STEREO Weekly Meeting Minutes for 2015-10-20 (Week 43) ANNOUNCEMENTS ------------- * The MOC RAID array updates previously scheduled for tomorrow (Oct 21) have been tentatively rescheduled for Oct 29, during an 8 hour window starting at 20:00 UT. There are no tracks scheduled during this time. External connectivity to the MOC will be interrupted during these updates. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * Ahead is operating nominally on the first side lobe. * There are currently no communications with the Behind spacecraft. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 42 (Oct 12-18) * On day 286 (Oct 13), during the DSS-26 support for Ahead, at 0003z, one SECCHI instrument command packet was not received correctly. At the time, station elevation was approximately 16 degrees and decreasing. * On day 287 (Oct 14), during the DSS-14 support for Ahead, turbo decoder lock was lost briefly at 1621z and again at 1705z. This anomaly resulted in the loss of two frames of real-time data. * The Ahead observatory operated nominally during this week on the 1st side lobe of the HGA to prevent overheating of the HGA feed assembly which was at 110 degrees C and decreasing with the HGA angle at 8.7 degrees and increasing, with respect to the spacecraft-Sun line. * This week, data for the following days was played back from the C&DH routine SSR partition playback: 2015-284-06:16:45z through 2015-290-06:59:43z Specifically, this partition contains spacecraft bus data for science analysis and instrument status, i.e., attitude history, instrument thermal interface temperatures, heater performance, etc., which are used to create the attitude history and converted spacecraft housekeeping data products. * The following days have not played back yet: 071 through 133 = 63 days (inclusive) 146 through 231 = 86 days (inclusive) Total = 149 days This partition’s write pointer is being monitored to ensure that these days are not overwritten, which is currently predicted to do so after returning to the HGA main lobe on or about Nov 13th. * Once on the HGA main lobe, the in-situ instrument space weather science SSR data along with the spacecraft housekeeping data will be downlinked twice and verified before the SSR is reconfigured to resume nominal daily science operations. * The average daily science data return for Ahead, while operating on the 1st side lobe of the HGA, was 90 Mbits during this week. * Behind recovery operations will resume Nov 30. There will be 3 tracks per week, with the first two tracks devoted to powering up the battery, and the third track to enabling the transmitter. The previous (third) DNS uplink array test on Oct 8 tested combining two transmitters on stations 24 and 25, both at 20 kW uplink power, which boosted the signal by about 6 dB. The fourth uplink array test is scheduled for Nov 19, and will combine an 80 kW and a 20 kW transmitter. Week 43 (Oct 19-25) * Ahead starts the week at an SPE angle of 5.6 degrees, on the first side lobe, with SWAVES being prime. * Sun, Oct 25, will mark the 9th anniversary of STEREO's launch. * Ahead has 18 passes during the week, with seven passes at 10 kbps, and eleven passes at 633 bps, with overall space weather coverage of 46%. * Behind starts the week at an SPE angle of 2.2 degrees. There will be no passes for Behind during the week. Week 44 (Oct 26-Nov 1) * Ahead starts the week at an SPE angle of 5.7 degrees, on the first side lobe, with IMPACT being prime. * MOC RAID updates are tentatively scheduled for Thursday, Oct 29. See the announcement above for details. * The commands for the momentum dump on Monday, Nov 2, will be loaded on Friday, Oct 30. * Daylight savings time ends in the U.S. on Sunday, Nov 1. * Ahead has 12 passes during the week, with seven passes at 10 kbps, and five passes at 633 bps, with overall space weather coverage of 27%. * Behind starts the week at an SPE angle of 2.4 degrees. There will be no passes for Behind during the week. Week 45 (Nov 2-8) * Ahead starts the week at an SPE angle of 5.9 degrees, on the first side lobe, with SWAVES being prime. * The 81st momentum dump on Ahead will be carried out on Monday, Nov 2, with ignition at 17:30 UT. IMU-2 will be on during this momentum dump. * Ahead has 8 passes during the week. 70 meter coverage is now nominal.. There are seven passes at 10 kbps, and one pass at 633 bps, with overall space weather coverage of 13%. * Behind starts the week at an SPE angle of 2.6 degrees. There will be no passes for Behind during the week. Week 46 (Nov 9-15) * Ahead starts the week still on the first side lobe, with IMPACT being prime. * A detailed schedule for the events during the week has been sent out, including command windows for the instruments. * Temporary macros will be loaded to RAM on Monday, Nov 9, to allow higher real-time rates for the instruments during the week. * In spite of the increase in the telemetry rate, the instruments will remain at their first-side-lobe rates throughout the week, until the SSR partitions are reconfigured on Monday, Nov 16. * At the end of the last pass on Monday, Nov 9, the HGA will be switched to the main lobe, with a 1 degree offset. Immediately following this pass ending at 21:55 UT the NOAA antenna partners should be able to lock onto the space weather beacon telemetry. At this point the nominal telemetry rate will be 240 kbps on 70 meter stations, or 30 kbps on 34 meter stations. However, if a 70 meter pass is at high elevation throughout the pass, the telemetry rate can be increased to 360 kbps, which will be the case for all the passes Tuesday through Sunday. * Starting Tuesday, Nov 10, the uplink rate will increase to 2000 bps for all stations. * On Tuesday, Nov 10, the SSR pointers will be moved to start reading out the SSR. The SSR partitions will be read out at least twice between Tuesday