STEREO Weekly Meeting Minutes for 2009-11-24 (Week 48) ANNOUNCEMENTS ------------- * Tests will be made of the 240 kbps and 120 kbps telemetry rates on Behind on Nov 30 and Dec 1. Details are below. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 47 * Telemetry lock was lost intermittently during the Ahead pass on station 55 on day 322 (Nov 18). A total of 35 frames were lost. * The EEPROM on IMU #1 on Behind was refreshed on day 321 (Nov 17). * The average daily SSR downlink was 6.6 gigabits on Ahead, and 5.6 gigabits on Behind. Week 48 * Telemetry lock was lost intermittently during the Ahead pass on station 54 yesterday (Nov 23), resulting in the loss of several frames. * The 11th SECCHI stepped calibration roll on Ahead was carried out this morning (Nov 24), starting at 14:15 UT. Ahead will reach aphelion on Nov 25 at 05:38 UT. * The macro changes needed for the switch to 240 kbps have been loaded on Behind. * Thanksgiving is Thursday, Nov 26. Friday is also a holiday for APL. * Short tracks are scheduled for Ahead on Wednesday, Nov 25, and on Behind on Nov 23. Week 49 * The EEPROMs on Ahead on both IMUs 1 and 2 will be refreshed on Dec 1, starting at 14:00 UT. This should not affect the instruments. * The 26th momentum dump will be carried out on Ahead on Wednesday, Dec 2, starting at 17:30 UT. * Behind will switch to 7 hour tracks in preparation for the switch down to 240 kbps. Not all the tracks will be 7 hours in duration, but this will be made up for to some extent by occasionally having additional tracks. * Tests will be made of the 240 and 120 kbps telemetry rates during the 5 hour Behind pass on station 65 on Monday, Nov 30. A test schedule has been distributed. Testing at the 240 kbps rate will begin at 18:00 UT, followed by testing at 120 kbps starting at 19:00 UT. No SSR data will be played back during the testing. There will be a 3 hour track starting at 1 UT on Dec 1 for SSR playback. The following 7 hour track will be an additional test of the 240 kbps, including SSR playback. * There was some discussion about what changes, if any, the instrument teams needed to make to support the playback tests. It was decided that no changes were required of the instrument teams. The lowered realtime rates will be implemented by APID. SECCHI has already lowered their realtime housekeeping rate to be compatible with the 240 kbps downlink rate. * The instrument teams should examine the realtime telemetry during the tests, to confirm that the system behaved as expected. Week 50 * Behind will switch to the 240 kbps rate on Dec 8, starting with the pass beginning at 14:20 UT on station 55. Ahead will remain at 360 kbps until April. Week 51 * No significant activities planned. Other * APL asked about the status of switching the beacon telemetry mode to Turbo. This depends on software development by NOAA, who reports that this is turning out to be harder than anticipated. NOAA does not have many resources to devote to this issue, and progress is not anticipated any time in the foreseeable future. NOAA is also pursuing the question of whether changing the beacon modulation index will increase the signal to noise. * The question was raised as to how long the beacon stations can continue to operate without switching to Turbo mode. An earlier analysis showed that stations of ~10 meters in size should continue to collect beacon data all the way out to 2 A.U. in Turbo mode, but it's unclear how far out coverage will be maintained without switching to Turbo. One 4.5 meter station in England has already dropped out of the network because of the degradation in signal-to-noise. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 48: M Nov 23 (327) T Nov 24 (328) Ahead: SECCHI stepped calibration roll, 14:15 W Nov 25 (329) T Nov 26 (330) Thanksgiving F Nov 27 (331) S Nov 28 (332) S Nov 29 (333) ------------------------------------------------------------------------------- Scheduled activities for Week 49: M Nov 30 (334) Behind: Begin 7 hour daily DSN tracks T Dec 01 (335) W Dec 02 (336) Ahead: momentum dump, 17:30 UT T Dec 03 (337) F Dec 04 (338) S Dec 05 (339) S Dec 06 (340) ------------------------------------------------------------------------------- Scheduled activities for Week 50: M Dec 07 (341) Behind: Switch downlink rate to 240 kbps T Dec 08 (342) W Dec 09 (343) T Dec 10 (344) F Dec 11 (345) S Dec 12 (346) S Dec 13 (347) ------------------------------------------------------------------------------- Scheduled activities for Week 51: M Dec 14 (348) T Dec 15 (349) W Dec 16 (350) T Dec 17 (351) F Dec 18 (352) S Dec 19 (353) S Dec 20 (354) ------------------------------------------------------------------------------- Upcoming events: 2009: ICAL-001: Dec 14-18 SECCHI Stepped calibration rolls Ahead: Nov 24 Behind: Dec 22 * Ongoing JOP 222, Origin of SEPS, Target of opportunity 2010: ICAL-001: Jan 11-15, Feb 15-19, Mar 15-19, Apr 12-16, May 3-7 SECCHI Stepped calibration rolls Ahead: Feb 23, May 18, Aug 10, Nov 2 Behind: Apr 6, Jul 13, Oct 12 * Jan 6 Both: HGA calibration * Jan 7,15 EIT shutterless (TBC) * Spring (TBD) SUMI sounding rocket launch http://adsabs.harvard.edu/abs/2008AGUSMSP51B..01A * Apr 8,15 EIT shutterless (TBC) * Apr 19 Ahead: Begin 7 hour daily DSN tracks * Apr 26 Ahead: Switch downlink rate to 240 kbps * Jul 8,15 EIT shutterless (TBC) * Jul 11 Total solar eclipse http://eclipse.gsfc.nasa.gov/SEmono/TSE2010/TSE2010.html * Jul 14 Both: HGA calibration * Sep 7 Both: Begin 8 hour daily DSN tracks * Sep 13 Both: Switch downlink rate to 160 kbps * Nov 15 Behind: Switch downlink rate to 120 kbps 2011: * Jan 12 Both: HGA calibration * Feb 6 STEREO spacecraft at 180 degree separation * Mar 18 Messenger - Mercury orbital insertion * Apr 11 Ahead: Switch downlink rate to 120 kbps * Jul 13 Both: HGA calibration * Aug DAWN - Vesta arrival * Sep 19 Behind: Switch downlink rate to 96 kbps * Sep 26 Ahead: Switch downlink rate to 96 kbps 2012: * Jan 11 Both: HGA calibration * May DAWN - Vesta departure * Jul 11 Both: HGA calibration * Aug Both: Switch downlink rate to 30 kbps * Nov 13 Total solar eclipse, south Pacific 2013: * Dec 12 Ahead: Possible Mercury transit (TBC) 2014: * Apr 29 Behind: Possible Mercury transit (TBC) 2015: * Feb DAWN - Ceres arrival * Jan 10 - Apr 12 Behind: Spacecraft behind Sun * Feb 17 - Aug 2 Ahead: Spacecraft behind Sun * Jul 23 - Nov 10 Behind: Spacecraft behind Sun * Jul DAWN - End of nominal mission