STEREO Weekly Meeting Minutes for 2014-07-29 (Week 31) ANNOUNCEMENTS ------------- * None. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 30 (Jul 21-27) * On day 203 (Jul 22), during the DSS-63 support for Ahead, turbo decoder lock was lost briefly at 1033z. This anomaly resulted in the loss of one frame of SSR data. * On day 206 (Jul 25), the HGA soft stop on Ahead was reduced from 8.1 to 7.1 degrees in G&C RAM. Since July 2, 2014, the HGA feed temperature has been rising slower than previously observed or predicted. The above change will allow the HGA to follow the declining SPE angle up to August 20, 2014, when side lobe operations will commence. During this period, the HGA feed temperature will continue to be monitored closely. This will allow additional data to be collected at lower SPE angles to recover the HGA to the main lobe sooner post solar conjunction. If there are any problems with the temperature, the HGA soft stop will be changed back. * The current HGA feed horn temperature is 113 degrees C on Ahead, at an SPE angle of 8.05 degrees, and 101 degrees C on Behind, at an SPE angle of 9.15 degrees. * On day 203 (Jul 22), during the DSS-55 support for Behind, turbo decoder lock was lost briefly at 0910z. This anomaly resulted in the loss of four frames of SSR data. * On day 203 (Jul 22), during the setup for the DSS-14 support for Behind, the pre-track ranging calibration failed. A ranging post-track calibration was performed. See DR #G115260 for more information. * On day 204 (Jul 23), a project interface test with Behind was conducted successfully with DSS-35, the new 34m BWG antenna at the DSN Canberra complex, at 2330z. The MOC successfully bound with telemetry server and with the station for commanding, received spacecraft telemetry with a good SNR, and sent 31 commands to the Behind observatory, from all three MOC command workstations. * On day 206 (Jul 25), during the DSS-24 support for Behind, acquisition of telemetry occurred 14 minutes late at 2314z due to fault isolation from an uplink anomaly. The track remained downlink only. SSR pointers were repositioned on the next support with DSS-55 at 207-0840z to recover lost data. This anomaly resulted in the loss of all commanding and two-way tracking data and one frame of SSR data. See DR #G115274 for more information. * On day 208 (Jul 27), during the DSS-54 support for Behind, acquisition of telemetry occurred 54 minutes late at 1059z due to an antenna pointing anomaly. SSR pointers were repositioned to recover lost data. All SSR data were recovered. See DR #M108195 for more information. * On day 208 (Jul 27), a project interface (return-to-service) test was conducted successfully at 1800z with DSS-26, after installation of an 80 kW transmitter. The MOC received spacecraft telemetry at the 160 kbps downlink rate with a good SNR and sent two commands to the Behind observatory. Telemetry lock was lost at 1924z for 11 minutes due to receiver issue. See DR #G115277 for more information. * The average daily SSR playback volume during the week was 4.9 gigabits for Ahead, and 4.3 gigabits for Behind. Week 31 (Jul 28-Aug 3) * C&DH flight software version 3.2.4 will be written to EEPROM copy 1 on Ahead on Jul 29. This is already in copy 2. * Telemetry tables and MOps macros will be uploaded on Friday, Aug 1, in preparation for the real-time side lobe test the following week. * The 65th momentum dump on Behind was carried out yesterday (Jul 28). The COR1 and COR1 doors remain closed since the momentum dump. The next opportunity to close them is pass tomorrow (Jul 30) starting at 7:10 UT. SECCHI raised the possibility of sending up a few commands to open the doors during the D35 PIT test starting at 1:00 UT. Their concern is that the COR1 and COR2 temperatures rise with the door closed, and an autonomy rule may disable these telescopes if the temperatures get too high. It was agreed that SECCHI may attempt to command their doors open during the PIT test. If this is unsuccessful, the doors can be opened during the later pass at 7:10 UT. * A 3 hour Project Interface Test (PIT) will be carried out on Behind with station 35 on Jul 30. There will be no instrument commanding or SSR playback during this pass. (However, see above.) * An HGA side lobe test with the Behind spacecraft will be carried out on Sunday, Aug 3, starting at 17:00 UT. * Ahead has 10 passes during the week, and overall coverage is nominal. There is one pass at 720 kbps, one pass at 480 kbps, one pass at 240 kbps, six passes at 160 kbps, and one pass at 120 kbps. * Behind has 10 passes during the week, and overall coverage is nominal. There are five passes at 720 kbps, and five passes at 120 kbps. Week 32 (Aug 4-10) * Although the soft stop angle for the HGA antenna on Ahead has been adjusted, the lower telemetry rates will continue to be used, in case the soft stop angle has to be increased. * The 70th momentum dump on Ahead will be carried out on Aug 4, with ignition at 18:00 UT. * A test of uploading a long term ephemeris to the Ahead spacecraft is scheduled for Tuesday, Aug 5. * A test of the side lobe telemetry rates will be carried out on Wednesday, Aug 6, starting at 16:30 UT. A detailed timeline has been distributed to the instrument teams. The HGA antenna will be at the nominal pointing--only the telemetry rates will be tested. The test will include the 1 degree offpoint, first side lobe, and second side lobe telemetry rates. Instruments can resume their normal telemetry rates at the end of track. IMPACT, PLASTIC, and SECCHI will be commanding during the previous track. SECCHI will also need to send up a command to adjust their beacon telemetry rate for the second side lobe. * C&DH flight software version 3.2.4 will be written to EEPROM copy 2 on Behind. * Ahead has 10 passes during the week, and overall coverage is nominal. There are seven passes at 720 kbps, one pass at 240 kbps, and two passes at 96 kbps, on Aug 6 and 9. * Behind has 10 passes during the week, and overall coverage is nominal. There are five passes at 720 kbps, three passes at 240 kbps, one pass at 160 kbps, and one pass at 120 kbps. Week 33 (Aug 11-17) * The 4th battery discharge/charge cycle on Ahead will be Aug 14. This will not affect science operations. * The 31st SECCHI stepped calibration roll will be on Saturday, Aug 16, starting at 17:50 UT. * Additional preparations will be made on the Behind spacecraft for side lobe operations. * Ahead has 8 passes during the week, all at 480 kbps, and overall coverage is nominal. * Behind has 13 passes during the week, and overall coverage is nominal. There are three passes at 720 kbps, one pass at 240 kbps, two passes at 160 kbps, and seven passes at 120 kbps. Week 34 (Aug 18-24) * The Ahead reconfiguration for side-lobe operations will be loaded on Tuesday Aug 19. Final mission operation macros and the HDA angle bias will be loaded. The SSR will be reconfigured. Ahead operations on the first side lobe will start Aug 20. * Ahead has 8 passes during the week, and overall coverage is nominal. There are two passes at 360 kbps (Monday and Tuesday). On Aug 20th first side lobe coverage will begin and be at 10 kbps. This will continue until around Nov 10 when operations on the second side lobe will bring this down to 3 kbps. * Behind has 14 passes during the week, with nominal coverage overall. Three tracks are at 720 kbps, one at 160 kbps and nine at 120 kbps. Week 35 (Aug 25-31) * Ahead will be operating with the high gain antenna on its first side lobe. * A test of using a 34 meter station at 633 bps with Ahead will be carried out on Monday, Aug 25. * The 66th momentum dump for Behind is Monday, Aug 25 at 18:30 UT. * Ahead has 8 passes, all at 10 kbps, for nominal coverage. * Behind has 11 passes during the week, and overall coverage is nominal. Six passes are at 720 kbps, one at 240 kbps, two at 160 kbps and two at 120 kbps. Week 36 (Sep 1-7) * Preparations of Behind for solar conjunction operations will continue. * Ahead has 8 passes during the week, all at 10 kbps on the first side lobe. * Behind has 13 passes during the week, and overall coverage is nominal. There are two passes at 720 kbps, three passes at 160 kbps, and eight passes at 120 kbps. Week 37 (Sep 8-14) * Ahead has 7 passes during the week, all at 10 kbps on the first side lobe. * Behind has 12 passes during the week, and overall coverage is nominal. There are two passes at 720 kbps, two passes at 160 kbps, and eight passes at 120 kbps. