STEREO Weekly Meeting Minutes for 2014-09-02 (Week 36) ANNOUNCEMENTS ------------- * None. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. Ahead is operating on the first side lobe of the HGA to prevent overheating of the feed assembly. The star tracker on Ahead is currently in standby mode after a reset on Sep 1 caused by a large flux of high energy particles. See below for details. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 35 (Aug 25-31) * On day 237 (Aug 25), during the DSS-25 support for Ahead, side lobe communications were tested with a DSN 34 meter station on the Ahead observatory. At the low downlink rate of 633 bps and 30 degrees elevation, there was ~8 dB downlink margin on the first side lobe and ~2 dB on the second side lobe. Commanding was successful on both side lobes at 125 bps. With the successful confirmation of this 34m test, the project now considers the 34m subnet viable for emergency use as well as occasional spacecraft bus checks. * On day 241 (Aug 29), the 71st momentum dump on Ahead was executed successfully at 0030z, which imparted a delta V of 0.098 m/sec. * On days 235 and 236 (Aug 23-24), IDR files for Behind did not make it into the archive, resulting in gaps in spacecraft and instrument data. The missing files were re-transmitted on 238, and new versions of data products were regenerated. * On day 237 (Aug 25), during the DSS 14 track for Behind, turbo decoder lock was lost briefly at 1507z. SSR pointers were re-positioned and all SSR data were received. * On day 242 (Aug 30), during the DSS-26 support for Behind, initial telemetry lock was established two minutes late at 1512z due to the Automated Link Build at the station not being able to configure for the support. No command uplink was available as the transmitter remained red for the duration of the support. See DR #G115400 for more information. * On day 237 (Aug 25), the 66th momentum dump on Behind was executed successfully at 1830z, which imparted a delta V of 0.074 m/sec. * On day 239 (Aug 27), the Data Handling 1.1.8 and Power 1.0.3 parameter releases were loaded to C&DH EEPROM on Behind in preparations for Behind solar conjunction testing to commence on day 270 (Sep 27). * The average daily SSR playback volume for the week was 0.086 gigabits for Ahead, and 4.8 gigabits for Behind. * The current HGA feed temperature is 101 C on Ahead at an antenna angle of 9.9 degrees, and 95 C on Behind, at an antenna angle of 9.4 degrees. * SWAVES reports that they don't see any of their prime-mode data on Ahead from Aug 29 onward. IMPACT reports that they disabled a feature on their IDPU around that time that was interfering with sending telemetry due to their partitition being full. Since this turned on their science data, there may be a connection with the lack of SWAVES-prime data. Week 36 (Sep 1-7) * Star trackers on both spacecraft reset yesterday (Sep 1) within minutes of each other, due to a high level of energetic particles. * The star tracker on Behind reset at 15:44 UT yesterday (Sep 1) during the station 26 support. After the star tracker failed to promote back to operating mode, IMU-A powered on. Later, telemetry lock was dropped due to the pointing offset, and 1.5 hours of the track was lost. This morning, during the station 54 pass, it was established that the star tracker came promoted back to operational mode at 20:26 UT yesterday (Sep 1), after 4.7 hours. The IMU was commanded off, after being on for 19.5 hours. This is the second star tracker reset on Behind. * That the star tracker on Ahead also reset wasn't known until the pass this morning. Because the pointing tolerances on the HGA side lobe are much tighter, it took a while to acquire the signal. Once the signal was established, it was determined that the star tracker reset at 15:28 UT yesterday (Sep 1), and IMU-B was powered up at 15:29 UT. The star tracker is still in standby mode. An ESA Malargue track has been added for 11:40 UT tomorrow (Sep 3) to assist in recovery of the star tracker. This is the fifth star tracker reset on Ahead. * The autonomy rule to turn the