STEREO Weekly Meeting Minutes for 2010-11-23 (Week 47) ANNOUNCEMENTS ------------- * The STEREO Science Center will be moving from building 26 at Goddard to building 21. The current anticipated date of the move is now Nov 29, with the computers being turned off starting the evening of Nov. 28. See below for details. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * All subsystems on both spacecraft are nominal. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 46 * On day 322 (Nov 18), during the DSS 54 support for Ahead, turbo decoder lock was lost intermittently at 0747z through 0810z. This resulted in the loss of four frames of instrument SSR data. See DR# N106757 for more information. * On day 323 (Nov 19), during the DSS 14 support for Ahead, the antenna brakes were set at 1300z. The brakes were released and tracking resumed, however the problem recurred at 1323z. DSS 14 was declared red for the remainder of the support. This resulted in the loss of 104 minutes of real-time data, and nine hours of S/C housekeeping data. All instrument SSR data was recovered. See DR# G110771 for more information. * On day 324 (Nov 20), the scheduled DSS 45 support for Ahead at 0100z was canceled as DSS 45 was not ready to support. A 3.6 hour DSS 63 support was added with a BOT of 324-0450z. As there was no track prior to this newly added track, a blind acquisition was conducted which configured the S/C for a 720 kbps downlink. SSR pointers were moved to recover the lost data from the previous DSS 14 anomaly and missed DSS 45 support. While all instruments SSR data was recovered, eight hours of S/C housekeeping data was lost. * A question was raised about the data loss log. The logs do not properly handle the situation when the loss goes over day boundaries. One can see what period was lost by looking at the converted spacecraft housekeeping. * On day 325 (Nov 21), the DSS 54 support for Ahead did not occur as the antenna was declared red due to a failed down converter. SSR pointers were moved on the next support with DSS 26 to recover the lost data from this outage. All SSR data was recovered. See DR# M106055 for more information. * On day 324 (Nov 20), the SECCHI instrument on Ahead reset at 06:31:47z. The SECCHI team reconfigured the instrument to operational mode at 324-1530z. This was the 18th reset of SECCHI on the Ahead spacecraft. Earlier, a change was implemented to address a known erratum for the electronics in the hope that this would fix the problem with watchdog resets; however, this appears to not have had any effect. * On day 319 (Nov 15), during the DSS 55 support for Behind, turbo decoder lock was lost intermittently at 1848z through 1852z. This resulted in the loss of several minutes of instrument SSR data. See DR# N106764 for more information. * On day 322 (Nov 18), the in-situ instrument partitions on Behind filled at 0732z due to insufficient track time on day 321. The autonomy rule to free SSR space fired at 1556z. The final result was the loss of two to eight hours of instrument SSR data. * On day 322 (Nov 18), during the DSS 54 support for Behind, turbo decoder lock was lost intermittently at 1621z through 1740z. This resulted in the loss of three frames of instrument SSR data. See DR# N106763 for more information. * On day 324 (Nov 20), the scheduled DSS 45 support for Behind at 0515z was canceled as DSS 45 was not ready to support. A 3.6 hour DSS 55 support was added with a BOT of 324-1530z. All SSR data were recovered. * On day 325 (Nov 21), the scheduled DSS 54 support for Behind at 1610z was canceled due to an ongoing power upgrade at the Goldstone DSN complex. This resulted in the loss of two to six hours of instrument SSR data. * On day 325 (Nov 21), during the DSS 14 support for Behind, turbo decoder lock was lost intermittently at 2008z. This resulted in the loss of several minutes of instrument SSR data. * The average daily SSR playback was 4.5 gigabits for Ahead, and 4.4 gigabits for Behind. * There were four command aborts during the week using the Madrid station, which is unusual. Week 47 * There was no ranging support during the station 14 pass for Ahead yesterday (Nov 22) due to a problem with the uplink ranging assembly. * The signal was dropped during the station 14 pass for Ahead yesterday (Nov 22) due to low signal