and Sunday. * On Sunday, Nov 15, the original macros will be reloaded into RAM to prepare for switching back to nominal operations mode. SECCHI will also perform some real-time commanding to reduce their telemetry rate. This will result in no images being taken from some time before 23:20 UT on Nov 15 until sometime on Nov 16 or 17. The spacecraft will not switch to space weather mode at the end of the pass to give the buffers a chance to empty out. * Ahead has 9 passes during the week, with one pass at 10 kbps, seven passes at 360 kbps, and one pass at 633 bps (on Monday, Nov 9). * Behind starts the week at an SPE angle of 2.9 degrees. There will be no passes for Behind during the week. Week 47 (Nov 16-22) * The MOC requested that the instrument teams, particularly SECCHI, hold off on reconfiguring back to normal science operations until Tuesday, Nov 17, to assist with the SSR reconfiguration. The first opportunity for commanding on Tuesday will be at 08:50 UT. * On Monday, Nov 16, during the station 63 pass for Ahead starting at 10:45 UT, the SSR will be emptied and repartitioned. Updated data handling and MOPS macros will be loaded into RAM. * Normal science operations will resume on Tuesday, Nov 17, starting with the station 63 pass for Ahead. The IMPACT SWEA and STE instruments will be powered on, and the SECCHI and SWAVES instruments will be allowed to upload schedules. * The fourth uplink array test will be carried out on Thursday, Nov 19. This will involve arraying together two stations, one at 80 kW transmitter power, and the other at 20 kW. * 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 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. * SECCHI asked for a time at which they could start writing to the SSR. The MOC replied that they will know better on Nov 16, but otherwise consider it to be no earlier than 08:50 UT on Nov 17. Week 48 (Nov 23-29) * On Monday, Nov 23, G&C parameter set 1.3.4 will be written to EEPROM. * A SECCHI stepped calibration roll is tentatively scheduled for Tuesday, Nov 24, starting at 16:00 UT. This roll requires management approval because of the use of IMU-2. * 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) * The nominal rate on Ahead for 70 meter stations will increase to 480 kbps. * On Monday, Nov 30, data handing and macro parameters will be written to EEPROM. * Ahead has 7 passes during the week, all at 480 kbps, and overall coverage is nominal. * Behind recovery operations resume on Monday, Nov 30. There will be three 4.5 hour passes over three days each week. The first two passes, both on Monday, Nov 30, will attempt to power up the battery, and the third pass, on Wednesday, Dec 2, will attempt to command on the transmitter. Behind starts the week at an SPE angle of 3.9 degrees. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 43: M Oct 19 (292) T Oct 20 (293) W Oct 21 (294) T Oct 22 (295) F Oct 23 (296) S Oct 24 (297) S Oct 25 (298) 9th STEREO launch anniversary Notes: * Ahead operating on the first side lobe, in SWAVES-prime mode. * No tracks for Behind due to superior solar conjunction. ------------------------------------------------------------------------------- Scheduled activities for Week 44: M Oct 26 (299) T Oct 27 (300) W Oct 28 (301) T Oct 29 (302) F Oct 30 (303) S Oct 31 (304) S Nov 01 (305) Daylight savings time ends in U.S. Notes: * Ahead operating on the first side lobe, in IMPACT-prime mode. * No tracks for Behind due to superior solar conjunction. ------------------------------------------------------------------------------- Scheduled activities for Week 45: M Nov 02 (306) Ahead: Momentum dump, 17:30 UT T Nov 03 (307) W Nov 04 (308) T Nov 05 (309) F Nov 06 (310) S Nov 07 (311) S Nov 08 (312) Notes: * Ahead operating on the first side lobe, in SWAVES-prime mode. * No tracks for Behind due to superior solar conjunction. ------------------------------------------------------------------------------- Scheduled activities for Week 46: M Nov 09 (313) Ahead: Space weather beacon on NOAA stations resumes 21:55 UT T Nov 10 (314) Ahead: HGA on main lobe, offpoint 1 degree, 240 kbps Ahead: 30 kbps on 34 meter stations W Nov 11 (315) T Nov 12 (316) F Nov 13 (317) S Nov 14 (318) S Nov 15 (319) Ahead: No space weather broadcast following station 43 pass Notes: * Ahead starts the week on the first side lobe, in IMPACT-prime mode. The instruments will continue to produce telemetry at the first-side-lobe rates through the week, until the SSR partitions are reconfigured on Monday, Nov 16. * SECCHI will stop taking images near the end of the day on Nov 15 to assist in the SSR reconfigurations. Images will resume sometime on Nov 16 or 17. * No tracks for Behind due to superior solar conjunction. ------------------------------------------------------------------------------- Scheduled activities for Week 47: M Nov 16 (320) Ahead: HGA on main lobe, riding soft stop, 360 kbps 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: 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) Ahead: SECCHI stepped calibration roll, 16:00 (TBC) 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 T Dec 03 (337) F Dec 04 (338) S Dec 05 (339) S Dec 06 (340) ------------------------------------------------------------------------------- Upcoming events: Behind events are contingent on recovering the spacecraft. 2015: * Dec 14 Ahead: 160 kbps on 34 meter stations * Dec 28 Ahead: HGA on main lobe, riding soft stop, 720 kbps * 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 * Apr Behind: Switch downlink rate to 240 kbps 2020: * May Behind: Switch downlink rate to 360 kbps * Jun Ahead: Switch downlink rate to 360 kbps * Jun Behind: Switch downlink rate to 480 kbps * Sep Ahead: Switch downlink rate to 480 kbps 2021: * Jul Behind: Switch downlink rate to 720 kbps * Aug Ahead: Switch downlink rate to 720 kbps