STEREO Weekly Meeting Minutes for 2009-12-22 (Week 52) ANNOUNCEMENTS ------------- * There is a continuing problem with intermittent loss of Turbo lock on station 55. See below for details. * SECCHI reminded the MOC that they will require a pointer reset on Dec 27. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 51 * The average daily SSR downlink was 6.3 gigabits on Ahead, and 4.7 gigabits on Behind. Now that Behind is at 240 kbps, the MOC is no longer guaranteeing an average of 5 gigabits/day of downlink. * Intermittent problems with loss of Turbo lock persisted on station 55, and affected the Behind passes on days 349 and 350 (Dec 15,16), resulting in the loss of a number of telemetry frames, affecting all instruments. This problem has been traced to internal interference when the transmitter is radiating. Actual commanding is not necessary to cause the problem. DSN is checking the filter. They are also checking whether a lower uplink power might mitigate the problem. These tests will be carried out during the station maintenance period. Other missions are also affected, including Kepler and Cassini. The problem may trace back to the fix for a previous problem involving the exciter. It was remarked that a DR should be opened for any events impacting data receipt. * Station 63 is currently about 0.3 dB down when supporting STEREO. * The station 25 transmitter went offline during the Behind pass on day 353 (Dec 19). This resulted in one SWAVES command not being uplinked. It was subsequently uplinked on day 355 (Dec 21). Also, 1518 SSR telemetry frames were lost. * The station 25 transmitter went offline again during the Behind pass on day 354 (Dec 20) at 19:54 UT, and then again at 01:08 UT. This resulted in the loss of 1188 telemetry frames. Week 52 * Station 65 lost telemetry during the Ahead pass on day 355 (Dec 21) due to snow in Madrid. Telemetry was lost starting at 06:17 UT, and continued through the rest of the track. * The 20th momentum dump was successfully carried out on Behind today (Dec 22) at 16:00 UT. * IMPACT asked about their SSR partition filling on Behind. This apparently occured 7 minutes before the end-of-track, and the pointers should have been reset at the end-of-track, minimizing any data loss. * The Thursday before Christmas (Dec 24) is a half-day holiday at APL. Week 53 * Attended passes will be on Dec 30. * A 70 meter track is scheduled on Behind on day 363 (Dec 29) using station 63. This pass will be carried out at 720 kbps. * New Years Eve (Dec 31) is a half-day holiday at APL. Week 1 * HGA calibrations will be carried out on both spacecraft on Jan 6. The start times will be Ahead: 14:00, Behind: 16:00 UT. * The 12th SECCHI stepped calibration roll will be carried out on Behind on Jan 5, starting at 12:15 UT. * A 2.5 hour PIT test track will be carried out on Behind using station 15 on Jan 7, between 01:30 and 03:55 UT. There will be no SSR playback and no instrument commanding during this track. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 52: M Dec 21 (355) T Dec 22 (356) Behind: Momentum dump, 16:00 UT W Dec 23 (357) T Dec 24 (358) F Dec 25 (359) Christmas S Dec 26 (360) S Dec 27 (361) ------------------------------------------------------------------------------- Scheduled activities for Week 53: M Dec 28 (362) T Dec 29 (363) Behind: 720 kbps downlink on station 63 W Dec 30 (364) T Dec 31 (365) F Jan 01 (001) New Year S Jan 02 (002) S Jan 03 (003) ------------------------------------------------------------------------------- Scheduled activities for Week 01: M Jan 04 (004) T Jan 05 (005) Behind: SECCHI stepped calibration roll, 12:15 W Jan 06 (006) HGA calibration, Ahead 14:00 UT, Behind 16:00 UT T Jan 07 (007) Behind: PIT test track, station 15, 01:30-03:55 F Jan 08 (008) S Jan 09 (009) S Jan 10 (010) ------------------------------------------------------------------------------- Upcoming events: 2009: ICAL-001: Dec 14-18 * Ongoing JOP 222, Origin of SEPS, Target of opportunity 2010: ICAL-001: Jan 11-15, Feb 15-19, Mar 15-19, Apr 12-16, May 3-7 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 * Jan 7,15 EIT shutterless (TBC) * Spring (TBD) SUMI sounding rocket launch http://adsabs.harvard.edu/abs/2008AGUSMSP51B..01A * Apr 8,15 EIT shutterless (TBC) * Apr 19 Ahead: Begin 7 hour daily DSN tracks * Apr 26 Ahead: Switch downlink rate to 240 kbps * Jul 8,15 EIT shutterless (TBC) * Jul 11 Total solar eclipse http://eclipse.gsfc.nasa.gov/SEmono/TSE2010/TSE2010.html * Jul 14 Both: HGA calibration * Sep 7 Both: Begin 8 hour daily DSN tracks * Sep 13 Both: Switch downlink rate to 160 kbps * Nov 15 Behind: Switch downlink rate to 120 kbps 2011: * Jan 12 Both: HGA calibration * Feb 6 STEREO spacecraft at 180 degree separation * 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 * Nov 13 Total solar eclipse, south Pacific 2013: * Dec 12 Ahead: Possible Mercury transit (TBC) 2014: * Apr 29 Behind: Possible Mercury transit (TBC) 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