STEREO Weekly Meeting Minutes for 2011-12-13 (Week 50) ANNOUNCEMENTS ------------- * A sungrazing comet, named Comet Lovejoy (C/2011 W3), is currently being observed by STEREO. It was originally discovered from the ground, but has since passed through the HI2-B field-of-view, and is currently visible in the HI1 telescopes on both spacecraft. It will reach perihelion around 0h UT on Dec 16 (late Thursday evening EST), and may well be the brightest sungrazing comet ever observed from space. Special observations are being planned for SECCHI, as well as instruments on the SOHO, SDO, Hinode, and PROBA satellites. SDO is planning to off-point to observe the comet. Of particular interest is the possibility of detecting the comet at EUV wavelengths, as was done earlier in the year by SDO/AIA. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 49 (Dec 5-11) * On day 340 (Dec 6), the second data flow test was successfully conducted between the ESA reference test station, via the DSN, and the STEREO MOC on AHEAD. Live tests with the New Norcia and Cebreros stations are scheduled for next week (Week 51). * On day 342 (Dec 8), during the DSS-26 support for Ahead, turbo decoder lock was lost briefly at 1904z. This anomaly resulted in the loss of one frame of SSR data. See DR# N107806 for more information. * On day 345 (Dec 11), during the DSS-43 support for Ahead, turbo decoder lock was lost briefly at 0050z and again at 0132z. This anomaly resulted in the loss of six frames of SSR data. A DR has been requested. * On day 341 (Dec 7), MOps permanent macro release 1.1.14 was loaded to C&DH RAM on both spacecraft. This release modified a star tracker contingency macro to collect more diagnostic data during a star tracker reset. * On day 340 (Dec 6), during the DSS-15 support for Behind, turbo decoder lock was lost briefly at 1847z and again at 1908z due to the tracks being spaced too close together, closer than the round-trip light travel time. This anomaly resulted in the loss of 295 frames of SSR data. * On day 342 (Dec 8), during the DSS-63 support for Behind, turbo decoder lock was lost briefly at 1257z and again at 1607z. This anomaly resulted in the loss of three frames of SSR data. See DR# N107807 for more information. * On day 343 (Dec 9), the DSS-55 support for Behind was shortened by one hour to duration of 2.9 hours and the DSS-26 support was shortened by 30 minutes to duration of 4.5 hours to assist the Kepler mission with safe mode recovery. All SSR data were received. * On day 342 (Dec 8), a battery conditioning event was successfully conducted on the BEHIND spacecraft to redistribute the electrolytes within the nickel hydrogen battery cells. * The average daily SSR playback volume was 5.3 gigabits for Ahead, and 4.8 gigabits for Behind. Week 50 (Dec 12-18) * Ahead has 70 meter passes on Monday, Dec 12 (D63 at 720 kbps), Wednesday, Dec 14 (D14 at 720 kbps), Thursday, Dec 15 (D14), Saturday, Dec 17 (D63), and Sunday, Dec 18 (D14, D43 at 720 kbps). There are 11 passes during the week, and overall coverage is nominal. * Behind has 70 meter passes on Monday, Dec 12 (D63), Friday, Dec 16 (D43), and Sunday, Dec 18 (D63). There are 13 passes during the week, and overall coverage is nominal. The station 25 pass on Dec 15 will be carried out at 240 kbps. Week 51 (Dec 19-25) * Four ESA test tracks will be scheduled during the week, with the following schedule: Dec 20, 00:45 UT, Ahead, New Norcia, 2 hours Dec 20, 19:10 UT, Behind, Cebreros, 35 minutes (shadow track) Dec 21, 03:30 UT, Behind, New Norcia, 2 hours Dec 21, 05:35 UT, Ahead, Cebreros, 35 minutes The Cebreros track on Dec 20 is a shadow track overlapping the station 15 track. The other tracks are all followed by 70 meter