STEREO Weekly Meeting Minutes for 2011-02-01 (Week 05) ANNOUNCEMENTS ------------- * None. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 4 * On day 025 (Jan 25), during the DSS 65 support for Ahead, turbo decoder lock was lost intermittently at 0658z and again at 0742z. This resulted in the loss of 13 frames of instrument SSR data. A DR has been requested. * On day 027 (Jan 27), during the DSS 25 support for Ahead, command modulation was nine minutes late beginning at 1527z. All SSR data were recovered. See DR# G111026 for more information. * On day 029 (Jan 29), during the DSS 34 support for Ahead, telemetry lock was nine minutes late at BOT due to sub reflector anomaly at the station. This resulted in the loss of nine minutes of real-time telemetry. All SSR data were recovered. See DR# C107900 for more information. * On day 024 (Jan 24), during the DSS 65 support for Behind, the receiver lost connection to the DCD at 1804z. A redundant receiver was placed on-line and the anomaly was cleared at 1807z. This resulted in the loss of several minutes of instrument SSR data. See DR# M106137 for more information. * On day 025 (Jan 25), during the DSS 55 support for Behind, turbo decoder lock was lost briefly at 1813z. This resulted in the loss of one frame of instrument SSR data. See DR# N107054 for more information. * On day 026 (Jan 26), during the DSS 45 support for Behind, telemetry lock was 38 minutes late at BOT due to corrective maintenance to replace two failed transmitter power supplies at the station. This resulted in the loss of 38 minutes of real time telemetry, command, tracking data and several minutes of instrument SSR data. See DR# C107895 for more information. * On day 027 (Jan 27), during the DSS 26 support for Behind, the DCD failed over to the redundant side at 0000z. Later in the support, another DCD anomaly occurred at 0215z to 0258z. These anomalies resulted in the loss of three hours of instrument SSR data. See DR# N107069 and G111025 for more information. * The STEREO project has been struggling during the month of January with the new DCD system. Unlike some other missions, STEREO does not have a retransmit capability. The SECCHI team asked about some data gaps on Behind during the month, including Jan 19, 20 and other dates. * On day 027 (Jan 27), the 29th momentum dump on Behind was successfully executed at 1900z, which imparted a delta V of 0.067 m/sec. * The average daily SSR playback volume was 5.9 gigabits for Ahead, and 5.0 gigabits for Behind. Week 5 * There have been a lot of track changes during the week, due to maintenance being performed at the Goldstone complex to comply with California air quality standards. * The two STEREO spacecraft will reach 180 degrees separation on Sunday, Feb 6. For the next 8 years, when combined with SDO data, the full solar sphere will be visible. This is also a calibration opportunity for the SECCHI telescopes, because they will be looking through the same material. The period of several months around Feb 6 is useful for triangulation. * The 16th SECCHI stepped calibration roll on Ahead was completed today (Feb 1). This counts as both the midpoint roll, and the roll requested by SECCHI for the 180 degree separation. * Due to work on the station 26 transmitter, the passes using that station, for Ahead on Thursday, Feb 3 and Behind on Friday, Feb 4, will be downlink only. * Because of local weather considerations, the command loads for Week 6 for both spacecraft have been moved to Thursday, Feb 3. * Ahead has a 720 kbps pass on Thursday, Feb 3, using station D43. There are 14 passes during the week, and overall coverage is nominal. * Behind has 720 kbps passes on Tuesday, Feb 1, and on Friday, Feb 4, both using station D63, and twice on Sunday, Feb 6, using stations D63 and D14. There are 14 passes during the week, and overall coverage is 2.2 hours over nominal. Week 6 * The 16th SECCHI stepped calibration roll for Behind is scheduled for Tuesday, Feb 8, starting at 9:45 UT, which is earlier than originally scheduled. This serves as both the midpoint roll, and the roll for 180 degree separation. * The weekly schedule reflecting the recent track changes on Behind is now out. * Ahead has a 720 kbps pass on Wednesday, Feb 9, on station D43. There are 14 passes during the week, and overall coverage is nominal. * The track shedule for Behind was extensively changed. Behind has 720 kbps passes on Saturday, Feb 12, and Sunday, Feb 13, both using station D63. There are 12 passes during the week, and overall coverage is nominal. Week 7 * Ahead has no 720 kbps passes. There are 12 passes during the week with 2.1 hours over baseline coverage. * Behind has a 720 kbps pass using D14 starting Friday Feb 18. There are 12 passes during the week, and overall coverage is nominal. Week 8 * Ahead has 720 passes on Monday (Feb 21) and Thursday (Feb 24) on D43. There are 13 passes during the week, and overall coverage is nominal. * Behind has a 720 pass on Sunday (Feb 27) on D43. There are 15 tracks during the week (some very short), and there are 5.4 hours over baseline coverage. Week 9 * Ahead has 720 kbps passes on Tuesday, Mar 1 (D63), Wednesday, Mar 2 (D14 and D43), Thursday, Mar 3 (D63), Friday, Mar 4 (D43), and Sunday, Mar 6 (D14), for a total of six 70 meter passes. There are 13 passes, and overall coverage is nominal. * Behind has two 720 kbps passes (both D63) on Monday and Tuesday. There are 16 passes, and 4.8 hours over baseline. Week 10 * Daily savings time in U.S. starts Sunday, Mar 13. * The 36th momentum dump on Ahead will be carried out on Tuesday, Mar 8, with ignition at 16:00 UT. * The 30th momentum dump on Behind will be carried out on Thursday, Mar 10, with ignition at 19:45 UT. * A return-to-service track on Ahead will be performed using station 15 on Friday, Mar 11, shadowing a track on station 26. Current plans are to perform the uplink on station 15, but this is still to be confirmed. * Ahead has 720 kbps passes on Monday, Mar 7 (D43), Wednesday, Mar 9 (D14), and Friday, Mar 11 (D63). There are 11 tracks during the week, and overall coverage is nominal. * Behind has 720 kbps passes on Monday, Mar 7 (D43), Wednesday, Mar 9 (D14), Friday, Mar 11 (D14), and Sunday, Mar 13 (D14). There are 14 passes during the week, and overall coverage is nominal. Other * Earlier there was discussion about reducing the RF margin to 2 dB. To assist in this, a new downlink performance product will be available shortly. This will be an additional ancillary data product available through the SDS. * In discussions about station performance, it was pointed out that station 14 is still not using a pointing model. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 05: M Jan 31 (031) T Feb 01 (032) Ahead: SECCHI stepped calibration roll, 13:15 UT Behind: 720 kbps downlink on station 63 W Feb 02 (033) T Feb 03 (034) Ahead: 720 kbps downlink on station 63 Ahead: Downlink only pass on station 26 F Feb 04 (035) Behind: 720 kbps downlink on station 63 Behind: Downlink only pass on station 26 S Feb 05 (036) S Feb 06 (037) STEREO spacecraft at 180 degree separation Behind: 720 kbps downlink on stations 63 and 14 ------------------------------------------------------------------------------- Scheduled activities for Week 06: M Feb 07 (038) T Feb 08 (039) Behind: SECCHI stepped calibration roll, 9:45 UT W Feb 09 (040) Ahead: 720 kbps downlink on station 43 T Feb 10 (041) F Feb 11 (042) S Feb 12 (043) Behind: 720 kbps downlink on station 63 S Feb 13 (044) Behind: 720 kbps downlink on station 63 ------------------------------------------------------------------------------- Scheduled activities for Week 07: M Feb 14 (045) T Feb 15 (046) W Feb 16 (047) T Feb 17 (048) F Feb 18 (049) Behind: 720 kbps downlink on station 14 S Feb 19 (050) S Feb 20 (051) ------------------------------------------------------------------------------- Scheduled activities for Week 08: M Feb 21 (052) Ahead: 720 kbps downlink on station 43 T Feb 22 (053) W Feb 23 (054) T Feb 24 (055) Ahead: 720 kbps downlink on station 43 F Feb 25 (056) S Feb 26 (057) S Feb 27 (058) Behind: 720 kbps downlink on station 43 ------------------------------------------------------------------------------- Scheduled activities for Week 09: M Feb 28 (059) Behind: 720 kbps downlink on station 63 T Mar 01 (060) Ahead: 720 kbps downlink on station 63 Behind: 720 kbps downlink on station 63 W Mar 02 (061) Ahead: 720 kbps downlink on station 14 and 43 T Mar 03 (062) Ahead: 720 kbps downlink on station 63 F Mar 04 (063) Ahead: 720 kbps downlink on station 43 S Mar 05 (064) S Mar 06 (065) Ahead: 720 kbps downlink on station 14 ------------------------------------------------------------------------------- Scheduled activities for Week 10: M Mar 07 (066) Ahead: 720 kbsp downlink on station 43 Behind: 720 kbps downlink on station 43 T Mar 08 (067) Ahead: Momentum dump, 16:00 UT W Mar 09 (068) Ahead: 720 kbsp downlink on station 14 Behind: 720 kbps downlink on station 14 T Mar 10 (069) Behind: Momentum dump, 19:45 UT F Mar 11 (070) Ahead: Return-to-service track on station 15 Ahead: 720 kbsp downlink on station 63 Behind: 720 kbps downlink on station 14 S Mar 12 (071) S Mar 13 (072) Start of daily savings time in US Behind: 720 kbps downlink on station 14 ------------------------------------------------------------------------------- Upcoming events: 2011: * Jun 27 Ahead: Switch downlink rate to 160 kbps * Jun 27 Ahead: End use of 720 kbps on 70 m DSN subnet * Jul 15 Behind: Switch downlink rate to 160 kbps * Jul 15 Behind: End use of 720 kbps on 70 m DSN subnet * Jul 25 Behind: Close approach by comet Elenin * Mar 18 Messenger - Mercury orbital insertion * Jul DAWN - Vesta arrival * Jul 13 Both: HGA calibration 2012: * Jan 11 Both: HGA calibration * Jul DAWN - Vesta departure * Jul 11 Both: HGA calibration * Nov 4 Behind: Switch downlink rate to 120 kbps * Nov 13 Total solar eclipse, south Pacific 2013: * May 3 Ahead: Switch downlink rate to 120 kbps * Dec 12 Ahead: Mercury transit 2014: * Jan 20 Behind: End use of 480 kbps on 70 m DSN subnet * Apr 21 Behind: Resume use of 480 kbps on 70 m DSN subnet * Apr 29 Behind: Mercury transit * Oct 15 Behind: End use of 480 kbps on 70 m DSN subnet 2015: * Feb DAWN - Ceres arrival * Jan 20 - Mar 28 (TBC) Behind: Spacecraft behind Sun * Mar 17 - Jul 14 (TBC) Ahead: Spacecraft behind Sun * Jul 2 Behind: Resume use of 480 kbps on 70 m DSN subnet * Aug 25 - Oct 19 (TBC) Behind: Spacecraft behind Sun * Sep 25 Behind: End use of 480 kbps on 70 m DSN subnet * Jul DAWN - End of nominal mission 2016: * Apr 3 Behind: Resume use of 480 kbps on 70 m DSN subnet 2017: * Jul 11 Ahead: Switch downlink rate to 160 kbps * Jul 22 Behind: Switch downlink rate to 160 kbps 2018: * Mar 5 Ahead: Mercury transit