STEREO Weekly Meeting Minutes for 2008-11-18 (Week 47) ANNOUNCEMENTS ------------- * The APL network outage originally scheduled for November is now anticipated in January. * The DNS/DHCP servers at APL will be undergoing maintenance on Dec 13. Computers should continue to be accessible by IP address, but access by name may not be available while the maintenance is going on. The duration of this event is expected to be 7 hours, but the start time is not yet known. 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 46 * An anomaly with the station 55 ranging equipment occurred during the Ahead track on day 318 (Nov 13). This resulted in the los of 4 hours of ranging data. * Several SSR telemetry frames were lost during the Ahead pass on station 45 on day 318 (Nov 13). This affected all instruments for several seconds. * Heavy rain at station 45 during the Behind pass on day 319 caused a loss of lock, resulting in several minutes of SSR data. * The average daily downlink was 6.6 gigabits on Ahead, and 7.4 gigabits on Behind. Week 47 * A power glitch occurred at station 25 yesterday (Nov 17) at 13:47 in the middle of the Ahead pass. The MOps team is still assessing the amount of data loss. * DSN reports that the exciter on station 25 is currently red, and suggests that upcoming passes using this station be rescheduled to use another station at the same complex. Week 48 * The 12th momentum dump is scheduled for Behind on Monday, day 329 (Nov 24), with ignition at 18:30 UT. * Thanksgiving is on November 27. Week 49 * The aphelion SECCHI stepped calibration roll on Ahead is scheduled for 14:50 UT on Dec 2. The time has been changed to reflect a changed DSN schedule. Actual aphelion is on day 350 (Dec 15), but the roll maneuver has been moved earlier for better momentum wheel speeds. The following track starts at 18:20 UT. Other * The DNS/DHCP server at APL will be undergoing maintenance on Saturday, Dec 13. See the announcement above for more details. * A question was raised about the use of 70 meter dishes. At one point it was discussed that STEREO could still use a 720 kbps telemetry rate on these dishes. However, it was decided to not make use of this capability, because of the risk that the pass may need to be switched to a smaller antenna. * A SECCHI stepped calibration roll on Behind is planned for Dec 16. This roll was also moved because of momentum wheel speed considerations. * A momentum dump on Ahead is tentatively scheduled around day 352 (Dec 17). COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 47: M Nov 17 (322) T Nov 18 (323) W Nov 19 (324) T Nov 20 (325) F Nov 21 (326) S Nov 22 (327) S Nov 23 (328) ------------------------------------------------------------------------------- Scheduled activities for Week 48: M Nov 24 (329) Behind: Momentum dump, 18:30 UT T Nov 25 (330) W Nov 26 (331) T Nov 27 (332) Thanksgiving F Nov 28 (333) S Nov 29 (334) S Nov 30 (335) ------------------------------------------------------------------------------- Scheduled activities for Week 49: M Dec 01 (336) T Dec 02 (337) Ahead: SECCHI calibration roll, 14:50 UT W Dec 03 (338) T Dec 04 (339) F Dec 05 (340) S Dec 06 (341) S Dec 07 (342) ------------------------------------------------------------------------------- Upcoming events: 2008: SECCHI Stepped calibration rolls Ahead: Dec 2 Behind: Dec 16 ICAL-001: Dec 1-5 2009: ICAL-001: Jan 5-9, Jan 26-30, Mar 2-6, Apr 6-10, May 11-22 SECCHI Stepped calibration rolls Ahead: Mar 10, Jun 9, Sep 2, Nov 24 Behind: Mar 10, Jun 16, Sep 22, Dec 22 * Jan TBD Planned network outage at APL * Jan 15,22 JOP 80, EIT shutterless * Feb DAWN - Mars fly-by * Apr 16,23 JOP 80, EIT shutterless * Apr Two week SUMER campaign (TBC) * May 18 Ahead: Switch downlink rate to 360 kbps * Jun 8 Behind: Switch downlink rate to 360 kbps * Jul 22 Total solar eclipse http://eclipse.gsfc.nasa.gov/SEmono/TSE2009/TSE2009.html * Aug 4 Both: Increase track duration from 4 to 5 hours * Aug 10 Ahead: Switch downlink rate to 160 kbps * Aug 31 Behind: Switch downlink rate to 160 kbps * Sep 10 Ahead at L4 Lagrange point * Sep 29 Messenger - Mercury fly-by * Oct 25 Behind at L5 Lagrange point * Nov 1-Dec 15 SUMER campaign (TBC)