tracks, and the pointers will be moved back at the end of these test tracks. SECCHI should not take the ESA test tracks into account when planning their telemetry usage. The ESA stations currently do not have frequency authorization for STEREO, so the tracks will be downlink only. The stations appear in the DSN schedule as station 32 for New Norcia, and station 62 for Cebreros. * Momentum dumps are scheduled during the week. These are a bit early, but have been moved forward because of the subsequent holidays. * The 37th momentum dump on Behind is scheduled for Monday, Dec 19, with ignition at 16:00 UT. * The 43rd momentum dump on Ahead is scheduled for Tuesday, Dec 20, with ignition at 17:00 UT. * December 25 is Christmas day. Monday, Dec 26, is a holiday at APL. * Ahead has 70 meter passes every day during the week. The station 14 pass on Wednesday, Dec 21 will be carried out at 720 kbps. There are 9 passes during the week, and overall coverage is nominal. * Behind has 70 meter passes on Monday, Dec 19 (D63), Tuesday, Dec 20 (D63), Wednesday, Dec 21 (D63), Friday, Dec 23 (D43 at 720 kbps), Saturday, Dec 24 (D14 at 720 kbps), and Sunday, Dec 25 (D63). There are 11 passes during the week, and overall coverage is nominal. The station 15 pass on Dec 21 will be carried out at 240 kbps. Week 52 (Dec 26 - Jan 1) * Ahead has 70 meter passes on Thursday, Dec 29, and Sunday, Jan 1, both using station 14. There are 15 passes during the week, and overall coverage is nominal. The station 34 pass on Saturday, and the station 54 pass on Sunday, will be carried out at 240 kbps. * Behind has a 70 meter pass on Tuesday, Dec 27, at 720 kbps using station 63. There are 11 passes during the week, and overall coverage is nominal. The station 34 pass early on Sunday, Jan 1, will be carried out at 240 kbps. Week 1 (Jan 2-8) * Monday, Jan 2, is a holiday at APL. * Tracks using the ESA New Norcia station are scheduled for Jan 5 on Ahead, and Jan 8 on Behind. These will appear on the schedule as station 32. These tracks have been moved to an earlier start time. * Ahead has 70 meter passes on Monday, Jan 2, and Saturday, Jan 7, both using station 14. There are 14 passes during the week, and overall coverage is nominal. The station 26 pass on Thursday, Jan 5, and the station 45 pass on Sunday, Jan 8, will be carried out at 240 kbps. * Behind has a 70 meter pass on Saturday, Jan 7, using station 43 at 720 kbps. There are 12 passes during the week, and overall coverage is nominal. The station 15 pass on Wednesday will be carried out at 240 kbps. Week 2 (Jan 9-15) * The 20th SECCHI stepped calibration roll for Ahead is scheduled for Tuesday, Jan 10, starting at 02:40 UT. This will be the midpoint roll. System momentum is expected to be around 1 N-m-s. * HGA calibration rolls are scheduled on Behind on Tuesday, Jan 10, starting at 16:00 UT, and on Ahead on Thursday, Jan 12, starting at 19:00 UT. This represents a change in date and start time for the Ahead spacecraft. Each spacecraft will be rotated by +/- 1/2 degree, and the maneuver will last about one hour. * A 2 hour pass for Behind is scheduled on the ESA New Norcia D32 station on Saturday, Jan 14, starting at 03:20 UT. * Ahead has a 70 meter pass on Thursday, Jan 12, using station 43. There are 11 passes during the week, and overall coverage is nominal. The station 34 pass on Saturday, Jan 14, will be carried out at 240 kbps. * Behind has 12 passes during the week, and overall coverage is nominal. There are no 70 meter or high elevation passes during the week. Week 3 (Jan 16-22) * A 2.25 hour pass for Behind is scheduled on the ESA New Norcia D32 station on Thursday, Jan 19, starting at 06:30 UT. * Ahead has 70 meter passes on Monday, Jan 16 (D63), Tuesday, Jan 17 (D43), Thursday, Jan 19 (D14, D43 at 720 kbps), and Saturday, Jan 21 (D43 twice, one at 720 kbps). There are 10 passes during the week, and overall coverage is nominal. * Behind has 70 meter passes on Monday, Jan 16, Tuesday, Jan 17, Thursday, Jan 19, Saturday, Jan 21, and Sunday, Jan 22, all using station 63. There are 15 passes during the week, and overall coverage is nominal. The station 34 pass on Monday will be carried out at 240 kbps. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 50: M Dec 12 (346) Ahead: 70 meter downlink on station 63 Behind: 70 meter downlink on station 63 T Dec 13 (347) W Dec 14 (348) Ahead: 70 meter downlink on station 14 T Dec 15 (349) Ahead: 70 meter downlink on station 14 F Dec 16 (350) Behind: 70 meter downlink on station 43 S Dec 17 (351) Ahead: 70 meter downlink on station 63 S Dec 18 (352) Ahead: 70 meter downlink on stations 14 and 43 Behind: 70 meter downlink on station 63 ------------------------------------------------------------------------------- Scheduled activities for Week 51: M Dec 19 (353) Behind: Momentum dump, 16:00 UT Ahead: 70 meter downlink on station 63 Behind: 70 meter downlink on station 63 T Dec 20 (354) Ahead: Momentum dump, 17:00 UT Ahead: 70 meter downlink on station 14 Behind: 70 meter downlink on station 63 Ahead: Test track with New Norcia (D32) at 00:45 UT Behind: Test track with Cebreros (D62) at 19:10 UT W Dec 21 (355) Ahead: 70 meter downlink on station 14 Behind: 70 meter downlink on station 63 Ahead: Test track with Cebreros (D62) at 05:35 UT Behind: Test track with New Norcia (D32) at 03:30 UT T Dec 22 (356) Ahead: 70 meter downlink on station 14 F Dec 23 (357) Ahead: 70 meter downlink on station 63 Behind: 70 meter downlink on station 43 S Dec 24 (358) Ahead: 70 meter downlink on station 14 Behind: 70 meter downlink on station 14 S Dec 25 (359) Ahead: 70 meter downlink on station 14 Behind: 70 meter downlink on station 63 ------------------------------------------------------------------------------- Scheduled activities for Week 52: M Dec 26 (360) T Dec 27 (361) Behind: 70 meter downlink on station 63 W Dec 28 (362) T Dec 29 (363) Ahead: 70 meter downlink on station 14 F Dec 30 (364) S Dec 31 (365) S Jan 01 (001) Ahead: 70 meter downlink on station 14 ------------------------------------------------------------------------------- Scheduled activities for Week 01: M Jan 02 (002) Ahead: 70 meter downlink on station 14 T Jan 03 (003) W Jan 04 (004) T Jan 05 (005) F Jan 06 (006) S Jan 07 (007) Ahead: 70 meter downlink on station 14 Behind: 70 meter downlink on station 43 S Jan 08 (008) ------------------------------------------------------------------------------- Scheduled activities for Week 02: M Jan 09 (009) T Jan 10 (010) Ahead: SECCHI stepped calibration roll, 02:40 UT Behind: HGA calibration, 16:00 W Jan 11 (011) T Jan 12 (012) Ahead: HGA calibration, 17:00 Ahead: 70 meter downlink on station 43 F Jan 13 (013) S Jan 14 (014) S Jan 15 (015) ------------------------------------------------------------------------------- Scheduled activities for Week 03: M Jan 16 (016) Ahead: 70 meter downlink on station 63 Behind: 70 meter downlink on station 63 T Jan 17 (017) Ahead: 70 meter downlink on station 43 Behind: 70 meter downlink on station 63 W Jan 18 (018) T Jan 19 (019) Ahead: 70 meter downlink on stations 14 and 43 Behind: 70 meter downlink on station 63 F Jan 20 (020) S Jan 21 (021) Ahead: 70 meter downlink on station 43 (twice) Behind: 70 meter downlink on station 63 S Jan 22 (022) Behind: 70 meter downlink on station 63 ------------------------------------------------------------------------------- Upcoming events: 2012: * 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