strength. This resulted in the loss of about one hour of data. The pass started at 26 degrees elevation. When the elevation reached 45 degrees, the signal strength suddenly shot up. There was some discussion whether this may be due to the lack of an updated pointing model needed for precision mode pointing. The new pointing model has now been installed. Similar problems were seen during the station 63 pass on Friday night, after the blind acquisition, though the signal was never lost. This may be due to a misconfiguration. * IMPACT performed LET commanding on both spacecraft yesterday (Nov 22). * Thursday, Nov 25 is Thanksgiving in US. Friday, Nov 26 is also a holiday at APL. The MOC will be operating unattended both days. * Ahead has 720 kbps passes on Monday, Nov 22, using station 14, Tuesday, Nov 23, using station 63, and Sunday, Nov 28, using station 14. There are 14 tracks during the week, and overall coverage is nominal. * Behind has 720 kbps passes on Monday, Nov 22, using station 63, and Friday, Nov 26, using station 14. There are 14 tracks during the week, and overall coverage is nominal. * There is currently a problem with station 15. However, the problem is expected to be resolved by 4 P.M. before the Behind pass tonight (Nov 23), where the SOA is 22:55 UT. Week 48 * The 34th momentum dump on Ahead will be carried out Thursday, Dec 2, with ignition at 15:00 UT. * SWAVES asked if there was a burn schedule that they could compare with the radio signatures that they observe. This is in support of the Solar Probe project, where the suggestion has been made to use thrusters instead of a momentum wheel. The fuel is modeled as coming out in neutral form, but some portion of it would have to be ionized to appear in the SWAVES data. PLASTIC is also interested in seeing these data. * There will be a test track using station 25 on Behind on Dec 1, shadowing the track on station 26. * Ahead has 720 kbps passes on Monday, Nov 29, Wednesday, Dec 1, Thursday, Dec 2, and Saturday, Dec 4. The Monday pass uses station 14; the rest use station 63. There are 14 tracks during the week, and overall coverage is nominal. * Behind has 720 kbps passes on Friday Dec. 3 and Sunday, Dec 5, using station 63. There are 13 tracks during the week, and overall coverage is 2 hours below nominal. Week 49 * Ahead has a 720 kbps pass on Tuesday, Dec 7, using station 43. There are 14 passes during the week, and overall coverage is nominal. * Behind has a 720 kbps pass on Wednesday, Dec 8, using station 63. There are 11 passes during the week, and overall coverage is 1.8 hours above nominal. * There is a 32 hour gap between Behind passes Thursday to Friday (Dec 9-10). This will be close for the in situ instruments. Because of the 70 meter pass on Dec 8, the buffers should start out empty. Week 50 * The 28th momentum dump on Behind will be performed on Dec 15, with ignition at 17:30 UT. * Ahead has 720 kbps passes on Monday, Dec 13, using station 43, on Thursday, Dec 16, using station 43, and on Saturday, Dec 18, using station 63. There are 13 passes during the week, and overall coverage is nominal. * Behind has a 720 kbps pass on Wednesday, Dec 15, using station 63. There are 11 passes during the week, and overall coverage is nominal. Week 51 * Christmas is on Saturday, Dec 25. Friday, Dec 24 is a holiday at APL. * Ahead has 720 kbps passes on Monday Dec 20 (D43), Wednesday, Dec 22 (D43), and Saturday, Dec 25 (D43). There are 14 passes during the week, and overall coverage is nominal. * Behind has 720 kbps passes on Monday, Dec 20 (D63), Tuesday, Dec 21 (D63), Thursday, Dec 23 (D14), and Saturday, Dec 25 (D43). There are 10 passes during the week, and overall coverage is 3.2 hours below nominal. * There is only a short 3.8 hour track for Behind on Wednesday, Dec 22. The in situ instruments may come close to filling the SSR buffers. * The DSN schedule should accommodate the Christmas schedules for the stations. Week 52 * New Year's Day is on Saturday, Jan 1. Friday, Dec 31 is a holiday at APL. * Ahead has a 720 kbps pass on Wednesday, Dec 29 using station 43. There are 14 passes during the week, and overall coverage is nominal. * Behind has a 720 kbps pass on Friday, Dec 31, using station 43. There are 12 passes during the week, and overall coverage is 1.75 hours above nominal. Week 1 * Ahead has two 720 kbps passes on Wednesday, Jan 5 using stations 14 and 43. There are 14 passes during the week, and overall coverage is nominal * Behind has 720 kbps passes on Monday, Jan 3 (D63), Tuesday, Jan 4 (D43), Wednesday, Jan 5 (D63), Thursday, Jan 6 (D63), and Friday, Jan 7 (D63). There are 14 passes during the week, and overall coverage is nominal. Other * The current anticipated date for the SSC move within Goddard is Monday, Nov 29. The system will be shut down the night before the move. Users should anticipate that it may take a couple of days to bring the system back online. The entire SDAC system is moving over, including both SOHO and STEREO. * A new particle has appeared on the COR1-A objective lens on Nov 19. A calibration roll is needed as soon as convenient. APL is looking into scheduling this for Dec 7. This particle appeared in exact conjunction with a debris storm which occured at 16:00 UT. COORDINATED OBSERVATIONS ------------------------ ------------------------------------------------------------------------------- Scheduled activities for Week 47: M Nov 22 (326) Ahead: 720 kbps downlink on station 14 Behind: 720 kbps downlink on station 63 T Nov 23 (327) Ahead: 720 kbps downlink on station 63 W Nov 24 (328) T Nov 25 (329) US Thanksgiving F Nov 26 (330) Behind: 720 kbps downlink on station 14 S Nov 27 (331) S Nov 28 (332) Ahead: 720 kbps downlink on station 14 Notes: * APL closed both Nov 25 and Nov 26 ------------------------------------------------------------------------------- Scheduled activities for Week 48: M Nov 29 (333) Ahead: 720 kbps downlink on station 14 T Nov 30 (334) W Dec 01 (335) Ahead: 720 kbps downlink on station 63 Behind: Shadow track on station 25 T Dec 02 (336) Ahead: Momentum dump, 15:00 UT Ahead: 720 kbps downlink on station 63 F Dec 03 (337) Behind: 720 kbps downlink on station 63 S Dec 04 (338) Ahead: 720 kbps downlink on station 63 S Dec 05 (339) Behind: 720 kbps downlink on station 63 ------------------------------------------------------------------------------- Scheduled activities for Week 49: M Dec 06 (340) T Dec 07 (341) Ahead: 720 kbps downlink on station 43 W Dec 08 (342) Behind: 720 kpbs downlink on station 63 T Dec 09 (343) F Dec 10 (344) S Dec 11 (345) S Dec 12 (346) ------------------------------------------------------------------------------- Scheduled activities for Week 50: M Dec 13 (347) Ahead: 720 kbps downlink on station 43 T Dec 14 (348) W Dec 15 (349) Behind: Momentum dump, 17:30 UT Behind: 720 kpbs downlink on station 63 T Dec 16 (350) Ahead: 720 kbps downlink on station 43 F Dec 17 (351) S Dec 18 (352) Ahead: 720 kbps downlink on station 63 S Dec 19 (353) ------------------------------------------------------------------------------- Scheduled activities for Week 51: M Dec 20 (354) Ahead: 720 kbps downlink on station 43 Behind: 720 kpbs downlink on station 63 T Dec 21 (355) Behind: 720 kpbs downlink on station 63 W Dec 22 (356) Ahead: 720 kbps downlink on station 43 T Dec 23 (357) Behind: 720 kpbs downlink on station 14 F Dec 24 (358) S Dec 25 (359) Christmas Ahead: 720 kbps downlink on station 43 Behind: 720 kpbs downlink on station 43 S Dec 26 (360) Notes: * APL will be closed on Dec 24 ------------------------------------------------------------------------------- Scheduled activities for Week 52: M Dec 27 (361) T Dec 28 (362) W Dec 29 (363) Ahead: 720 kbps downlink on station 43 T Dec 30 (364) F Dec 31 (365) Behind: 720 kpbs downlink on station 43 S Jan 01 (001) New Years S Jan 02 (002) Notes: * APL will be closed on Dec 31 ------------------------------------------------------------------------------- Scheduled activities for Week 01: M Jan 03 (003) Behind: 720 kpbs downlink on station 63 T Jan 04 (004) Behind: 720 kpbs downlink on station 43 W Jan 05 (005) Ahead: 720 kbps downlink on both stations 14 and 43 Behind: 720 kpbs downlink on station 63 T Jan 06 (006) Behind: 720 kpbs downlink on station 63 F Jan 07 (007) Behind: 720 kpbs downlink on station 63 S Jan 08 (008) S Jan 09 (009) ------------------------------------------------------------------------------- Upcoming events: 2011: * Jan 12 Both: HGA calibration * Feb 6 STEREO spacecraft at 180 degree separation * 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 * 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