IMU off after the star tracker has recovered has not yet been uploaded to either spacecraft. * SECCHI needs to get some commands up tomorrow (Sep 3). This should be possible during the station 14 track starting at 15:25 UT. * The MESSENGER spacecraft also saw some anomalies over the weekend, including a star tracker reset. * G&C parameters 1.3.1 will be loaded to EEPROM on Behind on Tuesday, Sep 2. * Ahead has 8 passes during the week, all at 10 kbps on the first side lobe, in IMPACT-prime mode. * 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, in SWAVES-prime mode. * 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. Week 38 (Sep 15-21) * There will be a readiness review on Thursday, Sep 18, for the Behind testing. * Ahead has 7 passes during the week, all at 10 kbps on the first side lobe, in IMPACT-prime mode. * Behind has 13 passes during the week, and overall coverage is nominal. There are two passes at 720 kbps, four passes at 160 kbps, and seven passes at 120 kbps. Week 39 (Sep 22-28) * Macros and rules will be written to EEPROM and RAM on Behind from Tuesday to Friday, Sep 23-26. EA mode bypass will be enabled on Thursday, Sep 25. * Solar conjunction testing will start on Saturday, Sep 27. A more detailed schedule has been distributed. Instruments will be turned off by 18 UT, with the exception of SWAVES which will remain on. SWAVES will be powered cycled twice during the test. POC queues will be open on Friday for instrument commanding. Testing will include reconfiguration of the SSR. * On Sunday, Sep 28, the HGA angle bias will be switched to the first side lobe. The 67th momentum dump will be carried out during the station 14 pass on the first side lobe, starting at 16:30 UT, with a lower target of 8 N-m-s as will be used during solar conjunction. The commands for the momentum dump will be loaded during the previous pass. The spacecraft will be commanded to reset at 17:30 UT, and will come up at 633 bps, and slowly rotating at 5 degrees/minute. * Ahead has 7 passes during the week, all at 10 kbps on the first side lobe, in SWAVES-prime mode. * Behind has 13 passes during the week, and overall coverage is nominal. There are two passes at 720 kbps, four passes at 160 kbps, and seven passes at 120 kbps. ESA New Norcia passes are scheduled for Monday, Sep 22, and Wednesday, Sep 24. Week 40 (Sep 29-Oct 5) * A momentum dump on Ahead will be carried out on Tuesday, Sep 30, with ignition at 22:00 UT. The commands for the momentum dump will be loaded during the previous pass. * Solar conjunction testing on Behind will continue during the week. The earlier testing on Ahead concentrated on the process of going into solar conjuction. These tests will concentrate on the process of coming out. The recorder is also reconfigured during these tests, which was not done during the Ahead testing. * During the first pass on Monday, Sep 29, the MOC will watch the spacecraft rotate. At 05:30 UT a macro will put the spacecraft into 3-axis stabilized mode. * On Tuesday, Sep 30, the 48 hour fault protection rule will trigger at 17:30 UT, switching to the -Z LGA. * On Wednesday, Oct 1, Behind the soft command load timer will trigger at 5:30 UT, switching to the +Z LGA, and start the spacecraft slowly rotating. Station 14 will acquire the signal at 15:30, at 12 bps, and will watch the spacecraft rotate. At 17:50, the 3 day hard command loss timer will trigger, resetting the spacecraft, and setting it back to 3 axis stabilized on the second side lobe. It will then be commanded to a 1 degree offset at 120 kbps, and spacecraft will be reconfigured back to operational mode. * On Thursday, Oct 2, the spacecraft will come up at a 1 degree offset, and will be commanded back to the center of the main lobe. Instrument power on is expected to begin during the station 36 support starting at 15:30 UT. An ESA New Norcia support is also available later in the day, as well as another DSN support and an ESA New Norcia support on Friday. The remainder of the passes during the week will be using 70 meter stations. * Ahead has 9 passes during the week, all at 