STEREO Weekly Meeting Minutes for 2009-05-19 (Week 21) ANNOUNCEMENTS ------------- * Access to the STEREO MOC via the internet will be unavailable from 6:00 A.M to noon EDT (10-16 UT) on Saturday, May 30. No real-time telemetry or instrument commanding will be available through the internet. It is recommended that the instruments use the backup modem capability. If required, this should be tested in advance. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal, except that the Ahead spacecraft is currently operating on IMU #2. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 20 * The station 25 antenna brakes were set for 39 minutes during the Ahead pass on day 134 (May 14), starting at 13:09 UT. This resulted in SSR data loss for all instruments. * The 21st momentum dump was carried out on Ahead on day 132 (May 12), starting at 13:30 UT. A delta-V of 0.0716 m/s was imparted. * Flight software version 4.10 was uploaded to SWAVES-Ahead on day 134 (May 14), but is not yet activated. * Telemetry lock was lost momentarily during the station 34 pass for Behind on day 131 (May 11). Three SSR telemetry frames were lost. * On day 132 (May 12), a backup pass on station 26 was arranged for day 133 (May 13) to mitigate a possible azimuth antenna brake during the station 14 support for the Behind reset and recovery. No problems were seen during the station 14 pass, and this backup pass was not used. * During the Behind spacecraft reset and recovery on station 14, the receiver initially did not lock up on the emergency data rate telemetry from the low gain transmitter on day 133 (May 13). DSN switched to the redundant channel, and lock was achieved. * The Behind spacecraft reset on day 132 (May 12) was successfully executed. IMPACT and PLASTIC powered down their high voltages during the station 65 pass prior to the reset pass. The instruments were then powered down 5 minutes apart at the start of the station 14 pass. All instruments were powered down by 23:10, and the spacecraft received the command to reset at 23:37 UT. The recovery operation was nominal, and all systems and instruments weree back up by 04:18 UT. The SECCHI and SWAVES instruments were back to their nominal operating condition and taking data by the end of the track. * Configuration continued during the following track on station 14 on day 133 (May 13). PLASTIC and IMPACT SWEA were brought back to their nominal operating state. IMPACT SEP configuration was completed on day 136 (May 16) at 03:05 UT. * SWAVES flight software version 4.10 was uploaded to Behind during the station 14 pass on day 133 (May 13), but is not yet activated. * The average daily downlink was 5.9 gigabits on Ahead, and 5.0 on Behind. * The SWAVES team comments that they saw a funny 20 minute gap around 17:00 on Behind on day 133 (May 13). The gap was strange because a few packets were received in the middle of the gap, and there were indications of activity in the SWAVES data during the gap. It was theorized that this gap is due to the antenna brake problem on station 14 due to low film height. APL will look into whether more telemetry is available. Week 21 * Realtime telemetry was lost early on Monday (May 18) during the Ahead pass on station 65. All data was received on the ground. * The new SWAVES flight software will be activated tomorrow (May 20) on both spacecraft. The Ahead pass starts around 3:00 EDT in the afternoon, and the Behind pass around noontime. Week 22 * Monday is Memorial Day. * The fourth HI 180 degree rolls are scheduled for both Ahead and Behind on day 147 (May 27). The Ahead roll will start at 13:50 and the Behind roll will start at 17:50. The system momentum will be about 6 N-m-s on Ahead, and 7 N-m-s on Behind. The rolls are about 7 hours in duration. * Internet connectivity to APL will be unavailable for six hours on Saturday, May 30. See the announcement above for more details. Week 23 * The 16th momentum dump on Behind is scheduled for June 4th, starting at 15:00 UT. * The Ahead pass on Thursday, June 4 is shorter than usual (3 hours). Other * No date has been set yet for the reset on Ahead. This is expected to occur sometime in August, possibly in the first week. * The SWAVES team points out that there have been an unusual number of telemetry file versions lately for Ahead. APL reports that they found multiple instances of the automated processing program running, which explains the extra versions. * The LRO launch date has been moved to June 17. The impact on the STEREO DSN schedule is not yet known. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 21: M May 18 (138) T May 19 (139) W May 20 (140) T May 21 (141) ICAL-1, 14 UT F May 22 (142) S May 23 (143) S May 24 (144) ------------------------------------------------------------------------------- Scheduled activities for Week 22: M May 25 (145) T May 26 (146) W May 27 (147) SECCHI HI 180 degree rolls, Ahead: 13:50, Behind: 17:50. T May 28 (148) F May 29 (149) S May 30 (150) S May 31 (151) ------------------------------------------------------------------------------- Scheduled activities for Week 23: M Jun 01 (152) T Jun 02 (153) W Jun 03 (154) T Jun 04 (155) Behind: Momentum dump, 15:00 UT F Jun 05 (156) S Jun 06 (157) S Jun 07 (158) ------------------------------------------------------------------------------- Upcoming events: 2009: ICAL-001: May 11-22, Jun 15-19, Jul 13-17, Aug 17-21, Sep 14-18, Oct 12-16 SECCHI Stepped calibration rolls Ahead: Jun 9, Sep 2, Nov 24 Behind: Jun 16, Sep 22, Dec 22 * Mar 16-Sep LASCO C2pB for Tomography Reconstruction * Mar 27-... JOP 222, Origin of SEPS, Target of opportunity * Jun 1-Jul 10 Sunrise 5-day balloon flight http://star.mpae.gwdg.de/Sunrise/project/publicat/SPIE_2004.pdf * Jul 1 Both: HGA calibration * Jul 21 (TBC) ICAL14, Herschel sounding rocket launch, 19:10 UT http://sohowww.nascom.nasa.gov/soc/JOPs/ical014-draft.pdf * Jul 22 Total solar eclipse http://eclipse.gsfc.nasa.gov/SEmono/TSE2009/TSE2009.html * Jul 28 (TBC) SUMI sounding rocket launch http://adsabs.harvard.edu/abs/2008AGUSMSP51B..01A * Aug 10 Both: Begin 6 hour daily DSN tracks * Aug 17 Ahead: Switch downlink rate to 360 kbps * Sep 8 Behind: Switch downlink rate to 360 kbps * Sep 10 Ahead at L4 Lagrange point * Sep 29 Messenger - Mercury fly-by * Oct 26 Behind at L5 Lagrange point * Nov 1-Dec 15 SUMER campaign (TBC) * Nov 30 Behind: Begin 7 hour daily DSN tracks * Dec 7 Behind: Switch downlink rate to 240 kbps 2010: 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 * Apr 19 Ahead: Begin 7 hour daily DSN tracks * Apr 26 Ahead: Switch downlink rate to 240 kbps * 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 * 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 2013: 2014: 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