STEREO Weekly Meeting Minutes for 2008-02-12 (Week 7) ANNOUNCEMENTS ------------- * Star tracker use will be suspended between tracks on Behind Feb 11-13, and on Ahead Feb 13-15 to collect data on the performance of the spacecraft without the star tracker. The test was shortened to minimize the effect on science. Sun pointing will still be controlled by the guide telescope, and only the roll should be affected. The roll should be maintained better than it was during the problems with the star tracker in December. It is expected that roll information in the attitude history files will be of sufficient accuracy for SECCHI data analysis, but it may be necessary to do some additional processing to get accurate roll values, such as processing the star tracker telemetry. INSTRUMENT AND SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal, except that the Ahead spececraft is currently operating on IMU #2. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 6 * The 11th momentum dump was performed on Ahead on day 37 (Feb 6), starting at 13:45 UT. The delta V was 0.064 m/s. * PLASTIC did a flight software load to Ahead on Thursday, day 38 (Feb 7). * The average daily downlink was 7.0 gigabits on Ahead, and 7.3 gigabits on Behind. * On day 38 (Feb 7), during the pass on Behind, station 26 lost ranging and commanding for 19 minutes due to an uplink exciter problem. * On day 39 (Feb 8), almost all of the station 35 pass on Behind was lost due to a Madrid power outage. This resulted in a SECCHI data gap from 21:07 to 08:06 the next day. * On day 40 (Feb 9), during the station 45 pass on Behind, the transmitter went offline. This had no effect on the pass, except that some ranging data may have been lost. Week 7 * Star tracker use is being suspended between tracks. See announcement above for details. * Macro updates will be written to EEPROM on both spacecraft on day 44 (Feb 13). * Behind will reach perihelion on day 47 (Feb 16). Week 8 * A SECCHI stepped calibration roll will be performed on Behind on day 50 (Feb 19) at 09:45 UT. Week 9 * Nothing unusual Week 10 * There will be a PLASTIC flight software load on Behind on day 63 (Mar 3). * There will be a power outage at APL on days 68-69 (Mar 8-9). The MOC will continue operating on the generator. * Daylight savings time in the U.S. starts March 9. Other * The MOC has been briefed by DSN on some upcoming interface changes. One change is in the way that scheduling is done, and will be implemented in the fall. The other is in the telemetry interface, which will occur toward the end of 2009. The MOC will also be switching to SLE for telemetry by February 2009. None of these changes should be visible to the instrument teams. * The Whole Heliospheric Interval will start March 20. This is a solar rotation of coordinated observations between many spacecraft and ground-based observatories, including STEREO. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 07: M Feb 11 (042) T Feb 12 (043) W Feb 13 (044) T Feb 14 (045) F Feb 15 (046) S Feb 16 (047) S Feb 17 (048) Notes: * Star tracker use will be disabled on Behind Feb 11-13, and Ahead Feb 13-15 ------------------------------------------------------------------------------- Scheduled activities for Week 08: M Feb 18 (049) T Feb 19 (050) Behind: SECCHI stepped calibration roll, 09:45 UT W Feb 20 (051) T Feb 21 (052) F Feb 22 (053) S Feb 23 (054) S Feb 24 (055) ------------------------------------------------------------------------------- Scheduled activities for Week 09: M Feb 25 (056) T Feb 26 (057) W Feb 27 (058) T Feb 28 (059) F Feb 29 (060) S Mar 01 (061) S Mar 02 (062) ------------------------------------------------------------------------------- Scheduled activities for Week 10: M Mar 03 (063) Behind: PLASTIC flight software load T Mar 04 (064) W Mar 05 (065) T Mar 06 (066) F Mar 07 (067) S Mar 08 (068) S Mar 09 (069) * Daylight savings time in U.S. starts March 9. ------------------------------------------------------------------------------- Upcoming events: 2008: SECCHI Stepped calibration rolls Ahead: Apr 1, Jun 24, Sep 23, Dec 16 Behind: May 20, Aug 26, Dec 2 * Dec 2007-May 2008 Ulysses quadrature http://stereo-ssc.nascom.nasa.gov/plans/UlyLocation2006-2014_v1.pdf * Mar 20 - Apr 16 Whole Heliosphere Interval http://ihy2007.org/WHI/targeted_plans.shtml Mar 20-26 JOP 201, Linking Corona to Solar Wind at Ulysses Mar 27-Apr 2 JOP 202, Origin of the Slow Solar Wind Apr 3-9 JOP 203, Coronal hole boundaries *or* JOP 206, Low-latitude coronal holes Apr 10-16 JOP 204, Energetics and dynamics of quiet Sun Targets of opportunity: JOPs 205, 206, 194 * Apr 21 - May 16 SUMER campaign * Oct 6 Messenger - Mercury fly-by 2009: * Sep 29 Messenger - Mercury fly-by 2010: * 2011: * Mar 18 Messenger - Mercury orbital insertion