under no-gyro operations, the dump will be shortened so that the target momentum is zero N-m-s, i.e. about half the normal dump. The telemetry rate will also be reduced to 96 kbps to maintain telemetry lock in case the pointing varies during the dump. * Ahead has 7 passes during the week, all at 480 kbps, and overall coverage is nominal. * Behind starts the week at an SPE angle of 3.9 degrees. * Behind recovery operations resume on Monday, Nov 30. There will be three passes over three days each week. The first two passes, both 4.5 hours, on Monday, Nov 30, and Tuesday, Dec 1, will attempt to power up the battery, and the third pass (4 hours), on Wednesday, Dec 2, will attempt to command on the transmitter. Time has been requested from the Arecibo and Green Bank observatories to listen during the Dec 2 pass. Week 50 (Dec 7-13) * Ahead starts the week at an SPE angle of 6.6 degrees, riding the HGA soft stop, with a nominal 70 meter telemetry rate of 480 kbps. * On Tuesday, Dec 8, C&DH release 1.1.11 and macro parameters 1.1.28 will be written to EEPROM. * A return-to-service track for station 34 is scheduled for Friday, Dec 11, with downlink at 120 kps. There will be no instrument commanding or SSR playback during the track. * Ahead has 10 tracks during the week, eight at 480 kbps, and two at 120 kbps, and overall coverage is short 2.9 hours between Friday to Sunday, Dec 11-13. * Behind starts the week at an SPE angle of 4.3 degrees. Recovery efforts for Behind are scheduled for Thursday-Saturday, Dec 10-12. Week 51 (Dec 14-20) * Ahead starts the week at an SPE angle of 6.8 degrees. * On Monday, Dec 14, the downlink rate for 34 m stations for Ahead will increase to 160 kbps. * Also on Monday, Dec 14, updated fault protection rules 2.3.18 will be written to EEPROM. * Ahead has nine tracks during the week, with seven tracks at 480 kbps, one track at 240 kbps, and one track at 160 kbps. Overall coverage is short 7.9 hours between Monday and Saturday (DOY 348 to 353). No loss of data for the in-situ instruments is anticipated, but SECCHI should plan for the shortfall. * Behind starts week with SPE angle of 4.7 deg. Recovery efforts for Behind are scheduled with three tracks Monday-Thursday, Dec 14-17. Week 52 (Dec 21-27) * The 83rd momentum on Ahead is scheduled for Monday, Dec 21, with ignition at 15:30 UT. This dump is scheduled earlier than usual because the previous momentum dump was short. The telemetry rate will be switched to 96 kbps during the dump to maintain lock. * APL will be closed on Friday, Dec 25, for the Christmas holiday. * Ahead has 10 passes during the week, seven at 480 kbps, and three at 160 kbps. * Behind starts the week at an SPE angle of 5.2 degrees. Recovery efforts for Behind are Thursday-Saturday, Dec 24-26. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 47: M Nov 16 (320) Ahead: SSR playback and reconfiguration Ahead: No SECCHI telemetry 10:00-10:20 UT Ahead: Resume prime science real-time telemetry rates Ahead: End S/C telemetry in space weather broadcast T Nov 17 (321) Ahead: Instrument recommissioning, IMPACT SWEA/STE on W Nov 18 (322) T Nov 19 (323) Ahead: HGA on main lobe, riding soft stop, 360 kbps on 70 m Ahead: Uplink array test (DSS-25 & 26) F Nov 20 (324) S Nov 21 (325) Ahead: Return-to-service test with station 55 S Nov 22 (326) Notes: * After Friday, Nov 20, the Behind spacecraft will be able to operate on the first side lobe after it is recovered. * No tracks for Behind due to superior solar conjunction. ------------------------------------------------------------------------------- Scheduled activities for Week 48: M Nov 23 (327) Ahead: 96 kbps on 34 meter stations T Nov 24 (328) W Nov 25 (329) T Nov 26 (330) Thanksgiving F Nov 27 (331) S Nov 28 (332) S Nov 29 (333) Notes: * No tracks for Behind due to superior solar conjunction. ------------------------------------------------------------------------------- Scheduled activities for Week 49: M Nov 30 (334) Ahead: HGA on main lobe, riding soft stop, 480 kbps Ahead: 120 kbps on 34 meter stations Behind: Resume Behind recovery efforts T Dec 01 (335) W Dec 02 (336) Ahead: Begin No Gyro Operations (NGO) Ahead: First NGO momentum dump, 23:00 UT T Dec 03 (337) F Dec 04 (338) S Dec 05 (339) S Dec 06 (340) ------------------------------------------------------------------------------- Scheduled activities for Week 50: M Dec 07 (341) T Dec 08 (342) W Dec 09 (343) T Dec 10 (344) F Dec 11 (345) Ahead: Return-to-service track with station 34. S Dec 12 (346) S Dec 13 (347) ------------------------------------------------------------------------------- Scheduled activities for Week 51: M Dec 14 (348) Ahead: 160 kbps on 34 meter stations T Dec 15 (349) W Dec 16 (350) T Dec 17 (351) F Dec 18 (352) S Dec 19 (353) S Dec 20 (354) ------------------------------------------------------------------------------- Scheduled activities for Week 52: M Dec 21 (355) Ahead: Momentum dump, 15:30 UT T Dec 22 (356) W Dec 23 (357) T Dec 24 (358) F Dec 25 (359) Christmas S Dec 26 (360) S Dec 27 (361) ------------------------------------------------------------------------------- Upcoming events: Behind events are contingent on recovering the spacecraft. 2015: * Dec 28 Ahead: Main lobe, riding soft stop, 720 kbps (70 m) * Dec 30 Ahead: HGA on main lobe 2016: * Jan 2 Behind: HGA on main lobe, offpoint 1 degree, 240 kbps Behind: Resume space weather broadcast to NOAA stations * Jan 5 Behind: HGA on main lobe, riding soft stop, 360 kbps Behind: SSR playback and reconfiguration * Jan 6 Behind: Instrument recommissioning, IMPACT SWEA/STE on * Jan 9 Behind: HGA on main lobe, riding soft stop, 480 kbps * Jan 11 Behind: HGA on main lobe, riding soft stop, 720 kbps * Jan 12 Ahead: First NGO SECCHI stepped calib. roll (date TBC) Behind: HGA on main lobe * Jan 27 Both: HGA calibration (NGO) * Mar 3 Behind: Resume LGA uplink capability on 70 m DSN * Apr 6 Ahead: Resume LGA uplink capability on 70 m DSN * May 16 Both: Post Solar Conjunction Assessment Review * Jul 5 Juno arrival at Jupiter * Dec Behind: Resume LGA downlink capability on 70 m DSN 2017: 2018: * Mar 5 Ahead: Mercury transit 2019: * Mar Ahead: Switch downlink rate to 240 kbps for 34 meter * Apr Behind: Switch downlink rate to 240 kbps for 34 meter 2020: * May Behind: Switch downlink rate to 360 kbps for 34 meter * Jun Ahead: Switch downlink rate to 360 kbps for 34 meter * Jun Behind: Switch downlink rate to 480 kbps for 34 meter * Sep Ahead: Switch downlink rate to 480 kbps for 34 meter 2021: * Jul Behind: Switch downlink rate to 720 kbps for 34 meter * Aug Ahead: Switch downlink rate to 720 kbps for 34 meter