STEREO Weekly Meeting Minutes for 2017-02-21 (Week 8) ANNOUNCEMENTS ------------- * The subsystem telemetry assesment review for Behind will be held at APL on Feb 24. See below for details. 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 7 (Feb 13-19) * On day 045 (Feb 14), during the DSS-63 support for Ahead, a DSN demonstration test was conducted to verify end-to-end tracking, telemetry, and commanding utilizing test TTC software V1.3. As this was a test track, there was no SSR playback or instrument commanding. All required and planned activities were executed as planned. * On day 045 (Feb 14), during the DSS-14 support for Ahead, symbol lock was lost beginning at 2327z through 2330z due to an intermittent receiver issue. Later in the support, turbo decoder lock was lost intermittently between 046-0134z through 0153z. These anomalies resulted in the loss of 6100 frames of real-time telemetry and SSR data, corresponding to approximately 1 minute's worth of data for all the instruments. See DR# G117907 for more information. * On day 048 (Feb 17), during the DSS-36 support for Ahead, turbo decoder lock was lost intermittently between 2324z through 049-0146z due to periods of rain at the Canberra complex. This anomaly resulted in the loss of 8542 frames of real-time and SSR data, corresponding to approximately 5 minutes of instrument data. See DR# N110535 for more information. * On day 048 (Feb 17), the 96th momentum dump on Ahead was executed successfully at 1930z, which imparted an estimated delta V of 0.093 m/sec. This was the 15th momentum dump that did not use the IMU. After thruster operations completed, there was a 1.05 degree of roll angle error which was dampened out over the next 7.25 minutes. Fine pointing stabilized 2.8 minutes after completion of the momentum dump. * On day 049 (Feb 18), the SECCHI instrument reset at 22:27:11z. The SECCHI team reconfigured the instrument to operational mode by 050-1400z. This was the 43rd reset of SECCHI on the Ahead observatory. * The average daily science data return for Ahead was 5.3 Gbits during this week. * On day 048 (Feb 17), during a 3.75 hour support for Behind with the 34m station DSS-26 using the 80 KW transmitter to minimize 70m contentions, 400 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 049 (Feb 18), during a 3.75 hour support for Behind with the 34m station DSS-26 using the 80 KW transmitter to minimize 70m contentions, 400 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 050 (Feb 19), during a 4 hour support for Behind with DSS-14, 420 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. Week 8 (Feb 20-26) * Yesterday (Feb 20) G&C Memory Object Release 1.3.5 was loaded to G&C EEPROM on Ahead. * The subsystem telemetry assesment review for Behind will be held at APL on Friday, Feb 24, in building 200, room E273, starting at 9:00. A revised invitations will be sent out, and will include WebEx information. Please contact the MOC if you plan to attend, as escorting to the meeting site will be required. * Ahead has 11 passes during the week, and overall coverage is nominal. There are eight passes at 720 kbps, and three at 160 kbps. * There are no passes for Behind during the week. Week 9 (Feb 27-Mar 5) * Ahead has 11 passes during the week, and overall coverage is nominal. There are ten passes at 720 kbps and one at 240 kbps. * There are no passes for Behind during the week. Week 10 (Mar 6-12) * Daylight Savings time in the US begins on March 12. * Ahead has 9 passes during the week, and overall coverage is nominal. There are seven passes at 720 kbps, one at 240 kbps, and one at 160 kbps. * There are no passes for Behind during the week. Week 11 (Mar 13-19) * The 38th SECCHI stepped calibration roll is scheduled for Thursday, Mar 16, starting at 13:50 UT. The system momentum is expected to be 6 N-m-s. This will be the 7th roll without using the gyros. * Ahead has 10 passes during the week, and overall coverage is nominal. There are eight passes at 720 kbps, one at 240 kbps, and one at 160 kbps. * Recovery attempts for Behind are scheduled for Friday, Saturday, and Sunday, Mar 17-19. The first two passes are for battery recovery, and will use the 80 kW transmitter on station 26. The radio science receiver will be used for all three tracks. Week 12 (Mar 20-26) * 97th momentum dump on Ahead is scheduled for 20:30 UTC on Wednesday, Mar 22. This will be the 16th momentum dump without using the gyros * Ahead has 9 passes during the week, and overall coverage is nominal. There are eight passes at 720 kbps and one at 240 kbps. * There are no passes for Behind during the week. Week 13 (Mar 27-Apr 2) * Ahead has 11 passes during the week, and overall coverage is nominal. There are six passes at 720 kbps, four at 240 kbps, and one at 160 kbps. * There are no passes for Behind during the week. Week 14 (Apr 3-9) * Ahead has 9 passes during the week, and overall coverage is nominal. There are seven passes at 720 kbps, and two passes at 240 kbps. * There are no passes for Behind during the week. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 08: M Feb 20 (051) T Feb 21 (052) W Feb 22 (053) T Feb 23 (054) F Feb 24 (055) Behind: Subsystem telemetry review S Feb 25 (056) S Feb 26 (057) ------------------------------------------------------------------------------- Scheduled activities for Week 09: M Feb 27 (058) T Feb 28 (059) W Mar 01 (060) T Mar 02 (061) F Mar 03 (062) S Mar 04 (063) S Mar 05 (064) ------------------------------------------------------------------------------- Scheduled activities for Week 10: M Mar 06 (065) T Mar 07 (066) W Mar 08 (067) T Mar 09 (068) F Mar 10 (069) S Mar 11 (070) S Mar 12 (071) Daylight savings time begins ------------------------------------------------------------------------------- Scheduled activities for Week 11: M Mar 13 (072) T Mar 14 (073) W Mar 15 (074) T Mar 16 (075) Ahead: SECCHI calibration roll, 13:50 F Mar 17 (076) Behind: Battery recovery track with station 26 S Mar 18 (077) Behind: Battery recovery track with station 26 S Mar 19 (078) Behind: Carrier recovery track with station 14 ------------------------------------------------------------------------------- Scheduled activities for Week 12: M Mar 20 (079) T Mar 21 (080) W Mar 22 (081) Ahead: 97th momentum dump, 20:30 UT T Mar 23 (082) F Mar 24 (083) S Mar 25 (084) S Mar 26 (085) ------------------------------------------------------------------------------- Scheduled activities for Week 13: M Mar 27 (086) T Mar 28 (087) W Mar 29 (088) T Mar 30 (089) F Mar 31 (090) S Apr 01 (091) S Apr 02 (092) ------------------------------------------------------------------------------- Scheduled activities for Week 14: M Apr 03 (093) T Apr 04 (094) W Apr 05 (095) T Apr 06 (096) F Apr 07 (097) S Apr 08 (098) S Apr 09 (099) ------------------------------------------------------------------------------- Upcoming events: Behind events are contingent on recovering the spacecraft. 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