STEREO Weekly Meeting Minutes for 2012-09-04 (Week 36) ANNOUNCEMENTS ------------- * None INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 35 (Aug 27 - Sep 2) * On day 241 (Aug 28), during the DSS-14 support for Ahead, the uplink was established late at 1435z due to a transmitter anomaly at the station. Later in the support, at 1610z, the transmitter modulation was lost for several seconds. SSR pointers were repositioned to minimize data loss. These anomalies resulted in the loss of 140 minutes of commanding and tracking data. All SSR data were received. See DRs# G113170, G113171, and G113172 for more information. * On day 242 (Aug 29), the RAID array for the main file server in the STEREO MOC had a disk anomaly at 1430z. This impacted planning, assessment, and data product generation in the MOC for both spacecraft. Real-time control operations were not affected. On day 243 (Aug 30) at 2300z, after repartitioning one disk, the main file server was back on-line. The anomaly resulted in the delay of data products for days 242 and 243. * On day 242 (Aug 29), during the DSS-14 support for Ahead, the downlink carrier lock was lost for eight seconds. Carrier lock was reestablished without manual intervention at the station. This anomaly resulted in the loss of several minutes of SSR data for each instrument. See DR# G113176 for more information. * On day 243 (Aug 30), during the DSS-34 support for Ahead, turbo decoder lock was lost briefly at 2324z. The anomaly resulted in the loss of four frames of SSR data. See DR# N108353 for more information. * On day 244 (Aug 31), during the DSS-15 support for Ahead, turbo decoder lock was lost briefly at 1419z and again 1510z. The anomaly resulted in the loss of two frames of SSR data. See DR# N108354 for more information. * On day 246 (Sep 2), during the DSS-14 support for Ahead, turbo decoder lock was lost briefly at 1611z. The anomaly resulted in the loss of 190 frames of SSR data. A DR has been requested. * On day 240 (Aug 27), during the DSS-24 support for Behind, the uplink was lost when the transmitter went unmodulated at 205719z. The command bind was lost, which interfered with SCMs that were being transmitted by SECCHI at that time. The transmitter went modulated at 205721 and bind was restored shortly thereafter. The affected SCMs were then retransmitted. See DR #G113168 for more information. The uplink was not reswept, and no SSR data were lost. * On day 242 (Aug 29), during the DSS-25 support for Behind, turbo decoder lock was lost intermittently beginning at 2324z through 2430003z. This anomaly resulted in the loss of 77 frames of SSR data. See DR# N108342 for more information. * On day 243 (Aug 30), during the DSS-65 support for Behind, turbo decoder lock was lost intermittently beginning at 1639z through 1838z. This anomaly resulted in the loss of eight frames of SSR data. See DR# N108351 for more information. * On day 244 (Aug 31), during the DSS-54 support for Behind, turbo decoder lock was lost briefly at 1810z. This anomaly resulted in the loss of one frame of SSR data. See DR# N108352 for more information. * On day 246 (Sep 2), during the DSS-25 support for Behind, turbo decoder lock was lost briefly at 0147z. This anomaly resulted in the loss of one frame of SSR data. A DR has been requested. * The average daily SSR playback volume during the week was 5.1 gigabits for Ahead, and 4.5 gigabits for Behind. Week 36 (Sep 3-9) * Frames were lost during the station 65 passes yesterday (Sep 3) for both spacecraft. * There was a SECCHI watchdog reset yesterday (Sep 3) on Behind, between 13-15:16 UT. * The 22nd SECCHI stepped calibration roll on Behind was carried out today (Sep 4), starting at 11:15 UT. This was the midpoint