STEREO Weekly Meeting Minutes for 2015-08-18 (Week 34) ANNOUNCEMENTS ------------- * None. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * Ahead is now operating on the first side lobe. * There are currently no communications with the Behind spacecraft. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 33 (Aug 10-16) * On day 223 (Aug 11), during the DSS-55 support for Ahead, the DCD1 failed over to the backup DCD2. All telemetry data were recovered. See DR# M108946 for more information. * On day 225 (Aug 13), initial acquisition of telemetry for the DSS-43 support for Ahead occurred 13 minutes late at 2358z due to a downlink receiver issue. A second receiver was added which locked to the downlink signal. This anomaly resulted in the loss of 13 minutes of real-time data and spacecraft SSR playback data. See DR# C111318 for more information. * On day 227 (Aug 15), initial acquisition of telemetry for the DSS-35 support for Ahead occurred 55 minutes late at 0345z as the station was declared red due to mechanical pointing issue. The antenna was re-calibrated which cleared the anomaly. This anomaly resulted in the loss of 55 minutes of telemetry, tracking, and commanding support. See DR# C111321 for more information. * The Ahead observatory operated nominally during this week on the 2nd side lobe of the HGA to prevent overheating of the HGA feed assembly which was at 107 degrees C and decreasing with the HGA angle at 9.6 degrees and increasing, with respect to the spacecraft-Sun line. * On day 228 (Aug 16), at the end of the DSS-14 support for Ahead, the HGA was positioned to return to the 1st HGA side lobe for communications at 1953z to increase data rates while preventing overheating of the HGA feed assembly. This increased the HGA feed assembly temperature to 121.9 degrees C, which is within the predicted range, with the HGA angle at 6.8 degrees, with respect to the spacecraft-Sun line. For the 1st side lobe, data rates for the daily 70 meter supports are 10 kbps on the downlink and 500 bps on the uplink. Data rates for the 34 meter supports remain unchanged at 633 bps down and 125 bps up. The MOC is looking into the possibility of increasing the downlink speed on the 34 meter stations to 3 kbps. * The average daily science data return for Ahead, while operating on the 2nd side lobe on the HGA, was 54 Mbits during this week. * The SECCHI team commented that they didn't see some expected event messages on Saturday. The MOC responded that this was due to the late acquisition on station 35 on that day. * Solar scintillation effects have greatly declined. The Ahead SPE angle is currently 3.5 degrees, which just about clears the scintillation region. Also, the Sun has been very quiet. * Behind is currently at an SPE angle of 2.5 degrees and declining. Attempts to recover Behind will resume in December. The uplink margin on the LGA will return to 6 dB in March 2016, and the downlink margin will return to 3 dB in December 2016, which should improve the chances of recovering the spacecraft. Week 34 (Aug 17-23) * Ahead starts the week at an SPE angle of 3.6 degrees, on the first side lobe. Alternating weeks of IMPACT-prime and SWAVES-prime will resume, starting with IMPACT being prime. * G&C parameter set 1.3.3 will be loaded to RAM on Ahead tomorrow (Aug 19) to increase the propulsion system enable delay. This change is in preparation to the switch to no gyro operations later this year. * Ahead has 14 passes during the week, with seven passes at 10 kbps, and 7 passes at 633 bps, with overall space weather coverage of 31%. * Behind starts the week at an SPE angle of 2.4 degrees. There will be no passes for Behind during the week. Week 35 (Aug 24-30) * Ahead starts the week at an SPE angle of 3.9 degrees, on the first side lobe, with SWAVES being prime. * The 79th momentum dump on Ahead will be carried out Monday, Aug 24, with ignition at 18:00 UT. This momentum dump will be performed with IMU-2 on. The MOC is tightening up the parameters for this maneuver. * The IMPACT SIT calibration tables will be uploaded on Wednesday, Aug 26, during the station 14 support. This is about a four hour pass, with an increased uplink speed (compared to the second side lobe) of 500 bps. * Ahead has 19 passes during the week, with seven passes at 10 kbps, and twelve passes at 633 bps, with overall space weather coverage of 41%. * Behind starts the week at an SPE angle of 2.2 degrees. There will be no passes for Behind during the week. Week 36 (Aug 31-Sep 6) * Ahead starts the week at an SPE angle of 4.1 degrees, on the first side lobe, with IMPACT being prime. * G&C parameter set 1.3.3 will be written to EEPROM on Ahead on Monday, Aug 31. * The MOC will resume using ESA stations with Ahead, to increase the amount of space weather coverage. The first