STEREO Weekly Meeting Minutes for 2018-09-25 (Week 39) ANNOUNCEMENTS ------------- * Four years after the initial loss of communications anomaly with Behind observatory, NASA has directed to cease periodic recovery operations with the last support on October 17, 2018. Additional information can be found at: https://stereo-ssc.nascom.nasa.gov/behind_status.shtml INSTRUMENT and SPACECRAFT STATUS -------------------------------- * Ahead is operating nominally on the main lobe of the high gain antenna. * Behind has transitioned to a monthly schedule to attempt to recover the spacecraft. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 38 (Sep 17-23) * On day 260 (Sept 17), during the DSS-14 support for STEREO-A, the initial receipt of monitor data was delayed for 30 minutes. Also, the station was unable to conduct pre-pass ranging calibrations. A post pass ranging calibration was conducted. These anomalies resulted in the loss of 30 minutes of monitor data. All SSR data was received. * On day 266, (Sept 23) during the DSS-65 support for STEREO-A, no monitor data was received for the duration of the support due to a software issue at the Madrid complex. This anomaly resulted in the loss of 3 hours of monitor data. All SSR data was received. * On day 259 (Sept 16) fine pointing was lost intermittently (~78 times) on STEREO-A beginning at 23:33 UTC through 260 (Sept 17) 22:00 UTC. This occurred when wheel #2 passed through zero speed and remained below the wheel speed avoidance (WSA) bandwidth (+ and - 30.70 rads/sec). Fine pointing stabilized after wheel #2 remained above the WSA bandwidth. G&C is investigating possible mitigations include shortening the WSA computation time and increasing the filter bandwidth to speed convergence. * On day 266 (Sept 23) on STEREO-A the IMPACT IDPU/MAG high power consumption autonomy rule (#64) fired at 11:17:33z. This powered off all of IMPACT and PLASTIC instruments. This is 2nd occurrence on the Ahead spacecraft with last occurrence in September of 2011. On day 267 (Sept 24), the IMPACT IDPU/MAG and SWEA/STE power services were turned on at 18:22 and 19:09 UTC respectively. * The average daily science data return for Ahead was 4.4 Gbits during this week. * Behind recovery track took place on day 264 (Sept 21). During a 2.5 hour 1 kHz battery recovery support with DSS-14, 189 commands were transmitted for battery state of charge recovery. Due to the duration of the support, only 21 of the 36 frequency segments were commanded. * Behind recovery track took place on day 265 (Sept 22). During a 4 hour 1 kHz carrier recovery support with DSS-14, 440 commands were sent for transmitter carrier recovery. No carrier was detected by the DSN station. Due to the duration of the support and the increased commands for each step, only 22 of the 36 frequency segments were commanded. Three commands must be received sequentially to power on the transmitter. * Behind recovery track took place on day 266 (Sept 23). During a 4 hour 1 kHz carrier recovery support with DSS-14, 440 commands were sent for transmitter carrier recovery. No carrier was detected by the DSN station. Due to the duration of the support and the increased commands for each step, only 22 of the 36 frequency segments were commanded. Three commands must be received sequentially to power on the transmitter. Week 39 (Sep 24-30) * September 24th, day 267, there were no uplink, no commands sent, and only one way tracking data with the ESA New Norcia support. * September 24th, day 267, St 14 support for STEREO-A IMPACT instrument recovery began. IMPACT IDPU and SWEA power services turned on. * September 25th, day 268, STEREO-A IMPACT will continue to power up and reconfigure and will turn on the SEP suite of instruments. PLASTIC will turn on instruments and reconfigure. * September 27th, day 270, the first SLE bluebook version 4 testing is scheduled between MOC and station Goldstone for 5 hours. * Ahead has nine passes during the week, and overall coverage is nominal with the addition of an ESA New Norcia pass on Monday, and an ESA Cebreros pass on Thursday. There are six passes at 720 kbps, one pass at 360 kbps, and two passes at 160 kbps. * There are no recovery passes for Behind during the week. Week 40 (Oct 1-7) * On Tuesday, October 2nd, the 113th momentum dump is scheduled for 15:30 UT on Ahead. This will be the 32nd momentum dump that does not use the gyros. It will be carried out during an ESA Malargue pass. * Wednesday, Oct 3rd, test track on ESA Malargue for 4 hours to test the Ahead MOC transition to CCSDS SLE bluebook version 4. * Ahead has eleven passes during the week, and overall coverage is nominal. There are six passes at 720 kbps, two at 360 kbps, and three at 160 kbps. This includes 4.25 hours of ESA New Norcia coverage on Tuesday and the momentum dump on ESA Malargue on Tuesday for 4.25 hours. * There are no recovery passes for Behind during the week. Week 41 (Oct 8-14) * Ahead has eleven passes during