roll. Midpoint was actually the week before. * The start of the station 65 pass for Behind today (Sep 4) was delayed by 30 minutes. * A DSN parameter was changed today (Sep 4) for both spacecraft, to open the carrier loop bandwidth to 100 Hz in an effort to help mitigate the turbo decoder lock issues. Two causes of dropping decoder lock have been been identified, one is a turbo decoder glitch, and the other is a potential RFI issue. Opening up the carrier loop bandwidth is intended to address the latter. This change was originally reported as being intended to investigate the former. * Ahead has 70 meter passes on Friday, Sep 7 (D14), Saturday, Sep 8 (D14 at 720 kbps), and Sunday, Sep 9 (D63). There are 12 passes during the week, and overall coverage is nominal. * Behind has 70 meter passes on Monday, Sep 3 (D14), Friday, Sep 7 (D63), and Saturday, Sep 8 (D63). There are 12 passes during the week, and overall coverage is nominal. The station 65 pass on Monday, Sep 3, and the station 54 pass on Sunday, Sep 9, will both be carried out at 240 kbps. An ESA New Norcia pass is scheduled for Thursday, Sep 6. Week 37 (Sep 10-16) * Ahead has 70 meter passes on Monday, Sep 10 (D63), Tuesday, Sep 11 (D63), Wednesday, Sep 12 (D14), Saturday, Sep 15 (D14), and Sunday, Sep 16 (D63). There are 10 passes during the week, and overall coverage is nominal. * Behind has 70 meters every day between Tuesday through Sunday, Sep 11-16. There are 9 passes during the week, and overall coverage is nominal. An ESA New Norcia pass is scheduled for Tuesday, Sep 11. Week 38 (Sep 17-23) * The 23rd SECCHI stepped calibration roll on Ahead will be carried out on Tuesday, Sep 18, starting at 08:40 UT. System momentum will be about 4 N-m-s. This is the aphelion roll--aphelion is actually the following week. * The Hubble space telescope will be making special observations of the planet Jupiter on Sep 20 to observe the dimming caused by a transit of Venus across the face of the Sun as seen from Jupiter. These observations will test the ability to extract information about Venus's atmosphere by observing the dimming in multiple bandpasses, and will serve to test how this procedure can be used to explore the atmospheres of exoplanets. Simultaneous observations of the Sun from SDO and STEREO Ahead are desired to monitor possible solar activity which could affect the measurements. * Ahead has 70 meter passes every day of the week, with two on Monday, Sep 17, two on Tuesday, Sep 18, and two on Sunday, Sep 23. There are 14 passes during the week, and overall coverage is nominal. * Behind has 70 meter passes on Monday, Sep 17 (D63), Wednesday, Sep 19 (D14), Thursday, Sep 20 (D14), and Friday, Sep 21 (D63). There are 12 passes during the week, and overall coverage is nominal. The station 45 passes on Wednesday, Sep 19, and Friday, Sep 21, will be carried out at 240 kbps. ESA New Norcia passes are scheduled for Tuesday, Sep 18, and Sunday, Sep 23. Week 39 (Sep 24-30) * Ahead reaches aphelion on Sep 26. * Sep 30 marks the end of the 2nd extended mission for STEREO. * Momentum dumps are scheduled for both spacecraft during the week, with the 50th dump on Ahead scheduled for Sep 24 at 16:00 UT, and the 45th dump on Behind scheduled for Sep 25 at 15:00 UT. These dumps were scheduled a week early due to track coverage. * The second battery discharge cycling on Ahead is scheduled for the morning of Sep 26, starting at 14:00 UT. This will be for 2 hours during a station 14 track. * Project Interface Tests (PIT) will be carried out with the Ahead spacecraft on Thursday, Sep 27 for 1.8 hours using station 24, and Sunday, Sep 30 for 3.2 hours using station 26. Realtime data will be flowing during these tests, but there will be