STEREO Weekly Meeting Minutes for 2012-09-18 (Week 38) ANNOUNCEMENTS ------------- * None INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 37 (Sep 10-16) * On day 254 (Sep 10), during the DSS-63 support for Ahead, turbo decoder lock was lost briefly at 0619z. This anomaly resulted in the loss of five frames of SSR data. See DR# N108396 for more information. * On day 256 (Sep 12), during the DSS-14 support for Ahead, turbo decoder lock was lost briefly at 1231z due to an antenna elevation track error. SSR pointers were repositioned to minimize data loss. All SSR data were recovered. See DR# G113212 for more information. * On day 257 (Sep 13), during the DSS-55 support for Ahead, turbo decoder lock was lost briefly at 0643z. This anomaly resulted in the loss of three frames of SSR data. See DR# N108409 for more information. * On day 258 (Sep 14), during the DSS-25 support for Ahead, the entire track was missed due to a power failure at the Goldstone complex (caused by voltage sag from the external power service provider). Due to the amount of lost track time, only the PLASTIC instrument SSR pointers were repositioned on the next track to minimize data loss. These anomalies resulted in the loss of eleven hours of day 257 SSR data for IMPACT, SECCHI, and SWAVES. See DR# G113219 for more information. There was some discussion about when the station switches over to generator power. The State of California only allows the use of generator power at the station in emergency situations. There are guidelines as to when they're allowed to switch to generator power. * On day 259 (Sep 15), the SWAVES science partition on Ahead reached 100% full at 0156z for 3.8 hours. * On day 259 (Sep 15), during the DSS-14 support for Ahead, turbo decoder lock was lost briefly at 1523z. This anomaly resulted in the loss of seven frames of real-time VC7 data. See DR# N108416 for more information. * On day 260 (Sep 16), during the DSS-63 support for Ahead, turbo decoder lock was lost intermittently beginning at 0737z through 0819z. This anomaly resulted in the loss of six frames of SSR data. See DR# N108414 for more information. * On day 255 (Sep 11) during the DSS-32 (New Norcia) support for Behind, turbo decoder lock was lost intermittently beginning at 1128z through 1131z. MOPS performed an SLE telemetry offline transfer of DSS-32 equipment chain two data and recovered 40 frames of lost SSR data. This anomaly resulted in the loss of seven frames of SSR data. This anomaly is being investigated with ESA. * On day 256 (Sep 12), during the DSS-63 support for Behind, turbo decoder lock was lost intermittently beginning at 1535z through 1758z. Also during the support, JPL COMM switched to the MDSCC Back-Up NTR circuit at 1717z, which caused monitor data to stop flowing until JPL switched back to the MDSCC Prime NTR circuit at 1731z. The turbo decoder anomaly resulted in the loss of 213 frames of SSR data. See DRs# N108408 and N108403 for more information. * On day 257 (Sep 13), during the DSS-63 support for Behind, turbo decoder lock was lost intermittently beginning at 1531z through 1705z. Also during the support, JPL COMM switched to the MDSCC Back-Up NTR circuit at 1711z, which caused monitor data to stop flowing until JPL switched back to the MDSCC Prime NTR circuit at 1719z. The turbo decoder anomaly resulted in the loss of 17 frames of SSR data. See DRs# N108410 and N108407 for more information. The JPL COMM switches on Sep 12 and 13 were unplanned activities. * On day 258 (Sep 14), during the DSS-63 support for Behind, turbo decoder lock was lost briefly at 1318z. SSR pointers were repositioned to minimize data loss. All SSR data was recovered. See DR# N108411 for more information. * On day 259 (Sep 15), during the DSS-63 support for Behind, turbo decoder lock was lost intermittently beginning at 1023z through 1320z. This anomaly resulted in the loss of 25 frames of SSR data. See DR# N108412 for more information. * On day 260 (Sep 16), during the DSS-63 support for Behind, turbo decoder lock was lost briefly at 1204z. This anomaly resulted in the loss of one frame of SSR data. See DR# N108413 for more information. * The average daily SSR playback volume during the week was 4.5 gigabits for Ahead, and 4.9 gigabits for Behind. * A question was raised about whether the recent broadening of the station receiver bandpass made any difference in the occasional losses of turbo decoder lock. Increasing the bandpass would make the system more robust in case of problems with the Doppler acceleration. However, the change appears to have made no difference. It appears that the problem is in slight variations in the phase in the Receiver Ranging Process (RRP). DSN will continue to monitor the situation. The Madrid station will have passes with two downlink channels open to help pinpoint the problem. Week 38 (Sep 17-23) * The 23rd SECCHI stepped calibration roll on Ahead was carried out this morning (Sep 18). * 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 Thursday, 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. Week 41 (Oct 8-14) * Ahead has 70 meter passes on Monday, Oct 8 (D14), Tuesday, Oct 9 (D14), Wednesday, Oct 10 (D14), Friday, Oct 12 (D14), Saturday, Oct 13 (D63, D43), and Sunday, Oct 14 (D63). There are 11 passes during the week, and overall coverage is nominal. * Behind has 70 meter passes on Tuesday, Oct 9 (D14), Thursday, Oct 11 (D43 at 720 kbps), Friday, Oct 12 (D43), Sunday, Oct 14 (D63, D43). The D34 pass on Friday Oct 12 will be stepped to 240 kbps. There are 9 passes during the week, and overall coverage is nominal. Week 42 (Oct 15-21) * Ahead has 70 meter passes on Monday, Oct 15 (D14), Wednesday, Oct 17 (D63), Saturday, Oct 20 (D63, D14), and Sunday, Oct 21 (D63). There are 14 passes during the week, and overall coverage is nominal. * Behind has 70 meter passes on Monday, Oct 15 (D43, D14), Tuesday Oct 16 (D14), Wednesday, Oct 17 (D63), Thursday, Oct 18 (D14), Saturday, Oct 20 (D14) and Sunday, Oct 21 (D63). There are 8 passes during the week, and overall coverage is nominal. An ESA New Norcia pass is scheduled for Friday, Oct 19. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- 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. ------------------------------------------------------------------------------- Scheduled activities for Week 41: M Oct 08 (282) T Oct 09 (283) W Oct 10 (284) T Oct 11 (285) F Oct 12 (286) S Oct 13 (287) S Oct 14 (288) ------------------------------------------------------------------------------- Scheduled activities for Week 42: M Oct 15 (289) T Oct 16 (290) W Oct 17 (291) T Oct 18 (292) F Oct 19 (293) S Oct 20 (294) S Oct 21 (295) ------------------------------------------------------------------------------- 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