STEREO Weekly Meeting Minutes for 2015-08-11 (Week 33) ANNOUNCEMENTS ------------- * None. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * Ahead is back to normal operations on the second side lobe. * There are currently no communications with the Behind spacecraft. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 32 (Aug 3-9) * On day 215 (Aug 3), during the DSS-34 support for Ahead, turbo decoder lock was lost intermittently for the 3.4 hour duration of the track due to the effects of solar scintillation. A second downlink receiver was added which displayed the same performance. This anomaly resulted in the loss of 607 frames (70% of expected telemetry) of real-time data. See DR# C111289 for more information. * On day 215 (Aug 3), during the DSS-14 support for Ahead, turbo decoder lock was lost briefly at 1456z due to the effects of solar scintillation. This anomaly resulted in the loss of one frame of real-time data. * On day 216 (Aug 4), during the DSS-34 support for Ahead, turbo decoder lock was lost intermittently between 0254z through 0555z due to the effects of solar scintillation. At 0349z the command uplink was lost when the transmitter tripped off-line due to a loss of 480V power at the station. The support remained downlink only for the duration. This anomaly resulted in the loss of 24 frames of real-time data. See DR# C111293 for more information. * On day 216 (Aug 4), during the DSS-65 support for Ahead, turbo decoder lock was lost intermittently between 0745z through 1322z due to the effects of solar scintillation. This anomaly resulted in the loss of 14 frames of real-time data. * On day 216 (Aug 4), during the DSS-14 support for Ahead, turbo decoder lock was lost intermittently between 1527z through 1538z due to the effects of solar scintillation. This anomaly resulted in the loss of 4 frames of real-time data and spacecraft SSR playback data. * On day 217 (Aug 5), during the DSS-14 support for Ahead, turbo decoder lock was lost briefly at 1508z due to the effects of solar scintillation. This anomaly resulted in the loss of 2 frames of real-time data. * On day 218 (Aug 6), during the DSS-25 support for Ahead, the SSR playback timetags were deleted for the next support with DSS-43 as the MOC was notified that DSS-43 was declared red. * On day 218 (Aug 6), during the DSS-43 support for Ahead, the antenna was returned to operational status and telemetry was received at 219-0017z. The spacecraft SSR playback was started at 0100z. This anomaly resulted in the loss of 107 minutes of telemetry, tracking, and commanding support. See DR# C111303 for more information. * On day 219 (Aug 7), during the DSS-43 support for Ahead, turbo decoder lock was lost intermittently between 220-0211z through 0227z due to the effects of solar scintillation. This anomaly resulted in the loss of 232 frames of real-time data and spacecraft SSR playback data. * On day 220 (Aug 8), initial acquisition of telemetry for the DSS-54 support for Ahead occurred at 1300z due to a complex wide power outage. This anomaly resulted in the loss of 5 hours of telemetry, tracking, and commanding support. See DR# M108930 for more information. * The Ahead observatory is operating nominally on the 2nd side lobe of the HGA to prevent overheating of the HGA feed assembly which is currently at 108 degrees C and decreasing with the HGA angle at 9.4 degrees and increasing, with respect to the spacecraft-Sun line. * The average daily science data return for Ahead, while operating on the 2nd side lobe on the HGA, was 44 Mbits during this week. Week 33 (Aug 10-16) * A project interface test (PIT) using station 35 was carried out with Ahead yesterday (Aug 10) to test new uplink software. The results were nominal. * There is a 1.7 hour return-to-service track for station 63 tomorrow (Aug 12). There will be no commanding or SSR playback during this track. * Ahead will shift to the 1st side lobe near the end of the third 70 meter track (station 14) on Sunday, Aug 16. There will be a 34 meter support following this shift using station 35, though still at 633 bps. This 7.25 hour support will allow the MOC to monitor the HGA temperature. The first 10 kbps support will be on Monday, Aug 17. * Ahead has 17 tracks during the week, nine using 70 meter stations at 3 kbps, and eight using 34 meter stations at 633 bps, giving an overall space weather coverage of 55%. * Ahead starts the week at an SPE angle of 3.3 degrees, on the second side lobe. This will be the last week on the second side lobe. * Behind starts the week at an SPE angle of 2.5 degrees. There will be no passes for Behind during the week. 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. * 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. * 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. * 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) * Ahead starts the week at an SPE angle of 4.3 degrees, on the first side lobe, with SWAVES being prime. * APL will be closed on Monday, Sep 7, for the Labor Day holiday. * Ahead has 14 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 15 passes during the week, with eight passes at 10 kbps, and seven passes at 633 bps, with overall space weather coverage of 26%. 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. Other * The MOC will coordinate with the IMPACT team to schedule a time to upload the SIT calibration tables. Once the spacecraft is on the first side lobe, the uplink rate will increase, and should be more reliable. * The MOC is looking for an opportunity to schedule a test on Ahead of the frequency segmentation scheme being used to try to recover Behind. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 33: M Aug 10 (222) Ahead: Project interface test with station 35 T Aug 11 (223) W Aug 12 (224) Ahead: Return-to-service track with station 63 T Aug 13 (225) F Aug 14 (226) S Aug 15 (227) S Aug 16 (228) Ahead: Switch to first side lobe. Notes: * Ahead operating on second side lobe. * No tracks for Behind due to superior solar conjunction. ------------------------------------------------------------------------------- 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) 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. ------------------------------------------------------------------------------- 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