STEREO Weekly Meeting Minutes for 2008-12-09 (Week 50) ANNOUNCEMENTS ------------- * The DNS/DHCP servers at APL will be undergoing maintenance on Dec 13, between 12-19 UT. 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 49 * The station 65 transmitter is currently limited to 5 kW of uplink power, which is not quite enough to close the uplink loop at the present distance of the STEREO spacecraft. This affected the Ahead tracks for days 336, 339, and 341 (Dec 1, 4, 6), and the Behind track on day 341 (Dec 6). These tracks had no commanding or tracking. DSN is still working on the problem. This is an issue for tomorrow (Dec 10) on Behind. * A number of recent tracks have had invalid range tracking data, 11 tracks on Ahead since Nov 22, and 12 tracks on Behind since Nov 26. This problem has been tracked to a software anomaly, and a patch is being deployed. In the meantime, JPL has reprocessed the affected tracks, and a workaround has been delivered to the antenna network. * The aphelion SECCHI stepped calibration roll on Ahead was carried out on day 337 (Dec 2). The actual aphelion will be on Monday (Dec 15) at 05:43 UT. * On day 335 (Nov 3), station 55 lost command bind at 17:48 during the Behind pass. This resulted in a loss of 7 minutes of commanding and realtime data. * The average daily downlink was 7.0 gigabits on Ahead and 6.7 gigabits on Behind. Week 50 * The DNS/DHCP servers at APL will be undergoing maintenance on Saturday, Dec 13. See the announcement above for details. * The station 14 transmitter went red yesterday (Dec 8). The station was used this morning (Dec 9) for downlink. However, the SSR pointers were not reset. Unless another track for commanding can be arranged, some data will be lost when the instrument buffers (mainly SECCHI) are filled. * The G&C team reports some unusual gyro data in Behind yesterday (Dec 8). The instrument teams should examine their data to see if anything unusual is evident. * The instrument teams should be aware that no uplink will be available on Behind tomorrow (Dec 10) because of the station 65 transmitter limitation discussed above. Week 51 * Ahead will reach aphelion at 05:43 UT on Monday, day 350 (Dec 15). * The 18th momentum dump is scheduled for Ahead on day 352 (Dec 17) at 13:00 UT. * The midpoint stepped calibration roll on Behind is scheduled for Tuesday, day 351 (Dec 16) at 03:50 UT. Week 52 * A quiet week is scheduled because of the Christmas holiday on Thursday. APL will be closed for the holidays on both Thursday and Friday, so the instrument teams should arrange to send any necessary commands up before then. Other * The STEREO Science Center experienced some disk problems over the weekend which prevented them from ingesting telemetry and other data files from APL. They have now switched over to a backup disk system, and are now catching up on the backload of data. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 50: M Dec 08 (343) T Dec 09 (344) W Dec 10 (345) T Dec 11 (346) F Dec 12 (347) S Dec 13 (348) DNS/DHCP maintenance at APL S Dec 14 (349) ------------------------------------------------------------------------------- Scheduled activities for Week 51: M Dec 15 (350) T Dec 16 (351) Behind: SECCHI stepped calibration roll, 03:50 W Dec 17 (352) Ahead: Momentum dump, 13:00 UT T Dec 18 (353) F Dec 19 (354) S Dec 20 (355) S Dec 21 (356) ------------------------------------------------------------------------------- Scheduled activities for Week 52: M Dec 22 (357) T Dec 23 (358) W Dec 24 (359) T Dec 25 (360) F Dec 26 (361) S Dec 27 (362) S Dec 28 (363) ------------------------------------------------------------------------------- Upcoming events: 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 * Jan 23 Herschel sounding rocket launch * 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 1-Jul 5 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 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 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 25 Behind at L5 Lagrange point * Nov 1-Dec 15 SUMER campaign (TBC) * Dec Behind: Switch downlink rate to 160 kbps