STEREO Weekly Meeting Minutes for 2016-12-20 (Week 51) ANNOUNCEMENTS ------------- * On day 348 (Dec 13), NASA Space Communications and Navigation (SCaN) honored the efforts for the first recovery attempt of STEREO Behind by presenting certificates of recognition to the teams at GSFC, DSN, and JHU/APL. * The MOC did not receive two IDR files for AHEAD from the DSN on day 350, Thursday, Dec 15th. These files have been transmitted and the missing data, including new level 0 files (version 05), should be available later today (Dec 20). * The normally scheduled weekly telecon for next Tuesday, Dec 27, has been cancelled due to the holidays. INSTRUMENT and SPACECRAFT STATUS -------------------------------- * Ahead is operating nominally on the main lobe of the high gain antenna. * Attempts to recover Behind have transitioned back to a monthly schedule. DISCUSSION AND OPERATIONS CONSTRAINTS ------------------------------------- Week 50 (Dec 12-18) * On day 350 (Dec 15), the STEREO project received authorization to continue ESA cross support for 2017. The MOC has already started to schedule ESA passes in 2017. * On day 351 (Dec 16), during the DSS-25 support for Ahead, turbo decoder lock was lost intermittently beginning at 2042z through 2122z. This anomaly resulted in the loss of 30 frames of SSR data. * On day 348 (Dec 13), the 37th SECCHI stepped calibration was executed at 0655z for aphelion in the Ahead orbit. This was the 6th SECCHI stepped calibration roll to be conducted without gyro use. * The Ahead observatory operated nominally during this week. * On day 353 (Dec 18), the PLASTIC SSR science partition (#17) on Ahead filled and began recording only housekeeping data at 0243z for 1.2 hours due to an unexpected shortage of track time. The shortage occured right before the start of a scheduled track, and it was originally expected that the available storage would be sufficient to carry through the start of the track. * The average daily science data return for Ahead was 5.0 Gbits during this week. * On day 351 (Dec 16), during a 2.5 hour support for Behind with the 34m station DSS-26 using the 80 KW transmitter to minimize 70m contentions, 260 commands were transmitted during the support. No carrier was detected by either the DSN station or the radio science receiver team after attempting to power on the TWTA for 30 minutes. Transitioned to battery recovery operations for the remainder of the support which consists of repeatedly sweeping a 3 kHz uplink range and sending commands for IEM switched power and PDU 1553 interface bus off. * On day 353 (Dec 18), during a 2.5 hour support for Behind with DSS-43, 260 commands were transmitted during the support. No carrier was detected by either the DSN station or the radio science receiver team after attempting to power on the TWTA for 30 minutes. Transitioned to battery recovery operations for the remainder of the support which consists of repeatedly sweeping a 3 kHz uplink range and sending commands for IEM switched power and PDU 1553 interface bus off. * On day 353 (Dec 18), during the DSS-14 support for Behind, commanding was delayed 32 minutes because the transmitter could not be calibrated. Once the issue was resolved, the uplink was successfully established and a total of 319 commands were sent during the support. The delay in commanding caused three command blocks to be missed. No carrier was detected by either the DSN station or the radio science receiver team during the support. See DR# G117691 for more information. * The Behind status is unchanged. Monthly attempts to recover the spacecraft continue. The next recovery attempts are scheduled for Jan 20-22. Week 51 (Dec 19-25) * The 94th momentum dump on Ahead was carried out successfully this morning (Dec 20). * Sunday, Dec 25, is Christmas. Hanukkah runs from Dec 24 to Jan 1. * Ahead has 9 passes during the week, and overall coverage is nominal. There are six passes at 720 kbps, two at 240 kbps, and one at 160 kbps. * Behind starts the week at an SPE angle of 15.3 degrees. There are no tracks for Behind during the week. Week 52 (Dec 26-Jan 1) * Monday, Dec 26, is a holiday at APL. * The JPL NOPS office will be closed Dec 26, 27, but will be on call. * New Year's Day is Sunday, Jan 1. * A leap second will be added at the end of the UT day on Saturday, Dec 31. The leap second will be implemented onboard with time tagged commands. Spacecraft clock SPICE kernel files have been incorporated into