STEREO Weekly Meeting Minutes for 2015-11-24 (Week 48) ANNOUNCEMENTS ------------- INSTRUMENT and SPACECRAFT STATUS -------------------------------- * Ahead is operating nominally on the main lobe of the high gain antenna with a one degree offset. * There are currently no communications with the Behind spacecraft. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 47 (Nov 16-22) * On day 321 (Nov 17), during the DSS-63 support for Ahead, turbo decoder lock was lost at 0946z. This anomaly resulted in the loss of one frame of SSR data. * On day 321 (Nov 17), during the ESA DSS-84 support for Ahead, initial telemetry acquisition was 5 minutes delayed due to an incorrect downlink rate configuration. Later in the support, the command bind was lost at 2032z. After the station switched command servers, the MOC was able to rebind successfully to the command link at 2215z. This resulted in postponing the IMPACT SWEA high voltage ramping to the next day. * On day 322 (Nov 18), during the DSS-43 support for Ahead, the telemetry bind was lost at 2235z due to a network anomaly at JPL. The MOC successfully rebound to the telemetry server at 2239z. This resulted in the loss of 4 minutes of real-time telemetry. See DR# N110143 for more information. * On day 323 (Nov 19), the 4th uplink array test for STEREO using DSS-26 and 25 with Ahead was successfully conducted by the DSN. The new configuration tested consisted of two 34m stations utilizing the 80 kW transmitter on DSS-26 and the 20 kW transmitter on DSS-25 with the HGA main lobe, riding along a one degree offset, with the MOC sending no-op commands. An approximately 3 dBm increase in received signal power was demonstrated when the DSS-25 uplink was phased to the DSS-26 uplink at the spacecraft with all 20 no-op commands being received correctly using the 7.8125 bps uplink rate. The total received power, compared to a standard 70 meter or 34 meter support, is still being analyzed. * On day 324 (Nov 20), during the DSS-63 support for Ahead, turbo decoder lock was lost intermittently between 0941z and 1053z. This anomaly resulted in the loss of 12 frames of SSR data. * On day 324 (Nov 20), during the DSS-43 support for Ahead, at BOT, telemetry lock was lost intermittently from 2010z and 2014z. This anomaly resulted in the loss of 1184 frames of real-time and SECCHI and spacecraft SSR data (about 30 seconds). See DR# C111529 for more information. * On day 325 (Nov 21), a Return-To-Service (RTS) engineering demo was conducted with DSS-55 on Ahead. The purpose was to validate X-band tracking performance after the completion of the depot level maintenance. All test objectives were met successfully. Tracking, telemetry, and command data from this support were non-committed. * The Ahead observatory operated nominally during this week resuming operations on the HGA main lobe riding along a one degree offset to prevent overheating of the HGA feed assembly which was at 119 degrees C with the HGA angle at 7.1 degrees and increasing, with respect to the spacecraft-Sun line. After 15 months of side lobe and superior solar conjunction operations, on day 321, November 17th, nominal daily science operations resumed. * On day 320 (Nov 16), during the DSS-63 support for Ahead, after verifying that all in-situ science data recorded since the start of side lobe operations in August 2014 was received by the MOC, the SSR was successfully reconfigured for nominal science operations by loading DHS release 1.1.11 to C&DH RAM. The real-time telemetry queue for SECCHI housekeeping data was operating as expected. * On day 321 (Nov 17), during the DSS-63 support for Ahead, the MOC finished configuring the Ahead spacecraft bus for returning to nominal science operations by loading MOps Macro release 1.1.28 to C&DH RAM at 1054z. After 454 days of side lobe and solar conjunction operations on the Ahead observatory, daily SSR playback, commanding, and tracking operations have resumed. The space weather broadcast has resumed transmitting SECCHI images and the small amount of spacecraft housekeeping data has been removed. * On day 321 (Nov 17), during the ESA DSS-84 support for Ahead, the IMPACT SWEA and STE instruments were powered on at 1808z, after being off for 15 months due to very limited telemetry bandwidth. * On day 322 (Nov 18), during the DSS-43 support for Ahead, the real-time telemetry table was switched to RTDFD #23 at 2043z to provide IMPACT science APIDs to monitor SWEA high voltage ramp-up and STE reconfiguration. The IMPACT team successfully completed bringing up SWEA and STE to their respective science configurations. * On day 323 (Nov 19), the SWAVES SSR science partition (#13) on Ahead filled at 1241z for 11.7 hours. * Processing status of the in-situ instrument space weather data recorded