pass will be a 7 hour Cebreros support on Sep 1. A total of 100 hours of ESA support is allocated. * Ahead has 18 passes during the week, with eight passes at 10 kbps, and ten passes at 633 bps, with overall space weather coverage of 35%. * Behind starts the week at an SPE angle of 2.1 degrees. There will be no passes for Behind during the week. Week 37 (Sep 7-13) * APL will be closed on Monday, Sep 7, for the Labor Day holiday. * Ahead starts the week at an SPE angle of 4.3 degrees, on the first side lobe, with SWAVES being prime. * Ahead has 15 passes during the week, with seven passes at 10 kbps, and eight passes at 633 bps, with overall space weather coverage of 31%. An ESA pass is scheduled for Tuesday, Sep 8. * Behind starts the week at an SPE angle of 2.0 degrees. There will be no passes for Behind during the week. Week 38 (Sep 14-20) * Ahead starts the week at an SPE angle of 4.5 degrees, on the first side lobe, with IMPACT being prime. * Ahead has 16 passes during the week, with eight passes at 10 kbps, and eight passes at 633 bps, with overall space weather coverage of 31%. * Behind starts the week at an SPE angle of 1.9 degrees. There will be no passes for Behind during the week. Week 39 (Sep 21-27) * Ahead starts the week at an SPE angle of 4.8 degrees, on the first side lobe, with SWAVES being prime. * Ahead has 13 passes during the week, with eight passes at 10 kbps, and five passes at 633 bps, with overall space weather coverage of 23%. * Behind starts the week at an SPE angle of 1.9 degrees. There will be no passes for Behind during the week. After this week, the SPE angle will start to rise back up again. Week 40 (Sep 28-Oct 4) * Ahead starts the week at an SPE angle of 5.0 degrees, on the first side lobe, with IMPACT being prime. * Oct 1 marks the beginning for STEREO of the third extended mission. * 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 31%. Other * There's been a problem over the last couple of weeks ingesting SECCHI data from NRL to the SSC due to changed network security rules. This problem is being actively worked on. In the meantime, much of the data has been copied over by hand for ingestion into the SSC. * SECCHI expressed interest in keeping track of what attitude history data has been downloaded from the SSR. These data are currently delayed because of the need to bring down the anomaly data during superior solar conjunction. The MOC will include this information in the weekly status reports. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 34: M Aug 17 (229) T Aug 18 (230) W Aug 19 (231) T Aug 20 (232) F Aug 21 (233) S Aug 22 (234) S Aug 23 (235) 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 35: M Aug 24 (236) Ahead: Momentum dump, 18:00 UT T Aug 25 (237) W Aug 26 (238) Ahead: IMPACT SIT calibration table upload T Aug 27 (239) F Aug 28 (240) S Aug 29 (241) S Aug 30 (242) 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 36: M Aug 31 (243) T Sep 01 (244) W Sep 02 (245) T Sep 03 (246) F Sep 04 (247) S Sep 05 (248) S Sep 06 (249) 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 37: M Sep 07 (250) Labor Day T Sep 08 (251) W Sep 09 (252) T Sep 10 (253) F Sep 11 (254) S Sep 12 (255) S Sep 13 (256) 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 38: M Sep 14 (257) T Sep 15 (258) W Sep 16 (259) T Sep 17 (260) F Sep 18 (261) S Sep 19 (262) S Sep 20 (263) 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 39: M Sep 21 (264) T Sep 22 (265) W Sep 23 (266) T Sep 24 (267) F Sep 25 (268) S Sep 26 (269) S Sep 27 (270) 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 40: M Sep 28 (271) T Sep 29 (272) W Sep 30 (273) T Oct 01 (274) Begining of 3rd extended STEREO mission. F Oct 02 (275) S Oct 03 (276) S Oct 04 (277) Notes: * Ahead operating on the first side lobe, in IMPACT-prime mode. * No tracks for Behind due to superior solar conjunction. ------------------------------------------------------------------------------- Upcoming events: Behind events are contingent on recovering the spacecraft. 2015: * Nov 10 Ahead: HGA on main lobe, offpoint 1 degree, 240 kbps Ahead: SSR playback and reconfiguration, S/C checkout Ahead: Resume space weather broadcast to NOAA stations * Nov 12 Ahead: Instrument recommissioning * Nov 16 Ahead: HGA on main lobe, offpoint 1 degree, 360 kbps Behind: Resume Behind recovery efforts * Nov 20 Behind: HGA on 1st side lobe * Nov 30 Ahead: HGA on main lobe, offpoint 1 degree, 480 kbps * Dec 30 Ahead: HGA on main lobe 2016: * Jan 2 Behind: HGA on main lobe, offpoint 1 degree Behind: SSR playback and reconfiguration, S/C checkout * Jan 5 Behind: Instrument recommissioning * Jan 12 Behind: HGA on main lobe * Jan 27 Both: HGA calibration * 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 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