STEREO Weekly Meeting Minutes for 2008-06-24 (Week 26) ANNOUNCEMENTS ------------- * None. 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 25 * The 14th momentum dump on Ahead was carried out on day 170 (Jun 18) at 14:30 UT. * IMU and ST alignments were uploaded to G&C RAM on both spacecraft on day 170 (Jun 18). * The average daily downlink volume was 6.9 gigabits on Ahead, and 7.9 gigabits on Behind. * On day 170 (Jun 18), during the Behind pass on station 45, the transmitter went offline at 09:22 UT. A small amount of SSR data was lost. Commanding and tracking data were unavailable for 98 minutes. Week 26 * A SECCHI stepped calibration roll is scheduled for Behind tomorrow (Jun 25) at 14:20 UT. This is a make-up for the previous calibration roll, which had some pointing problems. Changes were made to the G&C telemetry schedule to reduce the volume, so that G&C data for the whole event can be collected. Testing was completed today on the HIL. The new schedule will be loaded tonight on Behind. * A SECCHI stepped calibration roll is scheduled for Ahead on day 178 (Jun 26) at 08:55 UT. This is the perihelion roll. Perihelion is actually at 21:55 UT on the following day. The updated schedule for this event will be uploaded tomorrow morning (Jun 25). Week 27 * SECCHI GT-driven off-points on both spacecraft are scheduled for Monday, day 182 (Jun 30), at 16:15 for Ahead, and 12:15 for Behind. These off-points are used to flat field the EUVI telescope. The total amount of off-point will be no more than 2 arc minutes. Week 28 * The 8th HGA calibrations are scheduled on both spacecraft on day 191 (Jul 9), at 14:00 UT for Ahead, and 17:00 UT for Behind. HGA roll scripts in case of star tracker loss will also be tested. The tests are split between the spacecraft, and will roll by +/- 0.5 on Ahead, and +/- 1.0 degrees on Behind. Week 29 * The 10th momentum dump will be performed on Behind on day 199 (Jul 17) at 19:45 UT. Other * The SSC and instrument teams had a telecon last week about telemetry rates during the extended mission. The next telecon is scheduled for July 8, and will include MOps. One telemetry reduction scheme that the instrument teams are very interested in is to reduce the amount of realtime telemetry, so that more bandwidth can be devoted to downloading the SSR. The instrument teams would like to normally only send down specific APIDs in realtime. During special operations, however, they would like to send down everything that's currently included in the realtime telemetry. Therefore, a total of six downlink scenarios are proposed: one with each instrument getting their minimal telemetry, four where one instrument gets its full allocation, and one where all the instruments get their full allocations. The instrument teams ask whether such a scheme is feasible. * The PLASTIC team reports that a change in their telemetry rate will require an onboard software modification to the DPU. * A total solar eclipse will occur on August 1st. * It is expected that there will be a quarterly review for STEREO in the near future. * Steve Odendahl reminded the instrument teams to send information about SEUs that have been seen since launch. It was decided that these statistics should only include SEUs which have an impact on operations, such as causing a system reboot, and not SEUs which are automatically corrected by the onboard systems. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 26: M Jun 23 (175) T Jun 24 (176) W Jun 25 (177) Behind: SECCHI stepped calibration roll, 14:20 T Jun 26 (178) Ahead: SECCHI stepped calibration roll, 08:55 F Jun 27 (179) S Jun 28 (180) S Jun 29 (181) Notes: * Jun 20-30, SUMER observing ------------------------------------------------------------------------------- Scheduled activities for Week 27: M Jun 30 (182) SECCHI GT-driven off-point, Ahead 16:15, Behind 12:15 T Jul 01 (183) W Jul 02 (184) T Jul 03 (185) F Jul 04 (186) S Jul 05 (187) S Jul 06 (188) Notes: * Jun 20-30, SUMER observing ------------------------------------------------------------------------------- Scheduled activities for Week 28: M Jul 07 (189) T Jul 08 (190) W Jul 09 (191) HGA calibrations, Ahead: 14:00, Behind: 17:00 T Jul 10 (192) F Jul 11 (193) S Jul 12 (194) S Jul 13 (195) ------------------------------------------------------------------------------- Scheduled activities for Week 29: M Jul 14 (196) T Jul 15 (197) W Jul 16 (198) T Jul 17 (199) Behind: momentum dump, 19:45 F Jul 18 (200) S Jul 19 (201) S Jul 20 (202) ------------------------------------------------------------------------------- Upcoming events: 2008: SECCHI Stepped calibration rolls Ahead: Sep 23, Dec 16 Behind: Aug 26, Dec 2 ICAL-001: Jun 30-Jul 3, Aug 4-8, Sep 1-5, Oct 6-10, Nov 3-7, Dec 1-5 * Jul 23,30 EIT shutterless * Aug 1 Total solar eclipse, 9:20-11:20 UT http://eclipse.gsfc.nasa.gov/SEmono/TSE2008/TSE2008.html * Aug 4 Begin 5 hour daily DSN tracks * Aug 11 Ahead: Switch downlink rate to 480 kbps * Sep 8 Behind: Switch downlink rate to 480 kbps * Oct 6 Messenger - Mercury fly-by * Nov 1-Dec 15 SUMER campaign