during the 15 months of side lobe operations: This week, the following days were processed with the associated data products available on the MOC STEREO Data Server and GSFC SSC websites: Day 2014-331 through day 2015-245 (November 27th, 2014 through September 2, 2015) * There was some discussion about the new telemetry files being produced for the side lobe period. SWAVES reports a number of .oar files being produced--this is normal, and the files should eventually go away. SWAVES also reports that the pattern of telemetry files being produced is confusing, with full-size .ptp files for a couple of days in a row, and then nothing. Other instrument teams report similar issues. It was decided that the MOC would produce a final version of the telemetry files with the .fin extension, and with a version number higher than any of the .ptp files. * The average daily science data return for Ahead, with the HGA on the main lobe riding along a one degree offset, was 2.9 Gbits during this week. * The fourth uplink array test for recovering Behind is discussed above. A fifth array test with Ahead is scheduled for January 14. This test will combine three 34 meter stations, two broadcasting at 20 kbps, and station 26 broadcasting at 80 kbps. By that point the high gain antenna should be back on the center of the main lobe, and the received power should be about twice that of a 70 meter station. Arrangements have been made with Green Bank and Arecibo to listen for the carrier wave from Behind in conjunction with the DSN attempts. Week 48 (Nov 23-29) * Ahead starts the week at an SPE angle of 6.4 degrees, with a nominal 70 meter telemetry rate of 360 kbps. * Yesterday, Nov 23, G&C parameter release 1.3.4 was written to EEPROM and G&C parameters were dumped from RAM. * APL will be closed for the Thanksgiving holiday Thursday and Friday, Nov 26-27. * Ahead has 9 passes during the week, all at 360 kbps, and overall coverage is nominal. * Behind starts the week at an SPE angle of 3.5 degrees. There will be no passes for Behind during the week. Recovery operations resume the following week. Week 49 (Nov 30-Dec 6) * Ahead starts the week at an SPE angle of 6.5 degrees, riding the HGA soft stop. * The nominal rate on Ahead for 70 meter stations will increase to 480 kbps on Monday, Nov 30. * On Monday, Nov 30, updated fault protection release 2.3.18 (no gyro operations release) will be written to RAM. * The 82nd momentum dump for Ahead is scheduled for Dec 2, with ignition at 23:00 UT. Since this will be the first momentum dump under no-gyro operations, the dump will be shortened so that the target momentum is zero N-m-s, i.e. about half the normal dump. The telemetry rate will also be reduced to 360 kbps to maintain telemetry lock in case the pointing varies during the dump. * Ahead has 7 passes during the week, and overall coverage is nominal. Six passes are at 480 kbps, and one pass is at 360 kbps (for the momentum dump). * Behind starts the week at an SPE angle of 3.9 degrees. * Behind recovery operations resume on Monday, Nov 30. There will be three passes over three days each week. The first two passes, both 4.5 hours, on Monday, Nov 30, and Tuesday, Dec 1, will attempt to power up the battery, and the third pass (4 hours), on Wednesday, Dec 2, will attempt to command on the transmitter. Time has been requested from the Arecibo and Green Bank observatories to listen during the Dec 2 pass. Week 50 (Dec 7-13) * Ahead starts the week at an SPE angle of 6.6 degrees, riding the HGA soft stop, with a nominal 70 meter telemetry rate of 480 kbps. * On Tuesday, Dec 8, C&DH release 1.1.11 and macro parameters 1.1.28 will be written to EEPROM. * A return-to-service track for station 34 is scheduled for Friday, Dec 11, with downlink at 120 kps. There will be no instrument commanding or SSR playback during the track. * Ahead has 10 tracks during the week, eight at 480 kbps, and two at 120 kbps, and overall coverage is short 2.9 hours between Friday to Sunday, Dec 11-13. * Behind starts the week at an SPE angle of 4.3 degrees. Recovery efforts for Behind are scheduled for Thursday, Friday, and Saturday, Dec 10-12. Week 51 (Dec 14-20) * Ahead starts the week at an SPE angle of 6.8 degrees. * On Monday, Dec 14, the downlink rate for 34 m stations for Ahead will increase to 160 kbps. * Also on Monday, Dec 14, updated fault protection rules 2.3.18 for no-gyro-operations will be written to EEPROM. * Ahead has nine tracks during the week, with seven tracks at 480 kbps, one track at 240 kbps (station 26), and one track at 160 kbps. Overall coverage is short 7.9 hours between Monday and Saturday (DOY 348 to 353). No loss of data for the in-situ instruments is anticipated, but SECCHI should plan for the shortfall. * Behind starts week with SPE