the week, and overall coverage is nominal. There are six passes at 720 kbps, two at 360 kbps, one at 240 kbps, and two at 160 kbps. This includes ESA Cebreros passes on Monday and Thursday. * There are no recovery passes for Behind during the week. * Oct 12th Behind reaches perihelion. Week 42 (Oct 15-21) * Wednesday, October 17th, SLE bluebook version 4 test between ESA Cebreros and the MOC for 4 hours. * Ahead has nine passes during the week, and overall coverage is nominal. There are four passes at 720 kbps, two at 360 kbps, and three at 160 kbps. This includes an ESA Cebreros pass on Thursday October 18th. * Search pattern recovery passes for Behind are scheduled for Monday, Oct 15th (battery), and on Tuesday and Wednesday, October 16th and 17th (both carrier). Until further notice, these are the last recovery attempts for Behind. Week 43 (Oct 22-28) * Thursday, Oct 25, is the 12th anniversary of the launch of STEREO. * October 26th, Station 55 is impacted due to maintenance. Have requested an ESA Cebreros pass to replace this coverage. * Ahead has ten passes during the week, and overall coverage is nominal. There are four passes at 720 kbps, two at 360 kbps, two at 240 kbps, and two at 160 kbps. This includes the request for ESA Cebreros pass on Friday. * There are no recovery passes for Behind during the week. Week 44 (Oct 29-Nov 4) * Nov 4th 06:00UTC daylight savings time will end. * Ahead has eight passes during the week, and overall is nominal. There are four passes at 720 kbps, three at 360 kbps, one at 160 kbps. * There are no recovery passes for Behind during the week. Week 45 (Nov 5-Nov 11) * Ahead has thirteen passes during the week. Overall coverage was short. Requested four ESA supports with New Norcia (Tuesday and Friday), Malargue (Wednesday), and Cebreros (Friday), and coverage is probably OK. There are three passes at 720 kbps, two at 360 kbps, one at 240 kpbs and seven at 160 kbps. * There are no recovery passes for Behind during the week. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 38: M Sep 17 (260) T Sep 18 (261) W Sep 19 (262) T Sep 20 (263) F Sep 21 (264) Behind: Recovery track, DSN 14 (1 kHz, battery) S Sep 22 (265) Behind: Recovery track, DSN 14 (1 kHz, carrier) S Sep 23 (266) Behind: Recovery track, DSN 14 (1 kHz, carrier) ------------------------------------------------------------------------------- Scheduled activities for Week 39: M Sep 24 (267) Ahead: IMPACT recovery power up T Sep 25 (268) Ahead: PLASTIC recovery power up W Sep 26 (269) T Sep 27 (270) Ahead: Interface test track with Goldstone F Sep 28 (271) S Sep 29 (272) S Sep 30 (273) ------------------------------------------------------------------------------- Scheduled activities for Week 40: M Oct 01 (274) T Oct 02 (275) W Oct 03 (276) Ahead: Interface test track with ESA Malargue T Oct 04 (277) F Oct 05 (278) S Oct 06 (279) S Oct 07 (280) ------------------------------------------------------------------------------- Scheduled activities for Week 41: M Oct 08 (281) T Oct 09 (282) W Oct 10 (283) T Oct 11 (284) F Oct 12 (285) S Oct 13 (286) S Oct 14 (287) ------------------------------------------------------------------------------- Scheduled activities for Week 42: M Oct 15 (288) Behind: Recovery track, DSN 14 (search pattern, battery) T Oct 16 (289) Behind: Recovery track, DSN 43 (search pattern, carrier) W Oct 17 (290) Behind: Recovery track, DSN 43 (search pattern, carrier) Ahead: Interface test track with ESA Cebreros T Oct 18 (291) F Oct 19 (292) S Oct 20 (293) S Oct 21 (294) ------------------------------------------------------------------------------- Scheduled activities for Week 43: M Oct 22 (295) T Oct 23 (296) W Oct 24 (297) T Oct 25 (298) 12th STEREO launch anniversary F Oct 26 (299) S Oct 27 (300) S Oct 28 (301) ------------------------------------------------------------------------------- Scheduled activities for Week 44: M Oct 29 (302) T Oct 30 (303) W Oct 31 (304) T Nov 1 (305) F Nov 2 (306) S Nov 3 (307) S Nov 4 (308) ------------------------------------------------------------------------------- Scheduled activities for Week 45: M Nov 5 (309) T Nov 6 (310) W Nov 7 (311) T Nov 8 (312) F Nov 9 (313) S Nov 10 (314) S Nov 11 (315) ------------------------------------------------------------------------------- Upcoming events: Behind events are contingent on recovering the spacecraft. 2018: * Nov 4,5,6 Ahead: SECCHI COR2 deep exposure campaign with first Parker Solar Probe perihelion (dates TBC) 2019: * Mar Ahead: Switch downlink rate to 240 kbps for 34 meter * Apr Behind: Switch downlink rate to 240 kbps for 34 meter * Nov 4 Ahead: Close approach of Parker Solar Probe 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 2022: 2023: * May 5 Behind: Mercury transit * Jul 17 Behind: Closest approach to Earth * Aug 13 Ahead: Closest approach to Earth 2024: 2025: * Apr 7 Ahead: Mercury transit 2026: 2027: * Feb 1 Behind: Mercury transit 2028: 2029: * Jun 30 Ahead: Mercury transit