STEREO Weekly Meeting Minutes for 2016-11-15 (Week 46) ANNOUNCEMENTS ------------- * None 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 45 (Nov 7-13) * On day 317 (Nov 12), during the DSS-24 support for Ahead, turbo decoder lock was lost briefly at 2051z and again at 2129z. This anomaly resulted in the loss of two frames of SSR data. * On day 317 (Nov 12), the PLASTIC SSR science partition (#17) on Ahead filled and began overwriting at 1028z for 8.7 hours due to an unexpected shortage of track time. * On day 317 (Nov 12), the SWAVES SSR science partition (#13) on Ahead filled and began overwriting at 1330z for 5.6 hours due to an unexpected shortage of track time. * There was some discussion about why the PLASTIC and SWAVES partitions overran, but the IMPACT partition did not. The IMPACT team is aware that they can increase their telemetry rate under normal conditions, but are waiting for the winter DSN conflict period to be over before doing so. * The average daily science data return for Ahead was 4.8 Gbits during this week. * On day 316 (Nov 11), during a 4.5 hour support for Behind with the 34m station DSS-26 using the 80 KW transmitter to minimize 70m contentions, 480 commands were transmitted during the support. No carrier was detected by the DSN after attempting to power on the TWTA for 30 minutes, but this is to be expected with a 34 meter station. Transitioned to battery recovery operations which consisted of repeatedly sweeping a 3 kHz uplink range and sending commands for IEM switched power and PDU 1553 interface bus off. * On day 318 (Nov 13), during the DSS-26 support for Behind, the transmitter tripped off shortly after BOT at 1606z. The station was unable to resolve the issue prior to EOT. Of the 380 commands that were expected to be transmitted, only 13 were radiated before the transmitter tripped. Since the transmitter high voltage on command was not sent, there was no chance of detecting a carrier signal during this support. See DR #G117611 for more information. * On day 318 (Nov 13), during a 2.6 hour support for Behind with DSS-14, 280 commands were transmitted during the support. No carrier was detected by the DSN after attempting to power on the TWTA for 30 minutes. Transitioned to battery recovery operations which consisted of repeatedly sweeping a 3 kHz uplink range and sending commands for IEM switched power and PDU 1553 interface bus off. Week 46 (Nov 14-20) * Macros release 1.1.30 was written to C&DH EEPROM yesterday (Nov 14). This reorders the antenna configuration after system recovery back to the way it was before solar conjunction and side lobe operations. The spacecraft will come back on the -Z antenna for the first 24 hours, then the high gain antenna, and then the +Z antenna, and will remain on the lowest data rate. * A PIT test was done yesterday (Nov 14) in parallel with the station 25 pass for Ahead. This test was undertaken with a backup workstation, and didn't affect the track. The data from the test looked good--no differences were seen between the two workstations. * The 93rd momentum dump for Ahead is scheduled for tomorrow (Nov 16), with ignition at 14:30 UT. This will be the 12 dump without the gyros. * Ahead has 11 passes during the week, and overall coverage is nominal. There are three passes at 720 kbps, one at 240 kbps, and seven at 160 kbps. * Behind starts the week at an SPE angle of 13.9 degrees. There are no passes scheduled for Behind during the week, as recovery attempts for Behind are back to a monthly schedule. Week 47 (Nov 21-27) * Thursday, Nov 24, is Thanksgiving. Both Thursday and Friday are holidays at APL. * Ahead has 13 passes during the week. Three ESA New Norcia passes were added on Monday and Tuesday to make up for the previous shortage, and overall coverage is now nominal. There are four tracks scheduled at 720 kbps, three at 240 kbps, and six at 160 kbps. * Behind starts the week at an SPE angle of 14.1 degrees. There are currently no passes scheduled for Behind during the week. Week 48 (Nov 28-Dec 4) * Ahead has 9 passes during the week, and overall coverage is now nominal. An ESA New Norcia pass was added on Monday. There are now four passes at 720 kbps, three at 240 kbps, and two at 160 kbps. * Behind starts the week at an SPE angle of 14.4 degrees. There are no tracks for Behind scheduled during the week. Week 49 (Dec 5-11) * There's a 2 hour project interface test with station 26 on day 346 (Dec 11) to test out new DTT software. There will be no SSR playback or instrument commanding during this track. * Ahead has 9 passes during the week, and overall coverage is nominal. There are five passes at 720 kbps, two at 240 kbps, and two at 160 kbps. A 3 hour ESA Malargue pass was added on Wednesday, Dec 7. * Behind starts the week at an SPE angle of 14.6 degrees. The previously scheduled recovery tracks have been moved to the following week to assist the Juno mission with planned perijove maneuvers. Week 50 (Dec 12-18) * The 37th SECCHI stepped calibration roll is scheduled for Tuesday, Dec 13, starting at 06:55 UT. This will be the perihelion roll. System momentum is expected to be 6 N-m-s. This will be the sixth roll without using the gyros. * Ahead has 9 tracks during the week, and overall coverage is nominal. There are six passes at 720 kbsp, two at 240 kbps, and one at 160 kbps. * Behind starts the week at an SPE angle of 15.0 degrees. Battery recovery passes are scheduled for Friday, Dec 16, using the 80 kW transmitter on station 26, and on Sunday, Dec 18, with station 43. Later on Sunday is a carrier recovery track with station 14. Week 51 (Dec 19-25) * The 94th momentum dump on Ahead is scheduled for 15:30 UT on Tuesday, Dec 20. This will be the 13th dump without using the gyros. * 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. * 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. Spacecraft clock SPICE kernel files will be available shortly. * 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. COORDINATED OBSERVATIONS ------------------------------------------------------------------------------- Scheduled activities for Week 46: M Nov 14 (319) T Nov 15 (320) W Nov 16 (321) Ahead: Momentum dump, 14:30 UT T Nov 17 (322) F Nov 18 (323) S Nov 19 (324) S Nov 20 (325) ------------------------------------------------------------------------------- Scheduled activities for Week 47: M Nov 21 (326) T Nov 22 (327) W Nov 23 (328) T Nov 24 (329) Thanksgiving F Nov 25 (330) S Nov 26 (331) S Nov 27 (332) ------------------------------------------------------------------------------- Scheduled activities for Week 48: M Nov 28 (333) T Nov 29 (334) W Nov 30 (335) T Dec 01 (336) F Dec 02 (337) S Dec 03 (338) S Dec 04 (339) ------------------------------------------------------------------------------- Scheduled activities for Week 49: M Dec 05 (340) T Dec 06 (341) W Dec 07 (342) T Dec 08 (343) F Dec 09 (344) S Dec 10 (345) S Dec 11 (346) Ahead: Project interface test with station 26 ------------------------------------------------------------------------------- Scheduled activities for Week 50: M Dec 12 (347) T Dec 13 (348) Ahead: SECCHI stepped calibration roll, 06:55 UT W Dec 14 (349) T Dec 15 (350) F Dec 16 (351) Behind: Battery recovery track with station 26 S Dec 17 (352) S Dec 18 (353) Behind: Battery recovery track with station 43 Behind: Carrier recovery track with station 14 ------------------------------------------------------------------------------- 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 ------------------------------------------------------------------------------- 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