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 31: M Jul 28 (209) Behind: Momentum dump, 19:45 UT T Jul 29 (210) Behind: COR1,COR2 doors closed due to scheduling error W Jul 30 (211) Behind: Project interface test with new 34 meter station D35 T Jul 31 (212) F Aug 01 (213) S Aug 02 (214) S Aug 03 (215) Behind: Operational HGA Side Lobe Test ------------------------------------------------------------------------------- Scheduled activities for Week 32: M Aug 04 (216) Ahead: Momentum dump, 18:00 UT T Aug 05 (217) W Aug 06 (218) Ahead: Test of side lobe telemetry rates, 16:30 UT T Aug 07 (219) F Aug 08 (220) S Aug 09 (221) S Aug 10 (222) ------------------------------------------------------------------------------- Scheduled activities for Week 33: M Aug 11 (223) T Aug 12 (224) W Aug 13 (225) T Aug 14 (226) Ahead: Solar Conjunction Readiness Review Ahead: Battery conditioning F Aug 15 (227) S Aug 16 (228) Ahead: SECCHI stepped calibration roll, 17:50 UT (aphelion) S Aug 17 (229) ------------------------------------------------------------------------------- Scheduled activities for Week 34: M Aug 18 (230) T Aug 19 (231) Ahead: SSR reconfiguration W Aug 20 (232) Ahead: HGA on 1st side lobe T Aug 21 (233) F Aug 22 (234) S Aug 23 (235) S Aug 24 (236) ------------------------------------------------------------------------------- Scheduled activities for Week 35: M Aug 25 (237) Ahead: Test with 34 meter at 633 bps Behind: Momentum dump, 18:30 UT T Aug 26 (238) W Aug 27 (239) T Aug 28 (240) F Aug 29 (241) S Aug 30 (242) S Aug 31 (243) ------------------------------------------------------------------------------- Scheduled activities for Week 36: M Sep 01 (244) T Sep 02 (245) W Sep 03 (246) T Sep 04 (247) F Sep 05 (248) S Sep 06 (249) S Sep 07 (250) Notes: * Passage of Comet Siding Spring through HI2 on Behind, Sep 07-Nov 15 ------------------------------------------------------------------------------- Scheduled activities for Week 37: M Sep 08 (251) T Sep 09 (252) W Sep 10 (253) T Sep 11 (254) F Sep 12 (255) S Sep 13 (256) S Sep 14 (257) Notes: * Passage of Comet Siding Spring through HI2 on Behind, Sep 07-Nov 15 ------------------------------------------------------------------------------- Upcoming events: 2014: * Sep 07-Nov 15 Behind: Passage of Comet Siding Spring through HI2-B * Sep 21 MAVEN arrival at Mars * Sep 29-Oct 6 Behind: Test of solar conjunction operations * Oct 17 Behind: Comet Siding Spring encounter with Mars * Oct 23 Both: Solar Conjunction Readiness Review * Nov 10 Ahead: HGA on 2nd side lobe * Nov 17 Ahead: Test with 34 meter at 633 bps * Nov 19 Behind: HGA hits soft stop * Nov 28 Behind: SSR reconfiguration * Dec 1 Behind: HGA on 1st side lobe * Dec 8 Behind: Test with 34 meter at 633 bps 2015: * Jan 6 Behind: HGA on 2nd side lobe * Jan 12 Behind: Test with 34 meter at 633 bps * Jan 20 Behind: Instrument power down * Jan 22 - Mar 23 Behind: Spacecraft behind Sun * Mar DAWN - Ceres arrival * Mar 22 Ahead: Instrument power down * Mar 23 - Apr 06 Behind: S/C SSR Playback at 3 kbps * Mar 24 - Jul 07 Ahead: Spacecraft behind Sun * Mar 30 Behind: Instrument power on * Apr 25 Behind: HGA on 1st side lobe * Jul DAWN - End of nominal mission * Jul 8 Behind: HGA on 2nd side lobe * Jul 7-28 Ahead: S/C SSR Playback at 3 kbps * Jul 14 Ahead: Instrument power on * Sep 24 Ahead: HGA on 1st side lobe * Nov 20 Behind: HGA on 1st side lobe * Dec 29 Ahead: HGA on main lobe, offpoint 1 degree Ahead: SSR playback and reconfiguration, S/C checkout * Dec 31 Ahead: Instrument recommissioning 2016: * Jan 2 Behind: HGA on main lobe Behind: SSR playback and reconfiguration, S/C checkout * Jan 5 Behind: Instrument recommissioning * Jan 27 Both: HGA calibration * Feb 19 Ahead: HGA on main lobe * 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