angle of 4.7 deg. Recovery efforts for Behind are scheduled with three tracks Monday-Thursday, Dec 14-17. Week 52 (Dec 21-27) * The 83rd momentum on Ahead is scheduled for Monday, Dec 21, with ignition at 15:30 UT. This dump is scheduled earlier than usual because the previous momentum dump was short. The telemetry rate will be switched to 96 kbps during the dump to maintain lock. * APL will be closed on Friday, Dec 25, for the Christmas holiday. * Ahead has 10 passes during the week, seven at 480 kbps, and three at 160 kbps. * Behind starts the week at an SPE angle of 5.2 degrees. Recovery efforts for Behind are Thursday, Friday, and Saturday, Dec 24-26. Week 53 (Dec 28-Jan 3) * On Monday, Dec 28, the downlink rate for 70 meter stations for Ahead will increase to 720 kbps. The HGA will be centered on the main lobe on Dec 30. * APL will be closed on Friday, Jan 1, for the New Year holiday. * Ahead has 10 tracks during the week, and overall coverage is nominal. Six tracks are at 720 kbps, one at 240 kbps, and three at 160 kbps. * Behind starts the week at an SPE angle of 5.7 degrees. Recovery efforts for Behind are Wednesday, Thursday, and Friday, Dec 30-Jan 1. * If Behind is recovered by then, the high gain antenna will be on the main lobe with a 1 degree offset on Jan 2. Week 01 (Jan 4-10) * Ahead has 10 tracks during the week, and overall coverage is nominal. There are four tracks at 720 kbps, two at 240 kbps, and four at 160 kbps. * Recovery efforts for Behind are Monday, Tuesday, and Wednesday, Jan 4-6. The battery recovery tracks will be performed with the 80 kW transmitter on station 26. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 48: M Nov 23 (327) Ahead: 96 kbps on 34 meter stations T Nov 24 (328) W Nov 25 (329) T Nov 26 (330) Thanksgiving F Nov 27 (331) S Nov 28 (332) S Nov 29 (333) Notes: * No tracks for Behind due to superior solar conjunction. ------------------------------------------------------------------------------- Scheduled activities for Week 49: M Nov 30 (334) Ahead: HGA on main lobe, riding soft stop, 480 kbps Ahead: 120 kbps on 34 meter stations Behind: Resume Behind recovery efforts T Dec 01 (335) W Dec 02 (336) Ahead: Begin No Gyro Operations (NGO) Ahead: First NGO momentum dump, 23:00 UT T Dec 03 (337) F Dec 04 (338) S Dec 05 (339) S Dec 06 (340) ------------------------------------------------------------------------------- Scheduled activities for Week 50: M Dec 07 (341) T Dec 08 (342) W Dec 09 (343) T Dec 10 (344) F Dec 11 (345) Ahead: Return-to-service track with station 34. S Dec 12 (346) S Dec 13 (347) ------------------------------------------------------------------------------- Scheduled activities for Week 51: M Dec 14 (348) Ahead: 160 kbps on 34 meter stations T Dec 15 (349) W Dec 16 (350) T Dec 17 (351) F Dec 18 (352) S Dec 19 (353) S Dec 20 (354) ------------------------------------------------------------------------------- Scheduled activities for Week 52: M Dec 21 (355) Ahead: Momentum dump, 15:30 UT T Dec 22 (356) 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) Ahead: Main lobe, riding soft stop, 720 kbps (70 m) T Dec 29 (363) W Dec 30 (364) Ahead: HGA on main lobe 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) W Jan 06 (006) T Jan 07 (007) F Jan 08 (008) S Jan 09 (009) S Jan 10 (010) ------------------------------------------------------------------------------- Upcoming events: Behind events are contingent on recovering the spacecraft. 2016: * Jan 2 Behind: HGA on main lobe, offpoint 1 degree, 240 kbps Behind: Resume space weather broadcast to NOAA stations * Jan 5 Behind: HGA on main lobe, riding soft stop, 360 kbps Behind: SSR playback and reconfiguration * Jan 6 Behind: Instrument recommissioning, IMPACT SWEA/STE on * Jan 9 Behind: HGA on main lobe, riding soft stop, 480 kbps * Jan 11 Behind: HGA on main lobe, riding soft stop, 720 kbps * Jan 12 Ahead: First NGO SECCHI stepped calib. roll (date TBC) Behind: HGA on main lobe * Jan 27 Both: HGA calibration (NGO) * Mar 3 Behind: Resume LGA uplink capability on 70 m DSN * Apr 6 Ahead: Resume LGA uplink capability on 70 m DSN * May 16 Both: Post Solar Conjunction Assessment Review * Jul 5 Juno arrival at Jupiter * Dec Behind: Resume LGA downlink capability on 70 m DSN 2017: 2018: * Mar 5 Ahead: Mercury transit 2019: * Mar Ahead: Switch downlink rate to 240 kbps for 34 meter * Apr Behind: Switch downlink rate to 240 kbps for 34 meter 2020: * May Behind: Switch downlink rate to 360 kbps for 34 meter * Jun Ahead: Switch downlink rate to 360 kbps for 34 meter * Jun Behind: Switch downlink rate to 480 kbps for 34 meter * Sep Ahead: Switch downlink rate to 480 kbps for 34 meter 2021: * Jul Behind: Switch downlink rate to 720 kbps for 34 meter * Aug Ahead: Switch downlink rate to 720 kbps for 34 meter