STEREO Weekly Meeting Minutes for 2015-09-15 (Week 38) 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 37 (Sep 7-13) * On day 251 (Sep 8), during the DSS-83 support for Ahead, real-time receipt of telemetry occurred 20 minutes late at 1110z due to a SLE telemetry bind issue. All real-time data were recovered post track. See DR# N110042 for more information. * On day 254 (Sep 11), during the DSS-63 support, ranging data was lost beginning at 1240z due to a RRT processor issue. This anomaly resulted in the loss of 147 minutes of ranging data. See DR# M108993 for more information. * On day 255, during the DSS-54 support, turbo decoder lock was lost briefly at 1042z. This anomaly resulted in the loss of 1 frame of real-time data. Also, although uplink carrier lock was achieved, the command detector never locked during the support. This anomaly resulted in no commands being received by the spacecraft. It was later determined that this was due to a DSN misconfiguration of the uplink rate. * 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 116 degrees C and decreasing with the HGA angle at 7.7 degrees and increasing, with respect to the spacecraft-Sun line. * This week, data for the following days was played back from the C&DH routine SSR partition playback: 2015-249-22:29:08z through 2015-256-00:23:21z 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 84 Mbits during this week. * There are currently no operations for Behind due to a small separation angle with the Sun. Attempts to recover the spacecraft will resume Nov 30. A test of the frequency acquisition mode for recovering Behind will be tested on Ahead on Sep 29. On Oct 8 there will be an uplink array test with Ahead using stations 24 & 25, and there will be additional uplink array tests at the rate of about one test per month. Once the uplink array capability is operational, it will be used on Behind, possibly starting sometime in early 2016. The uplink margin on Behind with the LGA will return to 6 dB in March 2016, and the downlink margin will return to 3 dB in December 2016. 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. The DSN commented that they may not need this pass as a PIT test after all, so it may be reconverted back to a normal pass. * 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 14 passes during the week, with eight passes at 10 kbps, and five passes at 633 bps, with overall space weather coverage of 32%. * 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. * Uplink array testing will resume on Thursday, Oct 8, with stations 24 & 25. This test will include commanding. The uplink rate will be 7.8 bps. The rate of certain HK APIDs will be increased to return more transponder data. The test duration is 5.9 hours. Tests will continue at about once per month, using different configurations. * 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. 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. * 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. Other * The MOC went over a presentation that had been mailed out to the instrument teams. The spacecraft will return to the main lobe of the HGA with a one degree offset on Nov 10, and will start to play back the recorder. The NOAA stations will also be able to resume capturing space weather telemetry between DSN passes. The nominal 70 meter telemetry will start out at 240 kbps, and will gradually increase as the HGA rides along its soft stop and approaches the center of the main lobe. * There is some additional recorder space for IMPACT, PLASTIC, and SWAVES which can be used for storing additional data before the recorder is read out. This works out to about one packet per minute each for IMPACT and PLASTIC, and about two packets per minute for SWAVES. (IMPACT would need to wait until next week before starting.) The instrument teams expressed interest in using this space. They need to work with the MOC to open up additional APIDs to the recorder. * Real-time telemetry rates will remain at the first side lobe rates until the SSR is reconfigured on Nov 16. This will allow real-time data from the instruments to continue while the recorder is read out. The space weather beacon stream during this period will continue to include some spacecraft housekeeping data. All the support during this period is expected to be on 70 meter stations at high elevation, so the telemetry rate will be boosted to 360 kbps. The last day at side lobe 1 rates will be Sunday, Nov 15. * SECCHI is requested to limit their telemetry between 10:00 and 10:20 UT on Monday, Nov 16, to avoid jamming queues during the SSR reconfiguration. * Once the SSR is reconfigured, all the instruments can return to the configuration they were in just before the start of side-lobe operations. The MOC suggests that this change be made after the end of the track, or on the following day. The space weather beacon telemetry will no longer contain space weather housekeeping data. * On Tuesday, Nov 17, SWEA and STE on IMPACT will be powered on, and the SWEA high voltages will start to be ramped up. The DSN schedule on Tuesday and Wednesday is rather thin, but gets better later in the week. * An uplink array test using stations 25 and 26 is scheduled for Thursday, Nov 19. There will be no instrument commanding during this test. * No Gyro Operations (NGO) will begin in December. The MOC wishes to limit not only the number of hours that the IMU is used, but also the number of times that it's power cycled. The first NGO momentum dump will be on Dec 2, the first SECCHI stepped calibration roll on Jan 12, and the first HGA calibration on Jan 27. The calibration rolls and HGA calibrations are expected to take longer than before. Accelerometer data will not be available during the momentum dump, but this doesn't actually change much between dumps. SECCHI expressed some interest in having an earlier calibration roll, perhaps using the IMU--this is being looked at. * Once the recorder is read out, it may take the MOC 2-3 months to process the data into level-0 files and attitude history files. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- 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) Ahead: Uplink array test with stations 24 & 25. 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. ------------------------------------------------------------------------------- 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. ------------------------------------------------------------------------------- Upcoming events: Behind events are contingent on recovering the spacecraft. 2015: * Nov 10 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 * Nov 15 Ahead: Resume prime science real-time telemetry rates * Nov 16 Ahead: SSR playback and reconfiguration Ahead: No SECCHI telemetry 10:00-10:20 UT Ahead: End S/C telemetry in space weather broadcast * Nov 17 Ahead: Instrument recommissioning, IMPACT SWEA/STE on * Nov 19 Ahead: HGA on main lobe, riding soft stop, 360 kbps Ahead: Uplink array test (DSS-25 & 26) * Nov 20 Behind: HGA on 1st side lobe * Nov 23 Ahead: 96 kbps on 34 meter stations * 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