STEREO Weekly Meeting Minutes for 2009-02-24 (Week 09) ANNOUNCEMENTS ------------- * Behind will switch to IMU #2 on Thursday, Feb 26, for testing. See below for details. 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 08 * Telemetry lock with the Ahead spacecraft was lost twice during the station 25 pass on day 50 (Feb 19), at 14:11 and 14:23 UT. This resulted in a small loss of SSR data. * The station 45 transmitter went offline for 31 minutes during the Behind pass on day 50 (Feb 19), starting at 08:23 UT. A small amount of data was lost during the resweep. * Behind performed an extra SECCHI stepped calibration roll on day 48 (Feb 17) to get better background values for COR1. The COR1 team reports that the roll was successful. The next calibration roll on Behind will be somewhere around day 97 (Apr 7). This will be the perihelion roll, where actual perihelion occurs on day 70 (Mar 11). The next Ahead calibration roll is on day 69 (Mar 10), which is a midpoint roll. * The SECCHI COR1 team noticed a 10 arc second pointing glitch on the Behind spacecraft on Feb 19 at 16:00 UT. APL will look into whether this is another case of a wheel speed avoidance rule firing. Week 09 * The redundant IMU #2 on Behind will be powered up today (Feb 24). If all goes well, the spacecraft will be switched to IMU #2 on Thursday, and then IMU #1 will be powered down. Having both IMUs turned on is known to create some thermal gradiants. This may affect the star tracker, and thus pointing stability to some extent. There was some discussion about contingency plans in case IMU #2 suffers a failure while being used. Week 10 * Kepler is scheduled for launch on Friday, March 6, at 03:48 UT. If the launch is scrubbed, then the DSN schedule for both STEREO spacecraft will be affected. * Daily savings time begins on March 8. Week 11 * A SECCHI stepped calibration roll will be carried out on Ahead on day 69 (Mar 10), starting at 01:20 UT. This is the midpoint roll. * A momentum dump is scheduled for Behind on day 68 (Mar 9) at 20:00 UT. PLASTIC reports that they've been seeing their rates go up during momentum dumps, particularly on Behind. They plan to turn off their entrance system earlier than normal, via time-tagged command rather than signal from the spacecraft, to see if it makes a difference. SWAVES also reports that they see a strong effect from momentum dumps that is not yet understood. Week 12 * The Herschel sounding rocket is currently scheduled to be launched on Mar 20. Other * The testing of the 180 degree roll maneuvers requested by the SECCHI HI team is almost complete, and the rolls will be scheduled soon. * IMPACT has raised a concern that they do not wish the rolls to proceed if there is a large active region on the disk which might produce energetic particles that could be seen by either STEREO spacecraft. Such active regions would have to be significantly larger than those seen since 2006, and would be visible for at least several days ahead of time. Solar weather conditions will be monitored to track any suitable regions, and discussed at the weekly meetings. If necessary, the roll maneuvers can be aborted with 1-2 days notice. * Depending on the G&C planned changes being approved, the APL team has been working on implementing those changes during the last week of April. This involves putting the spacecraft into EA mode, requiring that the instruments be turned off. It was pointed out that this coincided with the SOHO/STEREO workshop in Bournemouth, and that many instrument team members were also planning on attending the EGU meeting the week before. Therefore, it would be better if this activity were postponed until the first full week of May. * SWAVES submitted an IES describing their planned memory load, which they would like to carry out next week. SWAVES and APL will work out the schedule for this offline. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 09: M Feb 23 (054) T Feb 24 (055) Behind: Power on IMU2 W Feb 25 (056) T Feb 26 (057) Behind: Switch to IMU2 F Feb 27 (058) Behind: Power off IMU1 JOP 216: Oscillations in Polar Plumes S Feb 28 (059) JOP 216: Oscillations in Polar Plumes, SECCHI 2-4 UT S Mar 01 (060) ------------------------------------------------------------------------------- Scheduled activities for Week 10: M Mar 02 (061) T Mar 03 (062) W Mar 04 (063) T Mar 05 (064) F Mar 06 (065) S Mar 07 (066) S Mar 08 (067) ------------------------------------------------------------------------------- Scheduled activities for Week 11: M Mar 09 (068) Behind: Momentum dump, 20 UT T Mar 10 (069) Ahead: SECCHI stepped calibration roll, 01:20 UT W Mar 11 (070) T Mar 12 (071) F Mar 13 (072) S Mar 14 (073) S Mar 15 (074) ------------------------------------------------------------------------------- Scheduled activities for Week 12: M Mar 16 (075) T Mar 17 (076) W Mar 18 (077) T Mar 19 (078) F Mar 20 (079) ICAL 14, Herschel sounding rocket launch (TBC) S Mar 21 (080) S Mar 22 (081) Notes * ICAL14, Herschel sounding rocket launch http://sohowww.nascom.nasa.gov/soc/JOPs/ical014-draft.pdf ------------------------------------------------------------------------------- Upcoming events: 2009: ICAL-001: Mar 2-6, Apr 6-10, May 11-22, Jun 15-19, Jul 13-17, Aug 17-21 SECCHI Stepped calibration rolls Ahead: Mar 10, Jun 9, Sep 2, Nov 24 Behind: Apr 7, Jun 16, Sep 22, Dec 22 * Feb/Mar (TBC) JOP 216, Multi-wavelength Observations of Oscillations in Polar Plumes * Mar 20 (TBC) ICAL14, Herschel sounding rocket launch http://sohowww.nascom.nasa.gov/soc/JOPs/ical014-draft.pdf * Late March Behind: Switch back to IMU1 * Mar 27, Apr 2 JOP 80, EIT shutterless * Apr 15-29 SUMER campaign, JOPS 178,195,207,210,214,215,217,218,219 http://www.mps.mpg.de/services/campaignplanner/planning/campaign-200904/ Contact Davina Innes-Markiewicz for access * Apr 16 SUMI sounding rocket launch http://adsabs.harvard.edu/abs/2008AGUSMSP51B..01A * May 11 Both: Begin 6 hour daily DSN tracks * May 18 Ahead: Switch downlink rate to 360 kbps * Jun 1-Jul 10 Sunrise 5-day balloon flight http://star.mpae.gwdg.de/Sunrise/project/publicat/SPIE_2004.pdf * Jun 8 Behind: Switch downlink rate to 360 kbps * Jul 1 Both: HGA calibration * Jul 22 Total solar eclipse http://eclipse.gsfc.nasa.gov/SEmono/TSE2009/TSE2009.html * Aug 3 Both: Begin 7 hour daily DSN tracks * Aug 10 Ahead: Switch downlink rate to 240 kbps * Aug 31 Behind: Switch downlink rate to 240 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) * Dec 7 Behind: Begin 8 hour daily DSN tracks * Dec 14 Behind: Switch downlink rate to 160 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 8 hour daily DSN tracks * Apr 26 Ahead: Switch downlink rate to 160 kbps * Jul 11 Total solar eclipse http://eclipse.gsfc.nasa.gov/SEmono/TSE2010/TSE2010.html * Jul 14 Both: HGA calibration * 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