STEREO Weekly Meeting Minutes for 2015-10-13 (Week 42) ANNOUNCEMENTS ------------- * External connectivity to the MOC will be interrupted on Wednesday, Oct 21, for RAID array updates. This will occur during a 7 hour window starting at 17:00 UT. 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 41 (Oct 5-11) * There were no ground anomalies during the week. * 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 8.6 degrees and increasing, with respect to the spacecraft-Sun line. * On day 281 (Oct 8), the 3rd uplink array test for STEREO using DSS-24 and 25 was successfully conducted by the DSN. This test consisted of two 34m stations, each with a 20 kW transmitter using the HGA 1st side lobe with the Ahead observatory with the MOC sending no-op commands. An approximately 6 dBm increase in received signal power was demonstrated, as compared to one 34m uplink, at the spacecraft with all 30 no-op commands being received correctly using the 7.8125 bps uplink rate. * This week, data for the following days was played back from the C&DH routine SSR partition playback: 2015-276-16:43:17z through 2015-284-06:16:45z * 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 91 Mbits during this week. * Preparations for recovering the Behind spacecraft with testing on Ahead continue. The next uplink array test is scheduled for Nov 19, with an 80 kW and 20 kW station arrayed together, with commands being sent. In January, the fifth uplink array test will include segmented frequency acquisition. In February, the testing will be extended to using three stationed arrayed together, one at 80 kW uplink power, and the other two at 20 kW uplink power. At present, the only stations which can be used for uplink array activities are stations 24, 25, and 26 at Goldstone. They're all right next to each other. A previous test with arraying a 70 meter and a 34 meter together was not promising--it was concluded that the distance between them was not known well enough. Station 26 is currently the only DSN station with an 80 kW transmitter; eventually, there will be one at each site. Week 42 (Oct 12-18) * Ahead starts the week at an SPE angle of 5.4 degrees, on the first side lobe, with IMPACT begin prime. * Ahead has 15 passes during the week, with seven passes at 10 kpbs, and eight passes at 633 bps, with overall space weather coverage of 34%. Two ESA passes are scheduled during the week. * Behind starts the week at an SPE angle of 2.1 degrees. There will be no passes for Behind during the week. 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. * Five ESA tracks are scheduled during the week. * Internet connectivity to the MOC will be interrupted on Wednesday, Oct 21. See the announcement above for details. * 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 44%. * 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. * 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 11 passes during the week, with seven passes at 10 kbps, and four passes at 633 bps, with overall space weather coverage of 22%. * 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 short 2 hours during the week, on Tuesday, Wednesday, and Saturday. 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. * 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. 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. * 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) * SECCHI raised a question about the resumption of full space weather beacon telemetry on Monday, Nov 16. The MOC confirmed that the telemetry allocation to the instruments will revert back to the full 633 bps--there will be no spacecraft housekeeping in the spaceweather stream. * The MOC requested that the instrument teams, particularly SECCHI, hold off on resuming normal science operations until Tuesday, Nov 17, to assist with the SSR reconfiguration. * The nominal track time 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 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 IMPACT team expressed interest in using the ESA Malargue track on Tuesday, Nov 17, to start the process of powering on the SWEA. * Tracks will be staffed between Monday and Friday. The times available for instrument commanding are in the presentation. * 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. * Ahead has 9 passes during the week, with five passes at 360 kbps, three passes at 240 kbps, and one pass at 30 kbps. Overall coverage is short 4.6 hours between Tuesday-Friday. * 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) * 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. * 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. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 42: M Oct 12 (285) T Oct 13 (286) W Oct 14 (287) T Oct 15 (288) F Oct 16 (289) S Oct 17 (290) S Oct 18 (291) 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 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) T Nov 10 (314) Ahead: HGA on main lobe, offpoint 1 degree, 240 kbps Ahead: 30 kbps on 34 meter stations Ahead: Resume space weather broadcast to NOAA stations W Nov 11 (315) T Nov 12 (316) F Nov 13 (317) S Nov 14 (318) S Nov 15 (319) 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. * No tracks for Behind due to superior solar conjunction. ------------------------------------------------------------------------------- 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 Ahead: Uplink array test (DSS-25 & 26) F Nov 20 (324) S Nov 21 (325) 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. ------------------------------------------------------------------------------- Upcoming events: Behind events are contingent on recovering the spacecraft. 2015: * Nov 30 Ahead: HGA on main lobe, riding soft stop, 480 kbps Ahead: 120 kbps on 34 meter stations Behind: Resume Behind recovery efforts * Dec 2 Ahead: Begin No Gyro Operations (NGO) Ahead: First NGO momentum dump * 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 Behind: SSR playback and reconfiguration, S/C checkout * 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