no instrument commanding or SSR playback. * Ahead has 70 meter passes every day except Thursday, Sep 27, with two passes on Tuesday, Sep 25, and Sunday, Sep 30. The first 70 meter pass on each of those two days, using station 63, will be at 720 kbps. There are 11 passes during the week, and overall coverage is nominal. * Behind has 70 meter passes on Monday, Sep 24 (D14), Tuesday, Sep 25 (D63 at 720 kbps), Thursday, Sep 27 (D14, D63), and Friday, Sep 28 (D14). There are 9 passes during the week, and overall coverage is nominal. An ESA New Norcia pass is scheduled for Friday, Sep 28. Week 40 (Oct 1-7) * Testing of the turbo encoding mode for the space weather beacon data will be carried out with Ahead on Wednesday, Oct 3, starting at 10:05 UT after the station 63 pass, and with Behind on Thurday, Oct 4, starting at 11:50 UT after the ESA New Norcia pass. * Ahead has 70 meter passes on Monday, Oct 1 (D14), Wednesday, Oct 3 (D63), Saturday, Oct 6 (D63), and Sunday, Oct 7 (D63). There are 11 passes during the week, and overall coverage is nominal. * Behind has 70 meter passes on Monday, Oct 1 (D14 at 720 kbps), Friday, Oct 5 (D43, D14), and Saturday, Oct 6 (D14 at 720 kbps). There are 9 passes during the week, and overall coverage is nominal. An ESA New Norcia pass is scheduled for Thursday, Oct 4. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 36: M Sep 03 (247) Labor Day Behind: SECCHI watchdog reset, 13:-15:6 UT T Sep 04 (248) Behind: SECCHI stepped calibration roll, 11:15 UT W Sep 05 (249) T Sep 06 (250) F Sep 07 (251) S Sep 08 (252) S Sep 09 (253) ------------------------------------------------------------------------------- Scheduled activities for Week 37: M Sep 10 (254) T Sep 11 (255) W Sep 12 (256) T Sep 13 (257) F Sep 14 (258) S Sep 15 (259) S Sep 16 (260) ------------------------------------------------------------------------------- Scheduled activities for Week 38: M Sep 17 (261) T Sep 18 (262) Ahead: SECCHI stepped calibration roll, 08:40 UT W Sep 19 (263) T Sep 20 (264) Ahead: Venus transit as seen from Jupiter F Sep 21 (265) S Sep 22 (266) S Sep 23 (267) ------------------------------------------------------------------------------- Scheduled activities for Week 39: M Sep 24 (268) Ahead: Momentum dump, 16:00 UT T Sep 25 (269) Behind: Momentum dump, 15:00 UT W Sep 26 (270) T Sep 27 (271) F Sep 28 (272) S Sep 29 (273) S Sep 30 (274) ------------------------------------------------------------------------------- Scheduled activities for Week 40: M Oct 01 (275) T Oct 02 (276) W Oct 03 (277) Ahead: Turbo beacon test, 10:05-04:55 next day T Oct 04 (278) Behind: Turbo beacon test, 11:50-17:40 F Oct 05 (279) S Oct 06 (280) S Oct 07 (281) Notes: * Tests of Turbo decoding of beacon data from European stations on both spacecraft. ------------------------------------------------------------------------------- Upcoming events: 2012: * Nov 4 Behind: Switch downlink rate to 120 kbps * Nov 13 Total solar eclipse, south Pacific 2013: * May 3 Ahead: Switch downlink rate to 120 kbps * Dec 12 Ahead: Mercury transit 2014: * Jan 20 Behind: End use of 480 kbps on 70 m DSN subnet * Apr 21 Behind: Resume use of 480 kbps on 70 m DSN subnet * Apr 29 Behind: Mercury transit * Oct 15 Behind: End use of 480 kbps on 70 m DSN subnet 2015: * Feb DAWN - Ceres arrival * Jan 20 - Mar 28 (TBC) Behind: Spacecraft behind Sun * Mar 17 - Jul 14 (TBC) Ahead: Spacecraft behind Sun * Jul 2 Behind: Resume use of 480 kbps on 70 m DSN subnet * Aug 25 - Oct 19 (TBC) Behind: Spacecraft behind Sun * Sep 25 Behind: End use of 480 kbps on 70 m DSN subnet * Jul DAWN - End of nominal mission 2016: * Apr 3 Behind: Resume use of 480 kbps on 70 m DSN subnet 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