STEREO Weekly Meeting Minutes for 2015-09-08 (Week 37) ANNOUNCEMENTS ------------- * None. 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 36 (Aug 31-Sep 6) * On day 244 (Sep 1), before the beginning of the 1st Ahead support with DSS-34 that day, the transmitter was declared red and the support remained downlink only for the duration. This anomaly resulted in the loss of 5.3 hours of commanding and two-way Doppler support. See DR# C111354 for more information. * On day 244 (Sep 1), before the beginning of the 2nd Ahead support with DSS-34 that day, the transmitter was declared red and the support remained downlink only for the duration. This anomaly resulted in the loss of 3.2 hours of commanding and two-way Doppler support. See DR# C111356 for more information. The station 34 transmitter is now back to operating status. * On day 248 (Sep 5), during the DSS-65 support for Ahead, turbo decoder lock was lost intermittently between 1441z and 1545z. This anomaly resulted in the loss of 30 frames of real-time data. * On day 249, during the DSS-14 support, turbo decoder lock was lost briefly at 1954z. This anomaly resulted in the loss of 3 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 117 degrees C and decreasing with the HGA angle at 7.5 degrees and increasing, with respect to the spacecraft-Sun line. * On day 243 (Aug 31), G&C parameters release 1.3.3 was loaded to G&C EEPROM. This release increased the propulsion subsystem enable delay for G&C thruster use to 60 seconds in preparation for No Gyro Operations (NGO) to be deployed later this year. * This week, data for the following days was played back from the C&DH routine SSR partition playback: 2015-240-11:47:25z through 2015-249-22:29:08z 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 93 Mbits during this week. * Planning continues for resuming recovery operations of the Behind spacecraft in December. There will be a test on Ahead of the frequency sequence acquisition mode with Ahead on Sep 29. Testing of the uplink array capability is also expected to resume sometime this fall--there will be telecon with DSN on this issue tomorrow (Sep 9). As Behind approaches Earth again, the LGA margins will get better. The uplink margin will return to 6 dB in Mar 2016, and the downlink margin will return to 3 dB in Dec 2016. 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. * 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 occurred this morning, Sep 8. Telemetry bind was 20 minutes late due to a ground delivery issue, but all data were recovered. * 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. * The station 35 pass for Ahead on Tuesday, Sep 22, will be a project interface test of the new uplink software with ranging. Real-time telemetry will flow during this test, but there will be no instrument commanding. There is a track two hours later that can be used for commanding. * 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. 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. * The station 43 pass for Ahead on Tuesday, Sep 29, will be used to test the frequency acquisition mode developed for recovering the Behind spacecraft. Two DSN receivers will be used during this pass, one in coherent mode and the other in non-coherent mode, so the science data should not be impacted. However, there will be no instrument commanding during this pass. The spacecraft will stay on the HGA, so the downlink rate will remain at 10 kbps, but the uplink rate will be changed to 7.8 bps. * The 80th momentum dump on Ahead will be performed on Wednesday, Sep 30, with ignition at 22:30 UT. The IMU will be turned on during the momentum dump. * 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%. * Behind starts the week at an SPE angle of 1.9 degrees. There will be no passes for Behind during the week. Week 41 (Oct 5-11) * Ahead starts the week at an SPE angle of 5.2 degrees, on the first side lobe, with SWAVES being prime. * 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 26%. * Behind starts the week at an SPE angle of 2.0 degrees. There will be no passes for Behind during the week. 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%. * 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. * 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. Other * DSN wished to know whether an uplink array test with Ahead in the DSN forecast schedule for week 50 will be kept. There are also currently two simultaneous supports in week 44 which could be used for an uplink array test. This will be decided during the telecon with the DSN tomorrow (Sep 9). * The MOC is preparing plans for coming out of side-lobe operations mode, and will send out these plans for comment soon. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- 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) Ahead: Project interface test with station 35 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) Ahead: Test of frequence acquisition mode with station 43 W Sep 30 (273) Ahead: Momentum dump, 22:30 UT 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. ------------------------------------------------------------------------------- Scheduled activities for Week 41: M Oct 05 (278) T Oct 06 (279) W Oct 07 (280) T Oct 08 (281) F Oct 09 (282) S Oct 10 (283) S Oct 11 (284) 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 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. ------------------------------------------------------------------------------- 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