10 kbps on the first side lobe, in IMPACT-prime mode. * Behind has 13 passes during the week, and overall coverage is nominal. There are three passes at 720 kbps, one pass at 160 kbps, six passes at 120 kbps, two passes at 0.633 kbps, and one pass at 0.012 kbps. ESA passes have been scheduled for Thursday and Friday, Oct 2-3. Week 41 (Oct 6-12) * Ahead has seven passes during the week, all at 10 kbps on the first side lobe, in SWAVES prime mode. * Behind has 13 passes during the week, and overall coverage is nominal. There are five passes at 720 kbps, two passes at 160 kbps, and six passes at 120 kbps. An ESA New Norcia pass is scheduled for Wednesday, Oct 8. Week 42 (Oct 13-19) * Ahead has eight passes during the week, all at 10 kbps on the first side lobe, in IMPACT prime mode. * Behind has 12 passes during the week, and overall coverage is nominal. There are three passes at 720 kbps, three passes at 160 kbps, and six passes at 120 kbps. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 36: M Sep 01 (244) Labor Day 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: * Ahead operating on first side lobe, in IMPACT-prime mode. * 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: * Ahead operating on first side lobe, in SWAVES-prime mode. * Passage of Comet Siding Spring through HI2 on Behind, Sep 07-Nov 15 ------------------------------------------------------------------------------- Scheduled activities for Week 38: M Sep 15 (258) T Sep 16 (259) W Sep 17 (260) T Sep 18 (261) F Sep 19 (262) S Sep 20 (263) S Sep 21 (264) MAVEN arrival at Mars Notes: * Ahead operating on first side lobe, in IMPACT-prime mode. * Passage of Comet Siding Spring through HI2 on Behind, Sep 07-Nov 15 ------------------------------------------------------------------------------- Scheduled activities for Week 39: M Sep 22 (265) T Sep 23 (266) W Sep 24 (267) T Sep 25 (268) F Sep 26 (269) S Sep 27 (270) Behind: Instruments off for solar conjunction testing, 18 UT (except SWAVES) S Sep 28 (271) Behind: Switch to first side lobe. Momentum dump, 16:30 UT. Spacecraft reset at 17:30 UT, come up at 633 bps, rotating 5 degrees/minute. Notes: * Test of solar conjunction operations on Behind, Sep 27-Oct 3 * Ahead operating on first side lobe, in SWAVES-prime mode. * Passage of Comet Siding Spring through HI2 on Behind, Sep 07-Nov 15 ------------------------------------------------------------------------------- Scheduled activities for Week 40: M Sep 29 (272) Behind: Solar conjunction testing continues Behind: Timed command to 3-axis stabilized, 5:30 UT T Sep 30 (273) Behind: Switch to -Z LGA, 17:30 UT Ahead: Momentum dump, 22:00 UT W Oct 01 (274) Behind: Switch to +Z LGA and start rotating, 5:30 UT Hard command loss timer, 17:50, switch to 3 axis stab. Switch from 2nd side lobe to 1 degree offset, 120 kbps T Oct 02 (275) Behind: Command back to 0 degree offset on main lobe. Recover spacecraft, start powering instruments back on. F Oct 03 (276) Behind: Continue recovery as needed S Oct 04 (277) S Oct 05 (278) Notes: * Test of solar conjunction operations on Behind, Sep 27-Oct 3 * Ahead operating on first side lobe, in IMPACT-prime mode. * Passage of Comet Siding Spring through HI2 on Behind, Sep 07-Nov 15 ------------------------------------------------------------------------------- Scheduled activities for Week 41: M Oct 06 (279) T Oct 07 (280) W Oct 08 (281) T Oct 09 (282) F Oct 10 (283) S Oct 11 (284) S Oct 12 (285) Notes: * Ahead operating on first side lobe, in SWAVES-prime mode. * Passage of Comet Siding Spring through HI2 on Behind, Sep 07-Nov 15 ------------------------------------------------------------------------------- Scheduled activities for Week 42: M Oct 13 (286) T Oct 14 (287) W Oct 15 (288) T Oct 16 (289) F Oct 17 (290) Behind: Comet Siding Spring encounter with Mars S Oct 18 (291) S Oct 19 (292) Notes: * Ahead operating on first side lobe, in IMPACT-prime mode. * 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 * 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, both side lobes 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