SolarSoft. * The station 43 support for Ahead on Dec 31 has been reduced in duration to avoid any problems with the year rollover and the leap second that would otherwise occur during the track. * Ahead has 11 passes during the week, and overall coverage is nominal. There are 9 tracks at 720 kbps, and two at 240 kbps. * Behind starts the week at an SPE angle of 15.7 degrees. There are no tracks for Behind during the week. Week 1 (Jan 2-8) * Monday, Jan 2, is the observed New Year holiday. * Ahead has 11 passes during the week, and overall coverage is nominal. There are five tracks at 720 kbps, one at 240 kbps, and five at 160 kbps. * There are no tracks for Behind during the week. Week 2 (Jan 9-15) * Ahead has 9 passes during the week, and overall coverage is nominal. There are eight passes at 720 kbps, and one at 240 kbps. * Behind has no passes during the week. Week 3 (Jan 16-22) * Monday, Jan 16, is Martin Luther King Day. This is a federal holiday, but APL will be open. * The 95th momentum dump on Ahead is scheduled for Thursday, Jan 19, with ignition at 21:00 UT. This will be the 14th dump without using the gyros. * Federal government offices in the DC area will be closed on Friday, Jan 20, for the presidential inauguration. * Ahead has 8 passes during the week, and overall coverage is nominal. There are five passes at 720 kbps, two at 240 kbps, and one at 160 kbps. * Battery recovery tracks are on Friday, Jan 20, with station 14, and on Saturday, Jan 21, with the 80 kW transmitter on station 26. A carrier recovery track will be carried out with station 14 on Sunday, Jan 22. The radio science receiver will be used with the station 14 tracks. Week 4 (Jan 23-29) * Ahead has 9 passes during the week, and overall coverage is now nominal. An additional pass with station 63 was added on Tuesday. There are currently six tracks at 720 kbps, one at 240 kbps, and two at 160 kbps. * Behind has no passes during the week. Week 5 (Jan 30-Feb 5) * Ahead has 12 tracks during the week, and overall coverage is nominal. There are five passes at 720 kbps, one at 360 kbps, three at 240 kbps, and two at 160 kbps. Two ESA Malargue passes were added for Jan 30,31. * Behind has no passes during the week. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 51: M Dec 19 (354) T Dec 20 (355) Ahead: Momentum dump, 15:30 UT W Dec 21 (356) T Dec 22 (357) F Dec 23 (358) S Dec 24 (359) S Dec 25 (360) Christmas ------------------------------------------------------------------------------- Scheduled activities for Week 52: M Dec 26 (361) Christmas holiday T Dec 27 (362) W Dec 28 (363) T Dec 29 (364) F Dec 30 (365) S Dec 31 (366) S Jan 01 (001) New Year ------------------------------------------------------------------------------- Scheduled activities for Week 01: M Jan 02 (002) New Year holiday T Jan 03 (003) W Jan 04 (004) T Jan 05 (005) F Jan 06 (006) S Jan 07 (007) S Jan 08 (008) ------------------------------------------------------------------------------- Scheduled activities for Week 02: M Jan 09 (009) T Jan 10 (010) W Jan 11 (011) T Jan 12 (012) F Jan 13 (013) S Jan 14 (014) S Jan 15 (015) ------------------------------------------------------------------------------- Scheduled activities for Week 03: M Jan 16 (016) Martin Luther King Day T Jan 17 (017) W Jan 18 (018) T Jan 19 (019) Ahead: Momentum dump, 21:00 UT F Jan 20 (020) Inauguration Day Behind: Battery recovery track with station 14 S Jan 21 (021) Behind: Battery recovery track with station 26 S Jan 22 (022) Behind: Carrier recovery track with station 14 ------------------------------------------------------------------------------- Scheduled activities for Week 04: M Jan 23 (023) T Jan 24 (024) W Jan 25 (025) T Jan 26 (026) F Jan 27 (027) S Jan 28 (028) S Jan 29 (029) ------------------------------------------------------------------------------- Scheduled activities for Week 05: M Jan 30 (030) T Jan 31 (031) W Feb 01 (032) T Feb 02 (033) F Feb 03 (034) S Feb 04 (035) S Feb 05 (036) ------------------------------------------------------------------------------- Upcoming events: Behind events are contingent on recovering the spacecraft. 2016: * 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 2022: 2023: * May 5 Behind: Mercury transit * Jul 17 Behind: Closest approach to Earth * Aug 13 Ahead: Closest approach to Earth 2024: 2025: * Apr 7 Ahead: Mercury transit 2026: 2027: * Feb 1 Behind: Mercury transit 2028: 2029: * Jun 30 Ahead: Mercury transit